EVOLUTION, Issue 1 2006
Robert H. Kaplan
Abstract Variation in fitness generated by differences in functional performance can often be traced to morphological variation among individuals within natural populations. However, morphological variation itself is strongly influenced by environmental factors (e.g., temperature) and maternal effects (e.g., variation in egg size). Understanding the full ecological context of individual variation and natural selection therefore requires an integrated view of how the interaction between the environment and development structures differences in morphology, performance, and fitness. Here we use naturally occurring environmental and maternal variation in the frog Bombina orientalis in South Korea to show that ovum size, average temperature, and variance in temperature during the early developmental period affect body sizes, shapes, locomotor performance, and ultimately the probability of an individual surviving interspecific predation in predictable but nonadditive ways. Specifically, environmental variability can significantly change the relationship between maternal investment in offspring and offspring fitness so that increased maternal investment can actually negatively affect offspring over a broad range of environments. Integrating environmental variation and developmental processes into traditional approaches of studying phenotypic variation and natural selection is likely to provide a more complete picture of the ecological context of evolutionary change. [source]

SEAWEED INVASIONS: A SYNTHESIS OF ECOLOGICAL, ECONOMIC AND LEGAL IMPERATIVES

JOURNAL OF PHYCOLOGY, Issue 2 2010
Michael H. Graham
No abstract is available for this article. [source]

An Ecological and Economic Assessment of the Nontimber Forest Product Gaharu Wood in Gunung Palung National Park, West Kalimantan, Indonesia

CONSERVATION BIOLOGY, Issue 6 2001
Gary D. Paoli
We studied the demographic effect and economic returns of harvesting aromatic gaharu wood from fungus-infected trees of Aquilaria malaccensis Lam. at Gunung Palung National Park, Indonesia, to evaluate the management potential of gaharu wood. Aquilaria malaccensis trees openface> 20 cm in diameter occurred at low preharvest densities (0.16,0.32 ha) but were distributed across five of six forest types surveyed. During a recent harvest, 75% of trees were felled, with harvest intensities ranging from 50% to 100% among forest types. Overall, 50% of trees contained gaharu wood, but trees at higher elevations contained gaharu wood more frequently ( 73%) than trees at lower elevation (27%). The mean density of regeneration ( juveniles> 15 cm in height) near adult trees (3,7 m away) was 0.2/m2, 200 times greater than at random in the forest (10/ha), but long-term data on growth and survivorship are needed to determine whether regeneration is sufficient for population recovery. Gaharu wood extraction from Gunung Palung was very profitable for collectors, generating an estimated gross financial return per day of US $8.80, triple the mean village wage. Yet, the estimated sustainable harvest of gaharu wood at natural tree densities generates a mean net present value of only $10.83/ha, much lower than that of commercial timber harvesting, the dominant forest use in Kalimantan. Returns per unit area could be improved substantially, however, by implementing known silvicultural methods to increase tree densities, increase the proportion of trees that produce gaharu wood, and shorten the time interval between successive harvests. The economic potential of gaharu wood is unusual among nontimber forest products and justifies experimental trials to develop small-scale cultivation methods. Resumen: Datos ecológicos y económicos son esenciales para la identificación de productos forestales no maderables tropicales con potencial para la extracción sostenible y rentable en un sistema bajo manejo. Estudiamos el efecto demográfico y los beneficios económicos de la cosecha de la madera aromática gaharu de árboles de Aquilaria malaccenis Lam infectados por hongos en el Parque Nacional Gunung Palung Indonesia para evaluar el potencial de manejo de la madera. Arboles de Aquilaria malaccenis> 20 cm de diámetro ocurrieron en bajas densidades precosecha (0.16,0.32 ha,1) pero se distribuyeron en cinco de los seis tipos de bosque muestreados. Durante una cosecha reciente, 75% de los árboles fueron cortados, con intensidades de cosecha entre 50 y 100% en los tipos de bosque. En conjunto, 50% de los árboles contenían madera gaharu, pero árboles de elevaciones mayores contenían madera gaharu más frecuentemente ( 73%) que árboles de elevaciones menores (27%). La densidad promedio de regeneración ( juveniles> 15 cm de altura) cerca de árboles adultos (de 3 a 7 m de distancia) fue de 0.2 m,2, 200 veces mayor que en el bosque (10 ha,1), pero se requieren datos a largo plazo sobre el crecimiento y la supervivencia para determinar si la regeneración es suficiente para la recuperación de la población. La extracción de madera gaharu de Gunung Palung fue muy redituable, generando un rendimiento financiero bruto estimado en US $8.80 diarios, el triple del salario promedio en la zona. Sin embargo, la cosecha sostenible estimada de madera gaharu en densidades naturales de árboles genera un valor presente neto de sólo $10.83 ha,1, mucho menor que el de la cosecha comercial de madera, uso dominante del bosque en Kalimantan. Sin embargo, los rendimientos por unidad de área podrían mejorar sustancialmente mediante la instrumentación de métodos silviculturales para incrementar la densidad de árboles, incrementar la proporción de árboles que producen madera gaharu y reducir el intervalo de tiempo entre cosechas sucesivas. El potencial económico de la madera gaharu es poco usual entre los productos forestales no maderables y justifica la experimentación para desarrollar métodos de cultivo en pequeña escala. [source]

