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Conservation Potential (conservation + potential)

Distribution by Scientific Domains

Life Sciences	85%

Selected Abstracts

The Potential for Species Conservation in Tropical Secondary Forests

CONSERVATION BIOLOGY, Issue 6 2009
ROBIN L. CHAZDON
especialización de hábitat; biodiversidad forestal; bosque secundario; bosque tropical; sucesión Abstract:,In the wake of widespread loss of old-growth forests throughout the tropics, secondary forests will likely play a growing role in the conservation of forest biodiversity. We considered a complex hierarchy of factors that interact in space and time to determine the conservation potential of tropical secondary forests. Beyond the characteristics of local forest patches, spatial and temporal landscape dynamics influence the establishment, species composition, and persistence of secondary forests. Prospects for conservation of old-growth species in secondary forests are maximized in regions where the ratio of secondary to old-growth forest area is relatively low, older secondary forests have persisted, anthropogenic disturbance after abandonment is relatively low, seed-dispersing fauna are present, and old-growth forests are close to abandoned sites. The conservation value of a secondary forest is expected to increase over time, as species arriving from remaining old-growth forest patches accumulate. Many studies are poorly replicated, which limits robust assessments of the number and abundance of old-growth species present in secondary forests. Older secondary forests are not often studied and few long-term studies are conducted in secondary forests. Available data indicate that both old-growth and second-growth forests are important to the persistence of forest species in tropical, human-modified landscapes. Resumen:,A raíz de la pérdida generalizada de los bosques maduros en el trópico, los bosques secundarios probablemente jugarán un mayor papel en la conservación de la biodiversidad forestal. Consideramos una jerarquía compleja de factores que interactúan en el espacio y tiempo para determinar el potencial de conservación de los bosques tropicales secundarios. Más allá de las características de los fragmentos de bosque locales, la dinámica espacial y temporal del paisaje influye en el establecimiento, la composición de especies y la persistencia de bosques secundarios. Los prospectos para la conservación de especies primarias en los bosques secundarios se maximizan en regiones donde la proporción de superficie de bosque maduro-bosque secundario es relativamente baja, los bosques secundarios más viejos han persistido, la perturbación antropogénica después del abandono es relativamente baja, hay presencia de fauna dispersora de semillas y donde hay bosques primarios cerca de sitios abandonados. Se espera que el valor de conservación de un bosque secundario incremente en el tiempo, a medida que se acumulan especies provenientes de los fragmentos de bosque primario remanentes. Muchos estudios están pobremente replicados, lo que impide evaluaciones robustas del número y abundancia de especies primarias presentes en bosques secundarios. Los bosques secundarios más viejos generalmente no son estudiados y son pocos los estudios a largo plazo en bosques secundarios. Los datos disponibles indican que tanto los bosques primarios como los secundarios son importantes para la persistencia de especies forestales en paisajes tropicales modificados por humanos. [source]

Targeting Conservation Action through Assessment of Protection and Exurban Threats

CONSERVATION BIOLOGY, Issue 6 2003
DAVID M. THEOBALD
I developed a methodology to assess the level of threat to conservation of biodiversity to help guide conservation action. This method incorporates socioeconomic indicators of risk, including developed and roaded areas, and measures the proportion of conservation lands affected by developed areas. In addition, I developed a metric called conservation potential to measure the degree of fragmentation of patches caused by development. As an illustration I applied this methodology to Colorado (U.S.A.). Protection levels were determined by examining land ownership, resulting in protected lands (status levels 1 and 2) and unprotected lands (status levels 3 and 4). Areas were considered threatened (at risk) if a land-cover patch had >20% roaded area, >15% developed area, or was highly fragmented. Although 24 of 43 natural land-cover types were unprotected (49% of the state), 9 additional types were threatened. Combining conservation-status protection levels with patterns of threat targets the geographic area where conservation action is needed, provides a way to determine where so-called protected areas are at risk, and allows conservation strategies to be better refined. Resumen: Las evaluaciones de biodiversidad a nivel de paisaje se esfuerzan por proporcionar información para la planificación del uso del suelo y actividades de conservación mediante datos sobre áreas de alto valor de biodiversidad y bajo estatus de protección. Desarrollé una metodología para evaluar el nivel de amenaza para la conservación de la biodiversidad para ayudar a guiar acciones de conservación. Este método incorpora indicadores socioeconómicos de riesgo, incluyendo áreas desarrolladas y con caminos, y mide la proporción de tierras de conservación afectadas por áreas desarrolladas. Adicionalmente, desarrollé una medida llamada potencial de conservación para cuantificar el grado de fragmentación debido al desarrollo. Como un ejemplo, apliqué esta metodología a Colorado (E. U. A). Los niveles de protección se determinaron examinando la propiedad, resultando en tierras protegidas (niveles 1 y 2) y no protegidas (niveles 3 y 4). Las áreas se consideraron amenazadas (en riesgo) si tenían >20% de su superficie con caminos, >15% del área desarrollada o si estaban muy fragmentadas. Aunque 24 de los 43 tipos de cobertura natural no estaban protegidos (49% del estado), 9 más estaban amenazados. La combinación de estatus de conservación y niveles de protección con patrones de amenazas identifica al área geográfica donde se requieren acciones de conservación, proporciona una forma de examinar donde están en riesgo las llamadas áreas protegidas y permite que las estrategias de conservación sean mejor ajustadas. [source]

