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Forest Management (forest + management)

Distribution by Scientific Domains
Life Sciences65%
Earth and Environmental Science15%
Humanities and Social Sciences11%
2 Other Domains9%
Distribution within Life Sciences
Ecology & Organismal Biology20%
Entomology10%

Kinds of Forest Management

  • sustainable forest management
    		•

    Terms modified by Forest Management

  • forest management practice
    		•

    Selected Abstracts

    MODELING IMPACTS OF BIOENERGY MARKETS ON NONINDUSTRIAL PRIVATE FOREST MANAGEMENT IN THE SOUTHEASTERN UNITED STATES

    NATURAL RESOURCE MODELING, Issue 3 2009
    ANDRES SUSAETA
    Abstract The potential impacts of bioenergy markets on slash pine plantation management on nonindustrial private forestlands in the southeastern United States were analyzed. We developed an integrated Black,Scholes and modified Hartman model to achieve this task. The risk of damage from catastrophic natural disturbances such as wildfires and pest outbreaks associated with the exclusion/incorporation of thinnings and variation in timber salvage rates was also included. Three scenario sets were considered:,status quo,or,no thinning scenario, thinning scenario for pulpwood,,and,thinning scenario for bioenergy,at differing levels of risk and salvage. The results indicated that the incorporation of thinnings either for pulpwood or bioenergy increases the forestland value regardless of the risk when the salvage value of the stand is 0.8. When the two thinning scenarios were compared, the land expectation value for the,thinning scenario for bioenergy,was greater at any level of risk compared with the,thinning scenario for pulpwood, averaging a difference of 11.5% and 11.7% for salvageable portions of 0.8 and 0, respectively. [source]

    Flawed Meta-Analysis of Biodiversity Effects of Forest Management

    CONSERVATION BIOLOGY, Issue 4 2010
    PANU HALME
    No abstract is available for this article. [source]

    Effects of Forest Management on Amphibians and Reptiles in Missouri Ozark Forests

    CONSERVATION BIOLOGY, Issue 1 2004
    ROCHELLE B. RENKEN
    Within even-aged management sites, we also focused on the local-scale effects of clearcutting on these species by comparing relative abundance among plots located within clearcut stands, 50 m away from clearcut stands, and 200 m away from clearcut stands. Pretreatment sampling of species abundance occurred from 1992 through 1995, and post-treatment sampling occurred from 1997 through 2000. At the landscape scale, treatment significantly affected the abundance of Bufo americanus. This species declined less on even-aged management sites than on control sites, but the general decline on all sites suggests that other factors may have contributed to this result. Within even-aged management sites, most amphibian species declined and some reptile species increased relative to pretreatment abundances within clearcut stands. We found significant effects of distance from clearcut for two amphibian species, Ambystoma maculatum and Rana clamitans, and two reptile species, Scincella lateralis and Sceloporus undulatus. In general, we conclude that clearcuts within even-aged management sites locally affected amphibian and reptile species but, at a larger spatial scale, we did not detect significant effects of even-aged and uneven-aged forest management. These findings represent relatively short-term data but suggest that forest management and maintenance of biodiversity may be compatible when relatively small amounts of the landscape are disturbed. Resumen:,Como parte del Proyecto Ecosistema del Bosque Ozark de Missouri (PEBOM), evaluamos experimentalmente los impactos de la gestión de bosques sobre la abundancia relativa de anfibios y reptiles en los bosques Ozark, Missouri (E.U.A.). Utilizando sitios de estudio extensos (es decir, de tamaño promedio de 400ha) como la unidad experimental, estudiamos los efectos de tratamientos de manejo de bosques de edad uniforme y dispar comparados con el manejo sin cosecha (es decir, control) sobre la abundancia relativa de 13 especies focales de anfibios y reptiles. En los sitios de manejo de edad uniforme, también analizamos los efectos a escala local de la tala completa sobre estas especies comparando la abundancia relativa entre parcelas localizadas dentro de los claros talados, a 50 m y 200 m de los claros. Para determinar la abundancia de especies, se tomaron muestras previas al tratamiento de 1992 a 1995, y muestras posteriores al tratamiento de 1997 a 2000. A la escala de paisaje, el tratamiento afectó significativamente la abundancia de Bufo americanus. La abundancia de esta especie disminuyó menos en sitios de manejo de edad uniforme que en los sitios control, pero la disminución general en todos los sitios sugiere que otros factores pudieron haber contribuido a este resultado. En los sitios de manejo de edad uniforme, la abundancia de la mayoría de las especies de anfibios disminuyó y algunas especies de reptiles incrementaron en relación con las abundancias previas al tratamiento dentro de los claros talados. Encontramos efectos significativos de la distancia del claro para dos especies de anfibios, Ambystoma maculatum y Rana clamitans, y dos especies de reptiles, Scincella lateralis y Sceloporus undulatus. En general, concluimos que la tala en sitios de edad uniforme afectó localmente a las especies de anfibios y reptiles, pero a una mayor escala espacial, no detectamos impactos significativos entre el manejo de sitios de edad uniforme y dispar. Estos hallazgos representan datos de relativamente corto plazo pero sugieren que la gestión de bosques y el mantenimiento de la biodiversidad pueden ser compatibles cuando se perturban superficies relativamente pequeñas del paisaje. [source]

    Heterogeneity, Group Size and Collective Action: The Role of Institutions in Forest Management

    DEVELOPMENT AND CHANGE, Issue 3 2004
    Amy R. Poteete
    Collective action for sustainable management among resource-dependent populations has important policy implications. Despite considerable progress in identifying factors that affect the prospects for collective action, no consensus exists about the role played by heterogeneity and size of group. The debate continues in part because of a lack of uniform conceptualization of these factors, the existence of non-linear relationships, and the mediating role played by institutions. This article draws on research by scholars in the International Forestry Resources and Institutions (IFRI) research network which demonstrates that some forms of heterogeneity do not negatively affect some forms of collective action. More importantly, IFRI research draws out the interrelations among group size, heterogeneity, and institutions. Institutions can affect the level of heterogeneity or compensate for it. Group size appears to have a non-linear relationship to at least some forms of collective action. Moreover, group size may be as much an indicator of institutional success as a precondition for such success. [source]

    Ownership and Incentives in Joint Forest Management: A Survey

    DEVELOPMENT POLICY REVIEW, Issue 1 2005
    Tuukka Castrén
    The relationship between the state and communities has been an overriding issue in the development of forestry institutions globally. In many countries, the trend is for communities to become co-managers of public forests. Meanwhile, in development co-operation both poverty and multiple rural livelihoods have received increased attention. In this article, the potential of joint community-state management of forests is discussed. Forest production has several characteristics that make it suitable for joint management where both parties benefit. Involving communities in management decreases the state's monitoring costs, while communities benefit from better access to market information. For this to take place, however, the state forest apparatus needs to be free from undue rent-seeking. The most advantageous solutions are case- and context-specific. [source]