Preference and performance of the hyperparasitoid Syrphophagus aphidivorus (Hymenoptera: Encyrtidae): fitness consequences of selecting hosts in live aphids or aphid mummies

ECOLOGICAL ENTOMOLOGY, Issue 6 2004
R. Buitenhuis
Abstract., 1.,Theoretical models predict that ovipositional decisions of parasitoid females should lead to the selection of the most profitable host for parasitoid development. Most parasitoid species have evolved specific adaptations to exploit a single host stage. However, females of the aphid hyperparasitoid Syrphophagous aphidivorus (Mayr) (Hymenoptera: Encyrtidae) display a unique and atypical oviposition behaviour by attacking either primary parasitoid larvae in live aphids, or parasitoid pupae in dead, mummified aphids. 2.,In the laboratory, the correlation between host suitability and host preference of S. aphidivorus on the host Aphidius nigripes Ashmead parasitising the aphid Macrosiphum euphorbiae (Thomas) was investigated. 3.,The relative suitability of the two host stages was determined by measuring hyperparasitoid fitness parameters (survival, development time, fecundity, sex ratio, and adult size of progeny), and calculating the intrinsic rate of population increase (rm). Host preference by S. aphidivorus females and the influence of aphid defence behaviour on host selection was also examined. 4.,Hyperparasitoid offspring performance was highest when developing from hosts in aphid mummies and females consistently preferred this host to hosts in parasitised aphids. Although aphid defensive behaviour may influence host selection, it was not a determining factor. Ecological and evolutionary processes that might have led to dual oviposition behaviour in S. aphidivorus are discussed. [source]

Ecological and evolutionary consequences of niche construction for its agent

ECOLOGY LETTERS, Issue 10 2008
Grigoris Kylafis
Abstract Niche construction can generate ecological and evolutionary feedbacks that have been underinvestigated so far. We present an eco-evolutionary model that incorporates the process of niche construction to reveal its effects on the ecology and evolution of the niche-constructing agent. We consider a simple plant,soil nutrient ecosystem in which plants have the ability to increase the input of inorganic nutrient as an example of positive niche construction. On an ecological time scale, the model shows that niche construction allows the persistence of plants under infertile soil conditions that would otherwise lead to their extinction. This expansion of plants' niche, however, requires a high enough rate of niche construction and a high enough initial plant biomass to fuel the positive ecological feedback between plants and their soil environment. On an evolutionary time scale, we consider that the rates of niche construction and nutrient uptake coevolve in plants while a trade-off constrains their values. Different evolutionary outcomes are possible depending on the shape of the trade-off. We show that niche construction results in an evolutionary feedback between plants and their soil environment such that plants partially regulate soil nutrient content. The direct benefit accruing to plants, however, plays a crucial role in the evolutionary advantage of niche construction. [source]

Life as an endodontic pathogen

ENDODONTIC TOPICS, Issue 1 2003
Ecological differences between the untreated, root-filled root canals
This review describes the type of microbial flora in the untreated root canal and the root-filled canal with persistent infection. Recent contributions of molecular methods of microbial identification are outlined along with a discussion of advantages and limitations of these methods. Ecological and environmental factors are the prime reasons for differences in the microbial flora in these distinct habitats. Shared phenotypic traits and an ability to respond to the modified environment select for the species that establish a persistent root canal infection. [source]

Ecological and socio-economic impacts of invasive water hyacinth (Eichhornia crassipes): a review

FRESHWATER BIOLOGY, Issue 2 2010
A. M. VILLAMAGNA
Summary 1.,Water hyacinth (Eichhornia crassipes) is one of the world's most invasive aquatic plants and is known to cause significant ecological and socio-economic effects. 2.,Water hyacinth can alter water clarity and decrease phytoplankton production, dissolved oxygen, nitrogen, phosphorous, heavy metals and concentrations of other contaminants. 3.,The effects of water hyacinth on ecological communities appear to be largely nonlinear. Abundance and diversity of aquatic invertebrates generally increase in response to increased habitat heterogeneity and structural complexity provided by water hyacinth but decrease due to decreased phytoplankton (food) availability. 4.,Effects of water hyacinth on fish are largely dependent on original community composition and food-web structure. A more diverse and abundant epiphytic invertebrate community may increase fish abundance and diversity, but a decrease in phytoplankton may decrease dissolved oxygen concentrations and planktivorous fish abundance, subsequently affecting higher trophic levels. 5.,Little is known about the effects of water hyacinth on waterbird communities; however, increases in macroinvertebrate and fish abundance and diversity suggest a potentially positive interaction with waterbirds when water hyacinth is at moderate density. 6.,The socio-economic effects of water hyacinth are dependent on the extent of the invasion, the uses of the impacted waterbody, control methods and the response to control efforts. Ecosystem-level research programmes that simultaneously monitor the effects of water hyacinth on multiple trophic-levels are needed to further our understanding of invasive species. [source]