Spontaneous succession in limestone quarries as an effective restoration tool for endangered arthropods and plants

JOURNAL OF APPLIED ECOLOGY, Issue 1 2010
Robert Tropek
Summary 1. The view of post-mining sites is rapidly changing among ecologists and conservationists, as sensitive restoration using spontaneous succession may turn such sites into biodiversity refuges in human-exploited regions. However, technical reclamation, consisting of covering the sites by topsoil, sowing fast-growing herb mixtures and planting trees, is still commonly adopted. Until now, no multi-taxa study has compared technically reclaimed sites and sites left with spontaneous succession. 2. We sampled communities of vascular plants and 10 arthropod groups in technically reclaimed and spontaneously restored plots in limestone quarries in the Bohemian Karst, Czech Republic. For comparison, we used paired t -tests and multivariate methods, emphasizing red-list status and habitat specialization of individual species. 3. We recorded 692 species of target taxa, with a high proportion of red-listed (10%) and xeric specialist (14%) species, corroborating the great conservation potential of the quarries. 4. Spontaneously restored post-mining sites did not differ in species richness from the technical reclaimed sites but they supported more rare species. The microhabitat cover of leaf litter, herbs and moss, were all directly influenced by the addition of topsoil during reclamation. 5.Synthesis and applications. Our results show that the high conservation potential of limestone quarries could be realized by allowing succession to progress spontaneously with minimal intervention. Given the threat to semi-natural sparsely vegetated habitats in many regions, active restoration measures at post-mining sites should be limited to maintenance of early successional stages, instead of acceleration of succession. [source]

Internal heat integration , the key to an energy-conserving distillation column,

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 2-3 2003
Z Olujic
Abstract This paper illustrates the thermal energy conservation potential of the so-called heat integrated distillation column (HIDiC), which combines advantages of direct vapour recompression and diabatic operation at half of the normal column height. In a typical close boiling mixture separation, compared with a column utilising the usual vapour recompression scheme, HIDiC halved the consumption of exergy at approximately the same capital cost, indicating a strikingly short pay-off time. The complexities of integrating the heat transfer equipment in the stripping section with proven gas/liquid contacting devices, which may work adversely to practical implementation of HIDiC concept, are also addressed. © 2003 Society of Chemical Industry [source]

Old growth and secondary forest site occupancy by nocturnal birds in a neotropical landscape