    Toward Adaptive Community Forest Management: Integrating Local Forest Knowledge with Scientific Forestry,

    ECONOMIC GEOGRAPHY, Issue 1 2002
    Daniel James Klooster
    Abstract: This case study of indigenous communities in highland Michoacán, Mexico, examines data on forest change, woodcutting practices, social history, and a recent forest inventory and management plan prepared by a professional forester. It assesses the social and environmental fit of both local knowledge and scientific forestry and considers their abilities to contribute to sustainable forest management. Both bodies of knowledge are limited in their ability to inform the social practice of environmental management. The local forest knowledge system is particularly hampered by a limited ability to monitor the forest's response to woodcutting, while scientific forestry lacks the institutional flexibility to ensure the just and effective implementation of restrictions and prescriptions. This article recommends cross-learning between scientific resource managers and woodcutters, participatory environmental monitoring to assess the results of different cutting techniques, and explicit management experiments to facilitate institutional learning at the community level. This kind of adaptive management approach permits the flexible integration of local knowledge, scientific forestry, and appropriate institutional parameters to modulate human needs and goals with the discordant harmonies of inhabited and heavily used forests in a constant state of flux under processes of succession, disturbance, and spatial variation. Several barriers to this kind of institutional innovation exist, but outside intervention has the potential to change the dynamics of institutional evolution. [source]

    Nest Selection by Cavity-nesting Birds in Subtropical Montane Forests of the Andes: Implications for Sustainable Forest Management

    BIOTROPICA, Issue 3 2009
    Natalia Politi
    ABSTRACT Development of sustainable forestry has been hampered in tropical countries by a scarcity of research on the ecological effects of logging. We focused on cavity-nesting birds, a group known to be sensitive to logging. Cavities used for nesting were not a random subset of all available suitable cavities. Birds selected cavities that were relatively high above the ground, had smaller entrances, and were excavated by woodpeckers. The use of tree species was also not random: Calycophyllum multiflorum, Blepharocalyx gigantea, and Podocarpus parlatorei were disproportionately important. Cavity nests were also more likely to be found in areas with trees with high mean diameter at breast height. This study emphasizes the need to maintain some unlogged forest patches within logging areas and retain certain species of trees. This study has implications for forest management in Argentina, where a new law mandates the sustainable use of forest resources and where many landowners are interested in forest certification. RESUMEN En los países tropicales la implementación del manejo forestal sostenible se ha visto limitado debido a la escasez de estudios sobre los efectos ecológicos de la explotación forestal. Nos focalizamos en aves que nidifican en huecos de árboles porque este es un grupo sensible a las prácticas de manejo forestal. Los huecos en árboles utilizados para nidificar no fueron un conjunto al azar de todos los huecos adecuados disponibles. Las aves seleccionaron huecos en árboles que estaban a una altura elevada desde el suelo, con entradas chicas y excavadas por carpinteros. El uso de las especies de árboles tampoco fue al azar: Calycophyllum multiflorum, Blepharocalyx gigantea y Podocarpus parlatorei fueron desproporcionadamente importantes. Fue más probable encontrar nidos en parches de árboles que tuvieron un promedio de diámetro a la altura del pecho más alto. Este estudio resalta la necesidad de retener algunos parches del bosque sin intervención dentro del área de manejo y retener ciertas especies arbóreas. Este estudio tiene implicancias en el manejo forestal en Argentina, donde una nueva ley plantea un uso sostenible de los recursos forestales y donde muchos propietarios están interesados en obtener una certificación forestal. [source]

    Organic mound-building ants: their impact on soil properties in temperate and boreal forests

    JOURNAL OF APPLIED ENTOMOLOGY, Issue 4 2008
    M. F. Jurgensen
    Abstract Ants are important components of most soil invertebrate communities, and can affect the flow of energy, nutrients and water through many terrestrial ecosystems. The vast majority of ant species build nests in the mineral soil, but a small group of ants in temperate and boreal forests of Eurasia and North America build large parts of their nests above-ground using organic materials collected from the surrounding soil. Many studies have shown that ants nesting in mineral soil can affect water infiltration rates, soil organic matter (OM) content, and nutrient cycling, but much less is known on how mound-building ants influence soil physical and chemical properties. In this paper we summarize what is known on the soil impacts of organic mound-building ants in temperate and boreal forests, and how these ants could be affected by ecosystem disturbance and future climate change. Much of this information comes from studies on Formica rufa group ants in Europe, which showed that CO2 emissions and concentrations of C, N, and P are usually higher in ant mounds than in the surrounding forest soil. However, ant mounds are a minor component of total soil C and nutrient pools, but they do increase spatial heterogeneity of soil water and available nutrients. Mound-building ants can also impact tree growth, which could change the quantity and quality of OM added to soil. Forest management, fire, and projected climate change, especially in boreal forests, could affect mound-building ant population dynamics, and indirectly, soil properties. [source]

    Patch-Occupancy Modeling as a Method for Monitoring Changes in Forest Floristics: a Case Study in Southeastern Australia

    CONSERVATION BIOLOGY, Issue 3 2009
    TRENT D. PENMAN
    fuego prescrito; manejo adaptativo; modelo Bayesiamo; silvicultura; tala Abstract:,The ability to monitor changes in biodiversity is fundamental to demonstrating sustainable management practices of natural resources. Disturbance studies generally focus on responses at the plot scale, whereas landscape-scale responses are directly relevant to the development of sustainable forest management. Modeling changes in occupancy is one way to monitor landscape-scale responses. We used understory vegetation data collected over 16 years from a long-term study site in southeastern Australia. The site was subject to timber harvesting and frequent prescribed burning. We used occupancy models to examine the impacts of these disturbances on the distribution of 50 species of plants during the study. Timber harvesting influenced the distribution of 9 species, but these effects of harvesting were generally lost within 14 years. Repeated prescribed fire affected 22 species, but the heterogeneity of the burns reduced the predicted negative effects. Twenty-two species decreased over time independent of treatment, and only 5 species increased over time. These changes probably represent a natural response to a wildfire that occurred in 1973, 13 years before the study began. Occupancy modeling is a useful and flexible technique for analyzing monitoring data and it may also be suitable for inclusion within an adaptive-management framework for forest management. Resumen:,La habilidad para monitorear cambios en la biodiversidad es fundamental para demostrar el manejo sustentable de los recursos naturales. Los estudios de perturbación generalmente enfocan las respuestas a escala de parcela, mientras que las respuestas a escala de paisaje son directamente relevantes para el desarrollo del manejo sustentable de bosques. El modelado de cambios en la ocupación es una forma de monitorear respuestas a escala de paisaje. Utilizamos datos de la vegetación de sotobosque colectados a los largo de 16 años en un sitio de estudio a largo plazo en el sureste de Australia. El sitio fue sujeto a la cosecha de madera y a quemas prescritas frecuentes. Utilizamos modelos de ocupación para examinar los impactos de estas perturbaciones sobre la distribución de 50 especies de plantas. La cosecha de madera influyó en la distribución de nueve especies, pero los efectos de la cosecha generalmente se perdieron al cabo de 14 años. El fuego prescrito repetido afectó a 22 especies, pero la heterogeneidad de las quemas redujo los efectos negativos pronosticados. Veintidós especies decrecieron en el tiempo independientemente del tratamiento, y solo cinco especies incrementaron en el tiempo. Estos cambios probablemente representan una respuesta natural al incendio no controlado que ocurrió en 1973, 13 años antes de que comenzara el estudio. El modelado de la ocupación es una técnica útil y flexible para analizar datos de monitoreo y también puede ser adecuado para su inclusión en un marco de manejo adaptativo para la gestión de bosques. [source]