Study Design for Assessing Species Environment Relationships and Developing Indicator Systems for Ecological Changesin Floodplains , The Approach of the RIVA Project

INTERNATIONAL REVIEW OF HYDROBIOLOGY, Issue 4 2006
Klaus Henle
Abstract In this article the study design and data sampling of the RIVA project , "Development and Testing of a Robust Indicator System for Ecological Changes in Floodplain Systems" , are described. The project was set up to improve existing approaches to study species environment relationships as a basis for the development of indicator systems and predictive models. Periodically flooded grassland was used as a model system. It is agriculturally used at a level of intermediate intensity and is the major habitat type along the Middle Elbe, Germany. We chose a main study area to analyse species environment relationships and two reference sites for testing the transferability of the results. Using a stratified random sampling scheme, we distributed 36 study plots across the main study site and 12 plots each within the reference sites. In each of the study plots, hydrological and soil variables were measured and plants, molluscs, and carabid beetles were sampled. Hoverflies were collected on a subset of the sampling plots. A brief summary of first results is then provided. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

The Metamorphoses of Agrarian Capitalism

JOURNAL OF AGRARIAN CHANGE, Issue 1 2002
Jairus Banaji
Book reviewed in this article: Daniel Thorner (ed.), Ecological and Agrarian Regions of South Asia circa 1930 Daniel Thorner's agrarian atlas of India, fully prepared for the press by 1965, was belatedly published two decades later thanks to the untiring efforts of Alice Thorner. The heart of the atlas consists of a series of descriptions written by the historian Chen Han-seng to illustrate his division of the subcontinent into 21 agrarian regions. The review begins by describing Chen's regionalization and conveying some sense of the quality of his descriptions of individual regions. It then raises analytical issues related to Chen's understanding of agrarian capitalism and his reluctance to characterize developments in the late colonial countryside in terms of the growth of capitalism. The conclusion contrasts two conceptions of agrarian capitalism, rejecting the idea of a historical prototype. [source]

Ecological, environmental and socioeconomic aspects of the Lake Victoria's introduced Nile perch fishery in relation to the native fisheries and the species culture potential: lessons to learn

AFRICAN JOURNAL OF ECOLOGY, Issue 2 2007
John S. Balirwa
Abstract Inland fishery ecosystems in Africa are characterized by patterns of overexploitation, environmental degradation and exotic species introductions. Ecological complexity and diversity of aquatic habitats dictate that fishes in general are not evenly distributed in a water body. However, fisheries management regimes tend to ignore this basic principle, assume generalized conditions in a water body, and focus more on ,desired' objectives such as maximizing catch. The result is to disregard fish habitat boundaries and anthropogenic influences from the catchment that influence fish production. Overexploitation and environmental degradation disrupt sustainable socioeconomic benefits from the fisheries, create uncertainty among investors, but leave some managers calling for more information with the expectation that the fisheries will recover with time. Open access to the fisheries and full control of fishing effort remain challenges for managers. Exotic species introductions and fish farming can increase production, but such interventions require firm commitment to sound ecological principles and strict enforcement of recommended conservation and co-management measures in capture fisheries. The general tendency to downplay fishing effort issues, other ecosystem values and functions or rely on temperate fisheries models until a new cycle of overexploitation emerges, characterizes many management patterns in inland fisheries. Aquaculture is not an option to challenges in capture fisheries management. Aquaculture should be developed to increase fish production but even this practice may have negative environmental impacts depending on practice and scale. Decades of information on Lake Victoria fisheries trends and aquaculture development did not stop the collapse of native fisheries. The successfully introduced Nile perch (Lates niloticus) has shown signs of overexploitation and aquaculture has again been considered as the option. By reviewing significant trends associated with Nile perch and its feasibility in aquaculture this paper uses Lake Victoria to illustrate ,special interest management' targeting selected species of fish rather than the fisheries. Résumé Les écosystèmes africains où se pratique la pêche intérieure se caractérisent par des schémas de surexploitation, de dégradation environnementale et d'introductions d'espèces exotiques. La complexité et la diversité des habitats aquatiques impliquent que les poissons ne sont, en général, pas distribués de façon uniforme dans une entité aquatique. Pourtant, les divers régimes de gestion des pêcheries tendent à ignorer ce principe élémentaire, présument de conditions uniformes dans une entité aquatique et visent plus les objectifs « souhaités », comme des prises maximales. Le résultat, c'est que l'on ne tient pas compte des limites de l'habitat des poissons et des impacts anthropiques du bassin versant qui influencent la production de poisson. La surexploitation et la dégradation de l'environnement compromettent les bénéfices socio-économiques durables de la pêche, engendrent l'incertitude parmi les investisseurs et font que certains gestionnaires sollicitent plus d'informations dans l'attente que la pêche se redresse avec le temps. L'accès libre à la pêche et le contrôle total des efforts de pêche restent de vrais défis pour les gestionnaires. Les introductions d'espèces exotiques et les fermes piscicoles peuvent augmenter la production, mais ces interventions exigent un engagement solide vis-à-vis des principes écologiques responsables et l'application stricte des mesures de conservation et de co-gestion recommandées pour la pêche. La tendance générale à minimiser les problèmes des efforts de pêche et les autres valeurs et fonctions de l'écosystème, ou à se baser sur des modèles de pêche tempérés jusqu'à ce qu'un nouveau cycle de surexploitation émerge, caractérise de nombreux schémas de gestion de pêche intérieure. L'aquaculture n'est pas une option pour les défis auxquels fait face la gestion de la pêche. L'aquaculture devrait être développée pour augmenter la production de poisson, mais même cette pratique peut avoir des impacts environnementaux négatifs dus à l'échelle et à la façon dont on la pratique. Des décennies d'informations sur les tendances de la pêche et le développement de l'aquaculture dans le lac Victoria n'ont pas empêché l'effondrement de la pêche originale. La perche du Nil (Lates niloticus), introduite avec succès montre des signes de surexploitation et l'aquaculture a de nouveau été envisagée. En passant en revue les tendances significatives liées à la perche du Nil et la faisabilité de son aquaculture, cet article se sert du lac Victoria pour illustrer la « gestion d'intérêt spécial » qui vise des espèces de poissons sélectionnées plutôt que la pêche. [source]