ANIMAL CONSERVATION, Issue 1 2010
M. Sberze
Abstract High rates of old growth (OG) forest destruction and difficult farming conditions result in increasing cover of secondary forests (SF) in the Amazon. In this setting, it is opportune to ask which animals use newly available SF and which stay restricted to OG. This study presents a comparison of SF and OG site occupancy by nocturnal birds in terra firme forests of the Amazon Guianan shield, north of Manaus, Brazil. We tested species-specific occupancy predictions for two owls (Lophostrix cristata/Glaucidium hardyi), two potoos (Nyctibius leucopterus/Nyctibius griseus) and two nightjars (Caprimulgus nigrescens/Nyctidromus albicollis). For each pair, we predicted that one species would have higher occupancy in OG while the other would either be indifferent to forest type or favor SF sites. Data were collected in 30 OG and 24 SF sites with monthly samples from December 2007 to December 2008. Our analytic approach accounts for the possibility of detection failure and for spatial autocorrelation in occupancy, thus leading to strong inferences about changes in occupancy between forest types and between species. Nocturnal bird richness and community composition were indistinguishable between OG and SF sites. Owls were relatively indifferent to forest type. Potoos followed the a priori predictions, and one of the nightjars (C. nigrescens) favored SF instead of OG as predicted. Only one species, Nyctib. leucopterus, clearly favored OG. The landscape context of our SF study sites, surrounded by a vast expanse of continuous OG forest, partially explains the resemblance between SF and OG fauna but leaves unexplained the higher occupancy for SF than OG sites for several study species. The causal explanation of high SF occupancy remains an open question, but the result itself motivates further comparisons for other groups, as well as recognition of the conservation potential of SF. [source]

Objectives, criteria and methods for using molecular genetic data in priority setting for conservation of animal genetic resources

ANIMAL GENETICS, Issue 2010
P. J. Boettcher
Summary The genetic diversity of the world's livestock populations is decreasing, both within and across breeds. A wide variety of factors has contributed to the loss, replacement or genetic dilution of many local breeds. Genetic variability within the more common commercial breeds has been greatly decreased by selectively intense breeding programmes. Conservation of livestock genetic variability is thus important, especially when considering possible future changes in production environments. The world has more than 7500 livestock breeds and conservation of all of them is not feasible. Therefore, prioritization is needed. The objective of this article is to review the state of the art in approaches for prioritization of breeds for conservation, particularly those approaches that consider molecular genetic information, and to identify any shortcomings that may restrict their application. The Weitzman method was among the first and most well-known approaches for utilization of molecular genetic information in conservation prioritization. This approach balances diversity and extinction probability to yield an objective measure of conservation potential. However, this approach was designed for decision making across species and measures diversity as distinctiveness. For livestock, prioritization will most commonly be performed among breeds within species, so alternatives that measure diversity as co-ancestry (i.e. also within-breed variability) have been proposed. Although these methods are technically sound, their application has generally been limited to research studies; most existing conservation programmes have effectively primarily based decisions on extinction risk. The development of user-friendly software incorporating these approaches may increase their rate of utilization. [source]

Temporal variability in fish larval supply to Malindi Marine Park, coastal Kenya

AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue S1 2009
Boaz Kaunda-Arara
Abstract 1.Larval supply to reef sites influences adult population structure, reef connectivity and conservation potential of marine reserves, but few studies have examined this topic in the Western Indian Ocean (WIO). 2.Fish larval supply to Malindi Marine Park in Kenya was studied using light-traps for a period extending from March 2005 to June 2006. The traps caught pre-settlement fish larvae at two sites spread across the park. Catch rates (number trap,1night,1) were used to represent larval abundance and to test the influence of seasonality and habitat characteristics on larval abundance in the park. 3.Thirty-three species of reef fish larvae in 15 families were sampled. Larval supply to the park was more diverse during the north-east monsoon season (30 species) than in the south-east monsoon season (15 species), with inter-annual variability in abundance. Higher catch rates of larvae occurred in the north-east monsoon month of March in both 2005 and 2006 and the inter-monsoon month of September 2005. 4.Family-specific temporal variation in larval abundance showed dominance of the families Apogonidae and Caesionidae in the park, with higher abundance during the north-east monsoon months. A few families (e.g. Canthigasteridae) showed dominance during the south-east monsoon season. Regression and rank Spearman correlation analyses indicated positive correlation of chlorophyll-a with larval supply while water depth had significant negative correlation with abundance of the Apogonidae and Caesionidae. 5.On a short-term temporal scale larval abundance in the park was highly correlated with the new moon lunar phase more than the full moon. However, on a long-term scale (16 months) larval supply to the park was significant only over a 2-month period and was correlated with environmental productivity more than ambient temperature. These results are useful in understanding the role of larval supply in structuring adult fish populations and the factors that force larval flux at reef sites. Copyright © 2009 John Wiley & Sons, Ltd. [source]