    Beyond Reaping the First Harvest: Management Objectives for Timber Production in the Brazilian Amazon

    CONSERVATION BIOLOGY, Issue 4 2007
    DANIEL J. ZARIN
    manejo de bosques; producción sostenida; sustentabilidad; tala de impacto reducido Abstract:,Millions of hectares of future timber concessions are slated to be implemented within large public forests under the forest law passed in 2006 by the Brazilian Congress. Additional millions of hectares of large, privately owned forests and smaller areas of community forests are certified as well managed by the Forest Stewardship Council, based on certification standards that will be reviewed in 2007. Forest size and ownership are two key factors that influence management objectives and the capacity of forest managers to achieve them. Current best ecological practices for timber production from Brazil's native Amazon forests are limited to reduced-impact logging (RIL) systems that minimize the environmental impacts of harvest operations and that obey legal restrictions regarding minimum diameters, rare species, retention of seed trees, maximum logging intensity, preservation of riparian buffers, fire protection, and wildlife conservation. Compared with conventional, predatory harvesting that constitutes >90% of the region's timber production, RIL dramatically reduces logging damage and helps maintain forest cover and the presence of rare tree species, but current RIL guidelines do not assure that the volume of timber removed can be sustained in future harvests. We believe it is counterproductive to expect smallholders to subscribe to additional harvest limitations beyond RIL, that larger private forested landholdings managed for timber production should be sustainable with respect to the total volume of timber harvested per unit area per cutting cycle, and that large public forests should sustain volume production of individual harvested species. These additional requirements would improve the ecological sustainability of forest management and help create a stable forest-based sector of the region's economy, but would involve costs associated with lengthened cutting cycles, reduced harvest intensities, and/or postharvest silviculture to promote adequate growth and regeneration. Resumen:,Bajo la nueva ley forestal aprobada en 2006 por el Congreso Brasileño, millones de hectáreas de bosques públicos están destinadas a constituir futuras concesiones madereras. Millones de hectáreas adicionales de extensos bosques privados y áreas reducidas de bosques comunitarios están certificadas por el Forest Stewardship Council por su buen manejo, con base en estándares de certificación que serán revisados en 2007. La extensión y tenencia del bosque son dos factores clave que influyen en los objetivos de manejo y en la capacidad de los manejadores para alcanzarlos. Las mejores prácticas ecológicas actuales para la producción de madera en los bosques de la Amazonía Brasileña están limitadas a sistemas de tala de impacto reducido (TIR) que minimizan los impactos ambientales de las operaciones de cosecha y que obedecen restricciones legales en relación con los diámetros mínimos, las especies raras, la retención de árboles semilla, la máxima intensidad de tala, la preservación de amortiguamientos ribereños, la protección del fuego y la conservación de vida silvestre. En comparación con la cosecha convencional, depredadora, mediante la cual se obtiene >90% de la producción de madera en la región, la TIR dramáticamente reduce el daño y ayuda a mantener la cobertura del bosque y la presencia de especies de árboles raras, pero los actuales lineamientos de TIR no aseguran que el volumen de madera removida pueda ser sostenido en futuras cosechas. Consideramos que es contraproducente esperar que los pequeños propietarios suscriban límites a la cosecha más allá de la TIR; que los bosques privados manejados para la producción de madera debieran ser sustentables respecto al volumen total de madera cosechada por unidad de área por ciclo de corte; y que los bosques públicos deberían sustentar el volumen de producción de especies individuales. Estos requerimientos adicionales mejorarían la sustentabilidad ecológica del manejo de bosques y ayudaría a crear un sector forestal estable en la economía regional, pero implicarían costos asociados con la prolongación de los ciclos de corte, la reducción de las intensidades de cosecha y/o la silvicultura postcosecha para promover el crecimiento adecuado y la regeneración. [source]

    The Northwest Forest Plan as a Model for Broad-Scale Ecosystem Management: a Social Perspective

    CONSERVATION BIOLOGY, Issue 2 2006
    SUSAN CHARNLEY
    conservación y desarrollo; comunidades rurales; gestión forestal; monitoreo socioeconómico Abstract:,I evaluated the Northwest Forest Plan as a model for ecosystem management to achieve social and economic goals in communities located around federal forests in the U.S. Pacific Northwest. My assessment is based on the results of socioeconomic monitoring conducted to evaluate progress in achieving the plan's goals during its first 10 years. The assessment criteria I used related to economic development and social justice. The Northwest Forest Plan incorporated economic development and social justice goals in its design. Socioeconomic monitoring results indicate that plan implementation to achieve those goals met with mixed success, however. I hypothesize there are two important reasons the plan's socioeconomic goals were not fully met: some of the key assumptions underlying the implementation strategies were flawed and agency institutional capacity to achieve the goals was limited. To improve broad-scale ecosystem management in the future, decision makers should ensure that natural-resource management policies are socially acceptable; land-management agencies have the institutional capacity to achieve their management goals; and social and economic management goals (and the strategies for implementing them) are based on accurate assumptions about the relations between the resources being managed and well-being in local communities. One of the difficulties of incorporating economic development and social justice goals in conservation initiatives is finding ways to link conservation behavior and development activities. From a social perspective, the Northwest Forest Plan as a model for ecosystem management is perhaps most valuable in its attempt to link the biophysical and socioeconomic goals of forest management by creating high-quality jobs for residents of forest communities in forest stewardship and ecosystem management work, thereby contributing to conservation. Resumen:,Evalué el Plan Forestal del Noroeste como un modelo para la gestión de ecosistemas para alcanzar metas sociales y económicas en comunidades localizadas alrededor de bosques federales en el Pacífico Noroeste de E.U.A. Mi evaluación se basa en los resultados del monitoreo socioeconómico desarrollado para evaluar el progreso en el logro de las metas del plan durantes sus 10 primeros años. Los criterios de evaluación que utilicé se relacionan con el desarrollo económico y la justicia social. El diseño del Plan Forestal del Noroeste incorporó metas de desarrollo económico y de justicia social. Sin embargo, los resultados del monitoreo socioeconómico indican que éxito en la implementación del plan para alcanzar esas metas fue combinado. Postulé la hipótesis de que hay dos razones importantes por las que las metas socioeconómicas del plan no se cumplieron totalmente: algunas de las suposiciones clave en las estrategias de implementación fueron deficientes y la capacidad institucional de la agencia para alcanzar las metas era limitada. Para mejorar la gestión de ecosistemas a gran escala en el futuro, los tomadores de decisiones deberán asegurarse que las políticas de gestión de recursos naturales sean aceptables socialmente; que las agencias de gestión de tierras tengan la capacidad institucional para cumplir sus metas de gestión; y que las metas de gestión sociales y económicas (y las estrategias para su implementación) se basen en suposiciones precisas de las relaciones entre los recursos a gestionar y el bienestar de las comunidades locales. La manera de vincular comportamiento de conservación y actividades de desarrollo es una de las dificultades para la incorporación de metas de desarrollo económico y de justicia social en las iniciativas de conservación. Desde una perspectiva social, el Plan Forestal del Noroeste como modelo para la gestión de ecosistemas quizás es más valioso por su intento de vincular las metas biofísicas y socioeconómicas de la gestión forestal mediante la creación de empleos de alta calidad para residentes de las comunidades en labores de regulación y supervisión forestal y de gestión de ecosistemas, por lo tanto contribuye a la conservación. [source]