Building Bridges: The Transdisciplinary Study of Craving From the Animal Laboratory to the Lamppost

ALCOHOLISM, Issue 2 2004
Peter M. Monti
Abstract: This article represents the proceedings of a symposium at the 2003 Research Society on Alcoholism meeting in Ft. Lauderdale, Florida, organized and chaired by Peter M. Monti. The presentations and presenters were (1) Alcohol Seeking and Self-Administration in Rats: The Role of Serotonin Activity, by Cristine L. Czachowski; (2) Assessing Binge Drinking in Monkeys, by Kathleen A. Grant; (3) Craving and the Perception of Time, by Michael Sayette; (4) Ecological and Laboratory Assessment of Alcohol Urges and Drinking: Effects of Naltrexone, by Peter M. Monti; and (5) Discussion, by Damaris J. Rohsenow. [source]

Ecological, morphological and genetic divergence of sympatric North Atlantic killer whale populations

MOLECULAR ECOLOGY, Issue 24 2009
ANDREW D. FOOTE
Abstract Ecological divergence has a central role in speciation and is therefore an important source of biodiversity. Studying the micro-evolutionary processes of ecological diversification at its early stages provides an opportunity for investigating the causative mechanisms and ecological conditions promoting divergence. Here we use morphological traits, nitrogen stable isotope ratios and tooth wear to characterize two disparate types of North Atlantic killer whale. We find a highly specialist type, which reaches up to 8.5 m in length and a generalist type which reaches up to 6.6 m in length. There is a single fixed genetic difference in the mtDNA control region between these types, indicating integrity of groupings and a shallow divergence. Phylogenetic analysis indicates this divergence is independent of similar ecological divergences in the Pacific and Antarctic. Niche-width in the generalist type is more strongly influenced by between-individual variation rather than within-individual variation in the composition of the diet. This first step to divergent specialization on different ecological resources provides a rare example of the ecological conditions at the early stages of adaptive radiation. [source]

Spread of a Terrestrial Tradition in an Arboreal Primate

AMERICAN ANTHROPOLOGIST, Issue 2 2009
Fernanda P. Tabacow
ABSTRACT We present data on the spread of terrestrial activities in one group of wild northern muriqui monkeys (Brachyteles hypoxanthus). Both males and females consumed fruit, drank, rested, traveled, and socialized terrestrially, but proportionately more males spent significantly more of their time on the ground than females, and females were more likely to engage in terrestrial activities when accompanied by males than when by themselves. Terrestrial activities occurred in both open and closed habitats where arboreal substrates were available and utilized by other individuals engaged in similar activities. Ecological and demographic factors may have stimulated the muriquis' vertical niche expansion, but increases in the frequency and diversity of terrestrial activities, the high proportion of group members that engage in terrestriality, and its diffusion along male-biased social bonds are consistent with the development of a local terrestrial tradition similar to other types of traditions described in other primates. [Key words: terrestriality, ecology, predation, tradition] [source]

Ecological and genetic notes on Lindsaea digitata (Lindsaeaceae), a new fern species from western Amazonia

NORDIC JOURNAL OF BOTANY, Issue 3-4 2007
Samuli Lehtonen
Morphological, ecological and genetic evidence have revealed the existence of two sympatric species in what has previously been recognised as Lindsaea divaricata Klotzsch. The new species, Lindsaea digitata Lehtonen & Tuomisto, is described here, and its ecological and genetic differences from the apparently closely related L. divaricata are documented. [source]

Ecological and evolutionary trends in wetlands: Evidence from seeds and seed banks in New South Wales, Australia and New Jersey, USA

PLANT SPECIES BIOLOGY, Issue 2 2000
Mary A. Leck
Abstract Aquatic plants include a variety of life forms and functional groups that are adapted to diverse wetland habitats. Both similarities and differences in seed and seed-bank characteristics were discovered in comparisons of Australian (New South Wales) temporary upland wetlands with a North American (New Jersey) tidal freshwater marsh having both natural and constructed wetlands. In the former, flooding and drying are unpredictable and in the latter water levels vary diurnally and substrate is constantly moist. The hydrologic regimen provides the overriding selective force, with climate an important second factor. Other factors related to water level, such as oxygen availability, temperature and light, vary spatially and temporally, influencing germination processes, germination rates and seedling establishment. Seed and seed-bank characteristics (size, desiccation and inundation tolerance, germination cues and seed-bank longevity and depletion) differ, with the Australian temporary wetland being more similar to the small-seeded persistent seed bank of the constructed wetland site than to the natural tidal freshwater site with its larger seeds, transient seed bank and seasonal spring germination. Some non-spring germination can occur in the tidal constructed wetland if the soil is disturbed. In contrast, seeds in the temporary Australian wetlands germinated in response to wet/dry cycles rather than to season. Functional groups (e.g. submerged, amphibious) are more diverse in the Australian temporary wetlands, where all species tolerate drying. We suggest that the amphibious zone, with its hydrologic gradient, is the site of selection pressure determining establishment of wetland plants from seed. In this zone, multiple selective factors vary spatially and temporally. [source]

Book review: Behavioral, Ecological, and Life History Perspectives

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2008
Kevin L. Kuykendall
No abstract is available for this article. [source]

Mitochondrial Cytochrome b mRNA Editing in Dinoflagellates: Possible Ecological and Evolutionary Associations?

THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 6 2005
HUAN ZHANG
Abstract. To verify the hypothesis that mt mRNA editing is widespread in dinoflagellates, we analyzed cytochrome b (cob) mRNA editing for six species representing distinct ecotypes and taxonomic classes of Dinophyceae. Editing is detected in all, which is similar to the three other species studied previously in that edited sites appear to aggregate in four clusters and occur predominantly at first and second positions of codons (93%), overwhelmingly involving A,G, U,C, or C,U substitutions with a smaller number of G,C, G,A changes. Comparative analyses on editing characteristics reveal interesting trends related to phylogenetic relatedness and ecological features. Editing density (percentage of nucleotide that is affected by editing) increases from early to derived lineages. Higher editing densities also map to red tide-forming lineages. Furthermore, similarity of location of edited codons (LOE) and the type of nucleotide changes (TOE) in different lineages mirror the taxonomic affinity of the lineages. Phylogenetic trees constructed from LOE and TOE resemble those inferred from cob sequences. The results bolster our earlier hypothesis that cob editing is widespread in dinoflagellates and suggest that density, location, and type of editing may bear yet-to-be-defined evolutionary and ecological significance. [source]

Habitat Fragmentation and Landscape Change: An Ecological and Conservation Synthesis

AUSTRAL ECOLOGY, Issue 4 2007
ROBERT DAVIS
No abstract is available for this article. [source]

Tropical Rain Forests: an Ecological and Biogeographical Comparison

AUSTRAL ECOLOGY, Issue 6 2005
RALF BUCKLEY
No abstract is available for this article. [source]

Evolution of Ecological and Behavioural Diversity: Australian Acacia Thrips as Model Organisms

AUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 2 2005
Myron P Zalucki
No abstract is available for this article. [source]

Ecological and evolutionary components of body size: geographic variation of venomous snakes at the global scale

BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2009
LEVI CARINA TERRIBILE
Biogeographical patterns of animal body size and the environmental and evolutionary mechanisms that may be driving them have been broadly investigated in macroecology, although just barely in ectotherms. We separately studied two snake clades, Viperidae and Elapidae, and used phylogenetic eigenvector regression and ordinary least squares multiple regression methods to perform a global grid-based analysis of the extent at which the patterns of body size (measured for each species as its log10 -transformed maximum body length) of these groups are phylogenetically structured or driven by current environment trends. Phylogenetic relatedness explained 20% of the across-species size variation in Viperidae, and 59% of that of Elapidae, which is a more recent clade. Conversely, when we analysed spatial trends in mean body size values (calculated for each grid-cell as the average size of its extant species), an environmental model including temperature, precipitation, primary productivity (as indicated by the global vegetation index) and topography (range in elevation) explained 37.6% of the variation of Viperidae, but only 4.5% of that of Elapidae. These contrasted responses of body size patterns to current environment gradients are discussed, taking into consideration the dissimilar evolutionary histories of these closely-related groups. Additionally, the results obtained emphasize the importance of the need to start adopting deconstructive approaches in macroecology. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 94,109. [source]