    Effects of Forest Management on Amphibians and Reptiles in Missouri Ozark Forests

    CONSERVATION BIOLOGY, Issue 1 2004
    ROCHELLE B. RENKEN
    Within even-aged management sites, we also focused on the local-scale effects of clearcutting on these species by comparing relative abundance among plots located within clearcut stands, 50 m away from clearcut stands, and 200 m away from clearcut stands. Pretreatment sampling of species abundance occurred from 1992 through 1995, and post-treatment sampling occurred from 1997 through 2000. At the landscape scale, treatment significantly affected the abundance of Bufo americanus. This species declined less on even-aged management sites than on control sites, but the general decline on all sites suggests that other factors may have contributed to this result. Within even-aged management sites, most amphibian species declined and some reptile species increased relative to pretreatment abundances within clearcut stands. We found significant effects of distance from clearcut for two amphibian species, Ambystoma maculatum and Rana clamitans, and two reptile species, Scincella lateralis and Sceloporus undulatus. In general, we conclude that clearcuts within even-aged management sites locally affected amphibian and reptile species but, at a larger spatial scale, we did not detect significant effects of even-aged and uneven-aged forest management. These findings represent relatively short-term data but suggest that forest management and maintenance of biodiversity may be compatible when relatively small amounts of the landscape are disturbed. Resumen:,Como parte del Proyecto Ecosistema del Bosque Ozark de Missouri (PEBOM), evaluamos experimentalmente los impactos de la gestión de bosques sobre la abundancia relativa de anfibios y reptiles en los bosques Ozark, Missouri (E.U.A.). Utilizando sitios de estudio extensos (es decir, de tamaño promedio de 400ha) como la unidad experimental, estudiamos los efectos de tratamientos de manejo de bosques de edad uniforme y dispar comparados con el manejo sin cosecha (es decir, control) sobre la abundancia relativa de 13 especies focales de anfibios y reptiles. En los sitios de manejo de edad uniforme, también analizamos los efectos a escala local de la tala completa sobre estas especies comparando la abundancia relativa entre parcelas localizadas dentro de los claros talados, a 50 m y 200 m de los claros. Para determinar la abundancia de especies, se tomaron muestras previas al tratamiento de 1992 a 1995, y muestras posteriores al tratamiento de 1997 a 2000. A la escala de paisaje, el tratamiento afectó significativamente la abundancia de Bufo americanus. La abundancia de esta especie disminuyó menos en sitios de manejo de edad uniforme que en los sitios control, pero la disminución general en todos los sitios sugiere que otros factores pudieron haber contribuido a este resultado. En los sitios de manejo de edad uniforme, la abundancia de la mayoría de las especies de anfibios disminuyó y algunas especies de reptiles incrementaron en relación con las abundancias previas al tratamiento dentro de los claros talados. Encontramos efectos significativos de la distancia del claro para dos especies de anfibios, Ambystoma maculatum y Rana clamitans, y dos especies de reptiles, Scincella lateralis y Sceloporus undulatus. En general, concluimos que la tala en sitios de edad uniforme afectó localmente a las especies de anfibios y reptiles, pero a una mayor escala espacial, no detectamos impactos significativos entre el manejo de sitios de edad uniforme y dispar. Estos hallazgos representan datos de relativamente corto plazo pero sugieren que la gestión de bosques y el mantenimiento de la biodiversidad pueden ser compatibles cuando se perturban superficies relativamente pequeñas del paisaje. [source]

    Mexico's Community-Managed Forests as a Global Model for Sustainable Landscapes

    CONSERVATION BIOLOGY, Issue 3 2003
    David Barton Bray
    On the other hand, conservationists have declared that the only way to stem the tide of deforestation is to place as many tracts as possible under strict protection. In this context, Mexico presents a national laboratory for studying the social and ecological benefits of delivering forests to local people. As a little-noticed result of the Mexican Revolution in the second decade of the twentieth century, well over half of the forests of Mexico were placed in community-held lands. In historic struggles that passed through several phases, most of these communities have now gained substantial control over the use of their forests. Because of the substantial degree of social capital in rural forms of organization in Mexico, this control of forest resources has led to an estimated 290,479 community forest enterprises ( CFEs ), through which communities are producing timber on their own lands. New studies are beginning to suggest that important gains in both social and economic justice, good forest management, and biodiversity protection are resulting from the actions of these CFEs. As more forests globally are being devolved to local communities, it is important to carry out more research on the Mexican model of community forest management for timber production. Resumen: Investigadores preocupados por el manejo sostenible de bosques en los trópicos han argumentado que el camino para una custodia mas efectiva de los recursos forestales es la transferencia de la responsabilidad a las comunidades locales que obtienen sustento de ellos. Por otro lado, conservacionistas han declarado que la única manera de detener la ola de deforestación es colocar bajo protección estricta tantas regiones como sea posible. En este contexto, México representa un laboratorio para el estudio de los beneficios sociales y ecológicos de entregar los bosques a los habitantes locales. Como un resultado poco conocido de la Revolución Mexicana, en la segunda década del siglo veinte, más de la mitad de los bosques de México se ubicaban en tierras que estaban en manos de las comunidades. Las comunidades forestales han atravesado por distintas etapas de conflicto, tras la cuáles han obtendio un control sustancial de los usos de sus bosques. Debido al nivel considerable de capital social en formas de organización rural en México, este control de los recursos forestales ha conducido a la integración de entre 290,479 empresas forestales comunitarias ( EFC ), en las que las comunidades están produciendo madera en sus propias tierras. Nuevos estudios están comenzando a sugerir que se están produciendo ganancias importantes en las acciones de estas EFC están generando beneficios importantes, tanto en lo que se refiere a justicia social como económica, la administración correcta de bosques y la protección de la biodiversidad. A medida en que se deleguen mayores extensiones de bosques a comunidades locales, es importante llevar a cabo más investigación sobre el modelo mexicano de manejo comunitario de bosques para la producción de forestal maderable. [source]

    A Strategic Approach to Multistakeholder Negotiations

    DEVELOPMENT AND CHANGE, Issue 2 2001
    David Edmunds
    Environment and development practitioners increasingly are interested in identifying methods, institutional arrangements and policy environments that promote negotiations among natural resource stakeholders leading to collective action and, it is hoped, sustainable resource management. Yet the implications of negotiations for disadvantaged groups of people are seldom critically examined. We draw attention to such implications by examining different theoretical foundations for multistakeholder negotiations and linking these to practical problems for disadvantaged groups. We argue that negotiations based on an unhealthy combination of communicative rationality and liberal pluralism, which underplays or seeks to neutralize differences among stakeholders, poses considerable risks for disadvantaged groups. We suggest that negotiations influenced by radical pluralist and feminist post-structuralist thought, which emphasize strategic behaviour and selective alliance-building, promise better outcomes for disadvantaged groups in most cases, particularly on the scale and in the historical contexts in which negotiations over forest management usually take place. [source]

    Effects of landscape composition and substrate availability on saproxylic beetles in boreal forests: a study using experimental logs for monitoring assemblages

    ECOGRAPHY, Issue 2 2006
    Heloise Gibb
    Intensive forestry practises in the Swedish landscape have led to the loss and fragmentation of stable old-growth habitats. We investigated relationships between landscape composition at multiple scales and the composition of saproxylic beetle assemblages in nine clear-cut, mature managed and old-growth spruce-dominated forest stands in the central boreal zone of Sweden. We set out fresh spruce and birch logs and created spruce snags in 2001,2002 to experimentally test the effects of coarse woody debris (CWD) type and forest management on the composition of early and late successional, and red-listed saproxylic beetle assemblages. We examined effects of CWD availability at 100 m, and landscape composition at 1 and 10 km on saproxylic beetle abundances. Additionally, we tested whether assemblage similarity decreased with increasing distance between sites. We collected beetles from the experimental logs using eclector and window traps in four periods during 2003. CWD was measured and landscape composition data was obtained from maps of remotely sensed data. The composition of saproxylic beetles differed among different CWD substrates and between clear-cuts and the older stand types, however differences between mature managed and old-growth forests were significant only for red-listed species. Assemblage similarities for red-listed species on clear-cuts were more different at greater distances apart, indicating that they have more localised distributions. CWD availability within 100 m of the study sites was rarely important in determining the abundance of species, suggesting that early successional saproxylic beetles can disperse further than this distance. At a larger scale, a large area of suitable stand types within both 1 and 10 km resulted in greater abundances in the study sites for several common and habitat-specific species. The availability of suitable habitat at scales of 1,10 km is thus likely to be important in the survival of many saproxylic species in forestry-fragmented areas. [source]

    To what extent can management variables explain species assemblages?

    ECOGRAPHY, Issue 6 2004
    A study of carabid beetles in forests
    Studies concerning the influence of forest management on invertebrate communities often focus on a limited set of chosen variables and rarely quantify the importance of management as opposed to other influences. We aimed at: 1) comparing the importance for species assemblages of habitat variables defined by management with those independent of it; 2) understanding the ecological significance of the variation remaining when both management and non-management variables are used. We caught carabid beetles according to a stratified pitfall sampling based on forest structure, tree composition and stand age. Forty-nine habitat variables were measured using three spatial scales. We decomposed the variation of species assemblages with successive constrained ordinations based on sets of variables, and studied the life traits of the species least and best explained by the model including all of the variables. Forest structure, composition and stand age showed important effects but explained a relatively small part of the overall variation in species assemblages. Management accounted for ca 30% of the variation, but non-management variables had a significant impact and the interaction between management and non-management sets resulted in significant influences. Most species for which the variation was highly explained by the model were generally large and with inefficient wings, while the least explained species were small. Our study suggests that: 1) even with highly controlled samples, the influence of management on species assemblages should not be studied by a limited set of categorical variables; 2) management variables may interact with factors outside of the manager's control; 3) a significant part of the variation cannot be explained by habitat variables and needs taking ecological processes into account; 4) rules to optimise constrained ordination techniques applied to species-habitat studies can be proposed. [source]

    Toward Adaptive Community Forest Management: Integrating Local Forest Knowledge with Scientific Forestry,

    ECONOMIC GEOGRAPHY, Issue 1 2002
    Daniel James Klooster
    Abstract: This case study of indigenous communities in highland Michoacán, Mexico, examines data on forest change, woodcutting practices, social history, and a recent forest inventory and management plan prepared by a professional forester. It assesses the social and environmental fit of both local knowledge and scientific forestry and considers their abilities to contribute to sustainable forest management. Both bodies of knowledge are limited in their ability to inform the social practice of environmental management. The local forest knowledge system is particularly hampered by a limited ability to monitor the forest's response to woodcutting, while scientific forestry lacks the institutional flexibility to ensure the just and effective implementation of restrictions and prescriptions. This article recommends cross-learning between scientific resource managers and woodcutters, participatory environmental monitoring to assess the results of different cutting techniques, and explicit management experiments to facilitate institutional learning at the community level. This kind of adaptive management approach permits the flexible integration of local knowledge, scientific forestry, and appropriate institutional parameters to modulate human needs and goals with the discordant harmonies of inhabited and heavily used forests in a constant state of flux under processes of succession, disturbance, and spatial variation. Several barriers to this kind of institutional innovation exist, but outside intervention has the potential to change the dynamics of institutional evolution. [source]

    Is it simply getting worse?

    ECONOMIC HISTORY REVIEW, Issue 4 2008
    Agriculture, Swedish greenhouse gas emissions over 200 years
    This paper challenges the idea that emissions of greenhouse gases simply increase over time with income. It adopts a 200-year perspective and includes the important flows of greenhouse gases related to agriculture, not just the CO2 from fossil fuels. The result is that the pattern of Swedish total greenhouse gas emissions over time resembles an N. In contrast, when only emissions from fossil fuels are counted, the pattern over time resembles an inverted U. Among the most important factors generating emissions in agriculture, forest management was especially important, but in addition, draining of wetlands for agriculture played a substantial role. [source]