The geometry of coexistence

BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2000
PRIYANGA AMARASEKARE
Understanding the processes that maintain diversity has been the focus of extensive study, yet there is much that has not been integrated into a cohesive framework. First, there is a separation of perspective. Ecological and evolutionary approaches to diversity have progressed in largely parallel directions. Second, there is a separation of emphasis. In both ecology and population genetics, classical theories favour local explanations with emphasis on population dynamics and selection within populations, while contemporary theories favour spatial explanations, with emphasis on population structure and interactions among populations. What is lacking is a comparative approach that evaluates the relative importance of local and spatial processes in maintaining genetic and ecological diversity. I present a framework for diversity maintenance that emphasizes the comparative approach. I use a well-known but little-used mathematical approach, the perturbation theorem for dynamical systems, to identify key points of contact between ecological and population genetic theories of coexistence. These connections provide for a synthesis of several important concepts: population structure (source-sink versus extinction-colonization), spatial heterogeneity (intrinsic versus extrinsic) in fitness and competitive ability, and temporal scales over which local and spatial processes influence diversity. This framework ties together a large and diverse body of theory and data from ecology and population genetics. It yields comparative predictions that can serve as guidelines in biodiversity management. [source]

Diversity, conservation status and threats to native oysters (Ostreidae) around the Atlantic and Caribbean coasts of South America

AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 3 2009
Alvar Carranza
Abstract 1.Despite the extensive literature on the ecology, systematics and culture of oysters worldwide, an assessment of their diversity, distribution and conservation status for the Atlantic and Caribbean coasts (i.e. depth <50 m) of South America is lacking. Such information is crucial because of the increasing coastal development that threatens most nearshore habitats throughout the region. 2.The available information on oysters on Atlantic and Caribbean coasts is reviewed with a focus on identifying regional conservation priorities based on ecological and socio-economic importance, as well as the magnitude of current or potential threats faced by oyster populations. The current status of ,- taxonomy within the Ostreidae was also examined. 3.Ten species of native Ostreidae (plus three introduced species) inhabit the coastal waters of the Atlantic and Caribbean coasts of South America. 4.Oyster species were ranked according to their biological/ecological and socio-economic value and conservation status within 10 distinct ecoregions. Crassostrea gasar in the Eastern Brazil ecoregion, C. rhizophorae in the Central Caribbean ecoregion and Ostrea puelchana in the North Patagonian Gulfs ecoregion should receive the highest priority for immediate conservation action due to extensive loss of mangrove habitat in the two former regions and evidence of decline of one of the most important populations for the latter. The need for a standardized methodology to assess the status of oyster populations throughout the ecoregions is identified. 5.On a local scale, the allocation of territorial use rights for fisheries under a collaborative/voluntary community framework is strongly advocated to fulfil management, conservation and poverty alleviation goals in these developing countries. Copyright © 2008 John Wiley & Sons, Ltd. [source]

The Ecological Future of the North American Bison: Conceiving Long-Term, Large-Scale Conservation of Wildlife

CONSERVATION BIOLOGY, Issue 2 2008
ERIC W. SANDERSON
Bison bison; conservación de especies; Declaración de Vermejo; metas de conservación; representación ecológica Abstract:,Many wide-ranging mammal species have experienced significant declines over the last 200 years; restoring these species will require long-term, large-scale recovery efforts. We highlight 5 attributes of a recent range-wide vision-setting exercise for ecological recovery of the North American bison (Bison bison) that are broadly applicable to other species and restoration targets. The result of the exercise, the "Vermejo Statement" on bison restoration, is explicitly (1) large scale, (2) long term, (3) inclusive, (4) fulfilling of different values, and (5) ambitious. It reads, in part, "Over the next century, the ecological recovery of the North American bison will occur when multiple large herds move freely across extensive landscapes within all major habitats of their historic range, interacting in ecologically significant ways with the fullest possible set of other native species, and inspiring, sustaining and connecting human cultures." We refined the vision into a scorecard that illustrates how individual bison herds can contribute to the vision. We also developed a set of maps and analyzed the current and potential future distributions of bison on the basis of expert assessment. Although more than 500,000 bison exist in North America today, we estimated they occupy <1% of their historical range and in no place express the full range of ecological and social values of previous times. By formulating an inclusive, affirmative, and specific vision through consultation with a wide range of stakeholders, we hope to provide a foundation for conservation of bison, and other wide-ranging species, over the next 100 years. Resumen:,Muchas especies de mamíferos de distribución amplia han experimentado declinaciones significativas durante los últimos 200 años; la restauración de estas especies requerirá esfuerzos de recuperación a largo plazo y a gran escala. Resaltamos 5 atributos de un reciente ejercicio de gran visión para la recuperación ecológica del bisonte de Norte América (Bison bison) que son aplicables en lo general a otras especies y objetivos de restauración. El resultado del ejercicio, la "Declaración de Vermejo", explícitamente es (1) de gran escala, (2) de largo plazo, (3) incluyente, (4) satisfactor de valores diferentes y (5) ambicioso. En parte, establece que "En el próximo siglo, la recuperación ecológica del Bisonte de Norte América ocurrirá cuando múltiples manadas se desplacen libremente en los extensos paisajes de todos los hábitats importantes en su rango de distribución histórica, interactúen de manera significativa ecológicamente con el conjunto más completo de otras especies nativas e inspiren, sostengan y conecten culturas humanas." Refinamos esta visión en una tarjeta de puntuación que ilustra cómo las manadas de bisonte individuales pueden contribuir a la visión. También desarrollamos un conjunto de mapas y analizamos las distribuciones actuales y potencialmente futuras del bisonte con base en la evaluación de expertos. Aunque actualmente existen más de 500,000 bisontes en Norte América, estimamos que ocupan <1% de su distribución histórica y no expresan el rango completo de valores ecológicos y culturales de otros tiempos. Mediante la formulación de una visión incluyente, afirmativa y específica basada en la consulta a una amplia gama de interesados, esperamos proporcionar un fundamento para la conservación del bisonte, y otras especies de distribución amplia, para los próximos 100 años. [source]

Pacific Salmon Extinctions: Quantifying Lost and Remaining Diversity

CONSERVATION BIOLOGY, Issue 4 2007
RICHARD G. GUSTAFSON
biodiversidad; diversidad de salmones; extinción de poblaciones; historia de vida de salmones Abstract:,Widespread population extirpations and the consequent loss of ecological, genetic, and life-history diversity can lead to extinction of evolutionarily significant units (ESUs) and species. We attempted to systematically enumerate extinct Pacific salmon populations and characterize lost ecological, life history, and genetic diversity types among six species of Pacific salmon (Chinook [Oncorhynchus tshawytscha], sockeye [O. nerka], coho [O. kisutch], chum [O. keta], and pink salmon [O. gorbuscha] and steelhead trout [O. mykiss]) from the western contiguous United States. We estimated that, collectively, 29% of nearly 1400 historical populations of these six species have been lost from the Pacific Northwest and California since Euro-American contact. Across all species there was a highly significant difference in the proportion of population extinctions between coastal (0.14 extinct) and interior (0.55 extinct) regions. Sockeye salmon (which typically rely on lacustrine habitats for rearing) and stream-maturing Chinook salmon (which stay in freshwater for many months prior to spawning) had significantly higher proportional population losses than other species and maturation types. Aggregate losses of major ecological, life-history, and genetic biodiversity components across all species were estimated at 33%, 15%, and 27%, respectively. Collectively, we believe these population extirpations represent a loss of between 16% and 30% of all historical ESUs in the study area. On the other hand, over two-thirds of historical Pacific salmon populations in this area persist, and considerable diversity remains at all scales. Because over one-third of the remaining populations belong to threatened or endangered species listed under the U.S. Endangered Species Act, it is apparent that a critical juncture has been reached in efforts to preserve what remains of Pacific salmon diversity. It is also evident that persistence of existing, and evolution of future, diversity will depend on the ability of Pacific salmon to adapt to anthropogenically altered habitats. Resumen:,Las extirpaciones generalizadas de poblaciones y la consecuente pérdida de diversidad ecológica, genética y de historia natural puede llevar a la extinción de unidades evolutivamente significativas (UES) y especies. Intentamos enumerar sistemáticamente a las poblaciones extintas de salmón del Pacífico y caracterizar a los tipos de diversidad ecológica, de historia natural y genética de seis especies de salmón del Pacífico Oncorhynchus tshawytscha, O. nerka, O. kisutch, O. keta, y O. gorbuscha; y trucha O. mykiss en el occidente de Estados Unidos. Estimamos que, colectivamente, se ha perdido a 29% de casi 1400 poblaciones históricas de estas seis especies en el Pacífico Noroeste y California desde la colonización europea. En todas las especies hubo una diferencia altamente significativa en la proporción de extinción de poblaciones entre regiones costeras (0.14 extintas) e interiores (0.55 extintas). O. nerka (que típicamente cría en hábitats lacustres) y O. tshawytscha (que permanece en agua dulce por muchos meses antes del desove) tuvieron pérdidas poblacionales significativamente mayores que las otras especies y tipos de maduración. Se estimó que las pérdidas agregadas de componentes mayores de la biodiversidad ecológica, de historia natural y genética en todas las especies fueron de 33%, 15% y 27%, respectivamente. Colectivamente, consideramos que estas extirpaciones de poblaciones representan una pérdida entre 16% y 30% de todas las UES históricas en el área de estudio. Por otro lado, más de dos tercios de las poblaciones históricas de salmón del Pacífico persisten en esta área, y aun hay considerable diversidad en todas las escalas. Debido a que más de un tercio de las poblaciones restantes pertenecen a especies enlistadas como amenazadas o en peligro en el Acta de Especies en Peligro de E. U. A., es evidente que se ha llegado a una disyuntiva crítica en los esfuerzos para preservar lo que queda de la diversidad de salmón del Pacífico. También es evidente que la persistencia de la diversidad existente, y su futura evolución, dependerá de la habilidad del salmón del Pacífico para adaptarse a hábitats alterados antropogénicamente. [source]