    Spatial,temporal marked point processes: a spectrum of stochastic models

    ENVIRONMETRICS, Issue 3-4 2010
    Eric Renshaw
    Abstract Many processes that develop through space and time do so in response not only to their own individual growth mechanisms but also in response to interactive pressures induced by their neighbours. The growth of trees in a forest which compete for light and nutrient resources, for example, provides a classic illustration of this general spatial,temporal growth-interaction process. Not only has its mathematical representation proved to be a powerful tool in the study and analysis of marked point patterns since it may easily be simulated, but it has also been shown to be highly flexible in terms of its application since it is robust with respect to incorrect choice of model selection. Moreover, it is highly amenable to maximum likelihood and least squares parameter estimation techniques. Currently the algorithm comprises deterministic growth and interaction coupled with a stochastic arrival and departure mechanism. So for systems with a fixed number of particles there is an inherent lack of randomness. A variety of different stochastic approaches are therefore presented, from the exact event,time model through to the associated stochastic differential equation, taking in time-increment and Tau- and Langevin-Leaping approximations en route. The main algorithm is illustrated through application to forest management and high-intensity packing of hard particle systems, and comparisons are made with the established force biased approach. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    White pines, Ribes, and blister rust: integration and action

    FOREST PATHOLOGY, Issue 3-4 2010
    R. S. Hunt
    Summary The preceding articles in this series review the history, biology and management of white pine blister rust in North America, Europe and eastern Asia. In this integration, we connect and discuss seven recurring themes important for understanding and managing epidemics of Cronartium ribicola in the white pines (five-needle pines in subgenus Strobus). Information and action priorities for research and management of the pathogen, telial and aecial hosts, and their interactions are listed in a detailed Appendix. Syntheses focused on genetics, plant disease, invasive species or forest management have provided alternative but knowledgeable lessons on the white pine blister rust pathosystem. Two critical issues for the conservation of white pines are to sustain ecosystems affected by blister rust and to maintain genetic diversity for adaptive traits such as disease resistance. Forest genetics includes tree improvement and molecular techniques for research; their application can increase rust resistance by artificial and natural selection. Silviculture augments genetics with methods to deploy and enhance resistance as well as to regenerate and tend white pine stands. Although cultivated or wild Ribes might serve as inoculum sources, silviculture and horticulture can reduce the risk of serious impacts from blister rust using genetics for breeding and epidemiology for hazard assessment and disease control. Climate change threatens to cause major alterations in temperature and precipitation regimes, resulting in maladapted conifers succumbing to various diseases and insect outbreaks. In contrast, many white pine species have broad ecological ranges and are tolerant of harsh environments,traits that permit successful establishment and growth over wide geographic and altitudinal zones. Given appropriate management, white pines could thrive as valuable commercial and ecologically important keystone species. In an uncertain environment, adaptive management provides a learning and participatory approach for sustaining resilient ecosystems. [source]

    Comparison of structure and biodiversity in the Rajhenav virgin forest remnant and managed forest in the Dinaric region of Slovenia

    GLOBAL ECOLOGY, Issue 3 2000
    Andrej Boncina
    Abstract Comparisons are made between a virgin forest remnant (primeval forest) and a lightly managed (near-to-nature) forest with regard to horizontal forest structures, the structure of forest stands, and the diversity of plant and bird species. In the virgin forest remnant the proportion of canopy gaps is smaller, there are no stands in the developmental phase of a pole stand (10 < cm d.b.h. < 30 cm), and both the growing stock and the proportion of less vigorous trees are considerably greater. In addition, there is a higher percentage of dead trees, a smaller proportion of minor tree species and a considerably lower diversity of plants. The diversity of bird species is similar for each forest type, but rare bird species are confined to the virgin forest remnant. The biological differences between the two types of forest have led to changes in the physical site conditions. The results of the research are valuable in assessing the consequences of near-to-nature forest management. [source]

    Influences of restock age and habitat patchiness on Tree Pipits Anthus trivialis breeding in Breckland pine plantations

    IBIS, Issue 2007
    NIALL H.K. BURTON
    The British Tree Pipit Anthus trivialis population has shown a marked decline in recent decades, together with a range contraction that has been most apparent in central and southeast England. In East Anglia, the species is now largely restricted to heathland and, in particular, the conifer plantations established on light soils in these areas. Here I evaluate how Tree Pipits are influenced by the age of pine restock and the patchiness of habitat in Thetford Forest in the Breckland area of Norfolk and Suffolk, eastern England. Both the probability of occurrence and the densities of territory-holding Tree Pipits varied according to the age of coupes of restock , densities peaking in restock 1,6 years old , and were also significantly higher in coupes (a stand comprising one or more forest subcompartments planted in the same year, usually with the same tree crop) in the largest, most central forest block than in smaller, isolated blocks peripheral to this. Within coupes, the distribution and thus densities of Tree Pipits were limited by the availability of songposts. Few songflights finished on the ground or in flight and displaying birds only perched on restock once trees were at least 3 years old (0.8 m high) , thus, territories were only established away from bordering or retained mature trees once restock had reached this age. Pairing success was reduced among males with territories of less than 1 ha, as found in the highest densities in restock, but was unrelated to the proportion of songflights that individuals finished on perches. Thus, although the availability of songposts limited the distribution of the species, it did not appear to affect individual breeding success. The study highlights the importance of pine plantations for the species in lowland England, but also the benefits of large blocks of habitat and targeted forest management, for instance, the retention of mature trees in coupes of restock for Pipits to use as songposts. [source]

    Using GIS to relate small mammal abundance and landscape structure at multiple spatial extents: the northern flying squirrel in Alberta, Canada

    JOURNAL OF APPLIED ECOLOGY, Issue 3 2005
    MATTHEW WHEATLEY
    Summary 1It is common practice to evaluate the potential effects of management scenarios on animal populations using geographical information systems (GIS) that relate proximate landscape structure or general habitat types to indices of animal abundance. Implicit in this approach is that the animal population responds to landscape features at the spatial grain and extent represented in available digital map inventories. 2The northern flying squirrel Glaucomys sabrinus is of particular interest in North American forest management because it is known from the Pacific North-West as a habitat specialist, a keystone species of old-growth coniferous forest and an important disperser of hypogeous, mycorrhizal fungal spores. Using a GIS approach we tested whether the relative abundance of flying squirrel in northern Alberta, Canada, is related to old forest, conifer forest and relevant landscape features as quantified from management-based digital forest inventories. 3We related squirrel abundance, estimated through live trapping, to habitat type (forest composition: conifer, mixed-wood and deciduous) and landscape structure (stand height, stand age, stand heterogeneity and anthropogenic disturbance) at three spatial extents (50 m, 150 m and 300 m) around each site. 4Relative abundances of northern flying squirrel populations in northern and western Alberta were similar to those previously reported from other regions of North America. Capture rates were variable among sites, but showed no trends with respect to year or provincial natural region (foothills vs. boreal). 5Average flying squirrel abundance was similar in all habitats, with increased values within mixed-wood stands at large spatial extents (300 m) and within deciduous-dominated stands at smaller spatial extents (50 m). No relationship was found between squirrel abundance and conifer composition or stand age at any spatial extent. 6None of the landscape variables calculated from GIS forest inventories predicted squirrel abundance at the 50-m or 150-m spatial extents. However, at the 300-m spatial extent we found a negative, significant relationship between average stand height and squirrel abundance. 7Synthesis and applications. Boreal and foothill populations of northern flying squirrel in Canada appear unrelated to landscape composition at the relatively large spatial resolutions characteristic of resource inventory data commonly used for management and planning in these regions. Flying squirrel populations do not appear clearly associated with old-aged or conifer forests; rather, they appear as habitat generalists. This study suggests that northern, interior populations of northern flying squirrel are probably more related to stand-level components of forest structure, such as food, microclimate (e.g. moisture) and understorey complexity, variables not commonly available in large-scale digital map inventories. We conclude that the available digital habitat data potentially exclude relevant, spatially dependent information and could be used inappropriately for predicting the abundance of some species in management decision making. [source]

    Can niche use in red and grey squirrels offer clues for their apparent coexistence?

    JOURNAL OF APPLIED ECOLOGY, Issue 6 2002
    Jenny Bryce
    Summary 1Introduced species are, world-wide, one of the most serious threats to biodiversity. Grey squirrels Sciurus carolinensis are one of many introduced species to have threatened a native congener; they are thought to have replaced red squirrels Sciurus vulgaris throughout much of the UK as a result of competition. The rate of competitive replacement may be influenced by habitat composition, with some red squirrel populations persisting for prolonged periods in the presence of greys in predominantly coniferous forest. 2Here the similarity of red and grey squirrels' pattern of habitat use was investigated in Craigvinean forest in Scotland, UK, a site that has experienced apparent coexistence for up to 30 years. Overlap was examined in several dimensions: spatial overlap of home ranges, dynamic association and niche overlap. Habitat selection was examined at three levels: selection of core home range areas, selection of tree species within the home range, and the characteristics of patches used intensively by each squirrel species in comparison with random locations within their home range. 3Although there was overlap between red and grey squirrel ranges, there were clear differences in the macrohabitats utilized, with red squirrels selecting areas of Norway spruce Picea abies and grey squirrels selecting riparian corridors of mixed woodland for their home ranges. Within their home ranges, habitat selection by individual red and grey squirrels was similar, but again with reds selecting Norway spruce and greys selecting patches of mixed conifers and broad-leaved trees. As no habitat variables consistently affected the microdistribution of red and grey squirrels within blocks or ,stands' of trees, stands that were used were thought to constitute good and relatively homogeneous habitats for squirrels of either species. 4There was no evidence to suggest that red and grey squirrels avoided using the same areas at the same time, and potential niche overlap was considerable (0·77). However, partitioning of habitats may have reduced competition between red and grey squirrels and hence have contributed to red squirrel persistence at this site. 5This work (i) reinforces earlier proposals that forest management offers a promising tool to assist the conservation of red squirrels; (ii) raises the issue of determining the spatial scale at which coexistence operates; and (iii) offers an illustration of how the management of invasive species can be mediated through the manipulation of niche availability. [source]

    Nest-site limitation and density dependence of reproductive output in the common goldeneye Bucephala clangula: implications for the management of cavity-nesting birds

    JOURNAL OF APPLIED ECOLOGY, Issue 3 2002
    H. Pöysä
    Summary 1,Hole-nesting birds are frequently faced with a shortage of suitable nest sites in regions of intensive forest management. Nest boxes are sometimes provided to alleviate nest-site limitation in cavity-nesting waterfowl and are also recommended for several rare and endangered species. However, the impacts on effective breeding numbers and breeding success have rarely been considered, particularly in instances where density dependence might operate. 2,We experimentally manipulated nest sites to assess limits on the population size of a secondary cavity-nesting species, the common goldeneye Bucephala clangula, living on freshwater lakes. We also examined density dependence in their reproductive output. 3,Breeding pairs were counted in experimental and control areas over a 12-year period; for 4 years (1988,91) before nest box addition (1992,94 in the experimental area) and for 5 years (1995,99) afterwards. Broods were counted each year between 1988 and 1999 to study reproductive output. 4,Mean number of pairs per lake increased after the addition of nest boxes in the experimental area but not in the control area. However, neither the mean number of broods per lake nor the mean number of fledged birds per lake increased significantly in the experimental area. 5,When the whole period of 1988,99 was considered and data pooled from all the lakes, the numbers of broods and fledged birds showed negative density dependence of reproductive output. 6,Our results indicate that nest sites limit the population size of breeding common goldeneye, but show also that density-dependent factors operate to limit reproductive output. The possibility that density dependence may negate management actions directed at increasing breeding numbers in cavity-nesting waterfowl should be considered carefully before taking these actions. This also applies to nest box provisioning programmes aiming to manage populations of endangered species. [source]

    Recovery of bird populations after clearfelling of tall open eucalypt forest in Western Australia

    JOURNAL OF APPLIED ECOLOGY, Issue 5 2001
    M.R. Williams
    Summary 1Increasing concern over the sustainable management of forested landscapes and the extent of forest clearance world-wide has led to a growing interest in the impacts of logging and associated habitat disturbance on biodiversity. 2We conducted an experimental study of the impact of clearfelling on birds of the karri Eucalyptus diversicolor forest in south-west Western Australia over a 17-year period, and a retrospective study of both clearfelled and naturally regenerated karri stands aged from 0 to 146 years. 3One-third of species still had significantly reduced abundance 14 years after disturbance ceased, although all affected species made limited use of regenerating forest. 4Multivariate analysis of changes in bird community structure showed that the effects of disturbance were still evident 14 years after clearfelling. Clearfelling may also have produced some temporary changes in community structure in adjacent unlogged forest. 5Species richness and total abundance of birds declined by 58% and 96%, respectively, in the first year after clearfelling, and 14 years after logging were still 17% and 55% below levels in adjacent undisturbed forest. During this early successional phase both measures increased as a simple function of stand age. Species richness of regrowth reached that of old-growth at 30,50 years and total abundance of all bird species in regrowth was similar to that of old-growth after approximately 70 years. 6Several bird species offer potential as indicators of the ecological sustainability of karri forest management. These species nest in large hollows in standing live trees (two cockatoo species) or have been slow to recolonize immature regrowth karri forests (six species). 7Post-hoc power analysis showed that even the long-term and intensive sampling employed in this study failed to detect declines in abundance of less than 80,90% for most bird species. For many uncommon species, trying to estimate changes in abundance is problematic and likely to require replication which is difficult to achieve in field situations where logged and unlogged forests are compared. Despite this, the present study identified some key impacts of forest clearfelling on bird communities, with implications both for the consequences of clearfelling of forests and the criteria for sustainable forest management. [source]

    A practical method for predicting the short-time trend of bivoltine populations of Ips typographus (L.) (Col., Scolytidae)

    JOURNAL OF APPLIED ENTOMOLOGY, Issue 1 2006
    M. Faccoli
    Abstract:,Ips typographus is the main spruce pest of European forests. In most areas of the Italian Alps there are two generations per year; overwintering adults fly in May looking for trees suitable for breeding, their offspring emerge in summer, 7,8 weeks after tree colonization, and the adults of the second generation emerge in spring of the following year after overwintering under the bark or in the litter. A long-term population monitoring was carried out in north-east Italy with the aim at developing a prediction model able to estimate the population density of the following year. Between 1996 and 2004, pheromone traps monitored populations of I. typographus annually. Monitoring lasted 4 months (May,August), with replacement of pheromone dispensers after 8 weeks. Insects trapped before dispenser change were called ,spring captures' (May,June), and included both overwintering and re-emerging adults. Beetles caught after dispenser change were called ,summer captures' (July,August), and included the adults of the first generation. The results show a high positive correlation between the ratio of summer and spring captures of one year (Summerx/Springx), and the ratio of total captures of the following year (Yx+1) and those of the current year (Yx) (Yx+1/Yx). Summerx/Springx lower than 0.62 indicate decreasing populations in the following year (Yx+1/Yx <1), whereas Summerx/Springx higher than 0.62 indicate increasing populations (Yx+1/Yx >1). The applicability of the model in the study of I. typographus risk of outbreak and in the forest management is discussed. The prediction of the short-time trend of the population allows assessing its density in the following year, and therefore the risk of outbreak. [source]

    Effect of time of year on the development of immature stages of the Large Pine Weevil (Hylobius abietis L.) in stumps of Sitka spruce (Picea sitchensis Carr.) and influence of felling date on their growth, density and distribution

    JOURNAL OF APPLIED ENTOMOLOGY, Issue 3 2004
    R. Moore
    Abstract:, The time of year and time of felling of a commercial stand of Sitka spruce (Picea sitchensis Carr.) were both shown to influence the spatial distribution and development of the large pine weevil, Hylobius abietis (L). Stump and root systems were excavated over a 5-month period in 1997, between 18 and 27 months after felling, and all immature H. abietis removed. On a site with a 6-month spread of felling dates in 1995, mean larval weights in 1997 were higher in stumps from earlier fellings, but H. abietis numbers were higher in stumps from later fellings. This appeared to be due to the continued presence of older, heavier larvae, laid as eggs in 1995, in stumps from earlier fellings, combined with a greater concentration of oviposition having occurred in 1996 in the fresher stumps of later fellings. Pupae were first found in excavated stumps on 12 June 1997 and adults on 29 July 1997. Emergence of the ,new generation' of adult weevils commenced on 7 August 1997. On average, 25% of H. abietis adults emerged in autumn 1997, 41% in 1998 and 34% in 1999. First emergence (1997) was proportionally higher in the areas felled earlier in 1995 than those felled later that year. However, the opposite was found for third emergence (1999) where emergence was greater for stumps created later in 1995. Larger stumps contained greater densities of H. abietis. Total ,potential' emergence was estimated to be between 46400 and 170825 H. abietis/ha. However, emergence traps indicated that only 40,80% managed to complete their development and emerge successfully. It is suggested that within-season felling date may be one of the most important factors affecting larval development, distribution and abundance; as well as subsequent damage levels associated with adult feeding. Consequently, knowledge of felling date could be crucial to developing methods of integrated forest management for this major forest pest. [source]

    The implications of improved communications for participatory forest management in Tanzania

    AFRICAN JOURNAL OF ECOLOGY, Issue 2009
    Elizabeth J. Z. Robinson
    Abstract Following the 1998 National Forest Policy and Forest Act of 2002, participatory forest management (PFM) is being introduced in Tanzania. PFM has two key objectives: to reduce forest degradation thereby increasing ecosystem services, and to improve the livelihoods of local villagers. A unique data set collected in 2006 suggests that significant challenges remain with respect to communicating the new forest policies if the objectives of PFM are to be achieved. First, villagers as a group are much less well informed than other stakeholders, and their knowledge is often inaccurate. Second, women are less likely than men to have heard of the changes. Third, how PFM will contribute to poverty reduction (a key objective of PFM) is not always clear. Fourth, environmental degradation may not be reduced as much as anticipated , without alternatives sources, villagers often continue to cut trees for charcoal and firewood in the protected forests. Finally, several mismatches in perceptions are identified that could lead to difficulties in implementing PFM. [source]

    Feeding habits of chimpanzees (Pan troglodytes), red-tail monkeys (Cercopithecus ascanius schmidti) and blue monkeys (Cercopithecus mitis stuhlmanii) on figs in Budongo Forest Reserve, Uganda

    AFRICAN JOURNAL OF ECOLOGY, Issue 2 2001
    Mnason Tweheyo
    Abstract Feeding habits of chimpanzees, red-tail and blue monkeys on figs (Ficus) were studied in compartment N3 of Budongo Forest Reserve, western Uganda, from September 1997 to March 1998. The aim was to examine the spatial and temporal foraging habits of chimpanzees, red-tail monkeys and blue monkeys on figs in the forest reserve. Both scan and focal sampling methods were used to assess the foraging habits of the primates. It was found that the primates fed on emerging leaves of Ficus mucuso Ficalho, F. varifolia Warb. and F. exasperata Vahl. They also preferred ripe fruits to emerging, young and unripe fruits. The primates spent 78% of the morning eating fruits and leaves and inhabited fig trees with fruits for about 4 h. Fig trees with ripe fruits attracted larger numbers of primate groups. It is concluded that information on the feeding habits of chimpanzees and monkeys is required in order to have a clear understanding of the social behaviour and pattern of movement of the primates and to assist in predicting the likely impacts of poor forest management, forest degradation and loss of food resources on their populations. Résumé On a étudié les habitudes alimentaires des chimpanzés, des red tails et des cercopithèques à diadème dans les figuiers (Ficus), dans le compartiment N3 de la Réserve Forestière de Budongo, à l'ouest de l'Ouganda, de septembre 1997 à mars 1998. Le but était d'examiner les habitudes alimentaires, dans l'espace et dans le temps, des chimpanzés, des red tails et des cercopithèques à diadème, dans les figuiers de la réserve forestière. On a utilisé les méthodes par scanner et par échantillonnage focal pour évaluer les habitudes alimentaires des primates. On a découvert que les primates se nourrissaient des jeunes feuilles de Ficus mucoso Ficalho, de F.varifolia Warb et de F.exasperata Vahl. Ils préféraient aussi les fruits mûrs aux fruits verts. Les primates passaient 78% de la matinée à manger des fruits et des feuilles et restaient environ 4 heures dans les figuiers qui avaient des fruits. Les figuiers dont les fruits étaient mûrs attiraient un plus grand nombre de groupes de primates. On en a conclu qu'il était nécessaire d'avoir des informations sur les habitudes alimentaires des chimpanzés et des singes pour bien comprendre le comportement social et schéma de déplacement des primates et pour aider à prévoir les impacts éventuels d'une piètre gestion forestière, de la dégradation de la forêt et de la disparition des ressources alimentaires sur leurs populations. [source]