Achieving Integrative, Collaborative Ecosystem Management

CONSERVATION BIOLOGY, Issue 5 2006
HEATHER L. KEOUGH
beneficios sociales y ecológicos; gestión; participación pública; toma de decisiones cooperativa Abstract:,Although numerous principles have been identified as being important for successfully integrating social and ecological factors in collaborative management, few authors have illustrated how these principles are used and why they are effective. On the basis of a review of the ecosystem management and collaboration literature, we identified eight factors important for integrative, collaborative ecosystem management,integrated and balanced goals, inclusive public involvement, stakeholder influence, consensus group approach, collaborative stewardship, monitoring and adaptive management, multidisciplinary data, and economic incentives. We examined four cases of successful ecosystem management to illustrate how the factors were incorporated and discuss the role they played in each case's success. The cases illustrate that balancing social and ecosystem sustainability goals is possible. Collaborative efforts resulted in part from factors aimed at making plans economically feasible and from meaningful stakeholder participation in ongoing management. It also required participation in monitoring programs to ensure stakeholder interests were protected and management efforts were focused on agreed-upon goals. Data collection efforts were not all-inclusive and systematic; rather, they addressed the ecological, economic, and social aspects of key issues as they emerged over time. Economic considerations appear to be broader than simply providing economic incentives; stakeholders seem willing to trade some economic value for recreational or environmental benefits. The cases demonstrate that it is not idealistic to believe integrative, collaborative ecosystem management is possible in field applications. Resumen:,Aunque numerosos principios han sido identificados como importantes para la integración exitosa de factores sociales y ecológicos en la gestión cooperativa, pocos autores han ilustrado como son utilizados estos principios y porque son efectivos. Con base en una revisión de la literatura sobre gestión de ecosistemas y colaboración, identificamos cinco factores,metas integradas y balanceadas, inclusive participación pública, influencia de grupos de interés, estrategia de consenso en el grupo, gestión cooperativa, gestión adaptativa y monitoreo, datos multidisciplinarios e incentivos económicos,que son importantes para la gestión integradora y cooperativa de ecosistemas. Examinamos cuatro casos de gestión exitosa de ecosistemas para ilustrar como fueron incorporados los factores y discutimos el papel que jugaron en el éxito de cada caso. Los casos ilustran que el balance de metas de sustentabilidad social y ecológica es posible. En parte, los esfuerzos cooperativos resultaron de factores orientados a hacer que los planes fueran económicamente viables y de la participación significativa de grupos de interés en la gestión en curso. También se requirió la participación en programas de monitoreo para asegurar que los intereses de los grupos fueran protegidos y los esfuerzos de gestión se enfocaran en las metas acordadas. No todos los esfuerzos de recolecta de datos fueron incluyentes y sistemáticos, más bien, eran dirigidos a los aspectos ecológicos, económicos y sociales de temas clave a medida que emergían. Las consideraciones económicas parecen ser más amplias que simplemente proporcionar incentivos económicos, los grupos de interés parecen dispuestos a cambiar algo de valor económico por beneficios recreativos o ambientales. Los casos demuestran que no es idealista pensar que es posible aplicar la gestión integradora y cooperativa de ecosistemas en el campo. [source]

Conservation of Insect Diversity: a Habitat Approach

CONSERVATION BIOLOGY, Issue 6 2000
Jennifer B. Hughes
To explore the feasibility of basing conservation action on community-level biogeography, we sampled a montane insect community. We addressed three issues: (1) the appropriate scale for sampling insect communities; (2) the association of habitat specialization,perhaps a measure of extinction vulnerability,with other ecological or physical traits; and (3) the correlation of diversity across major insect groups. Using malaise traps in Gunnison County, Colorado, we captured 8847 Diptera (identified to family and morphospecies), 1822 Hymenoptera (identified to morphospecies), and 2107 other insects (identified to order). We sampled in three habitat types,meadow, aspen, and conifer,defined on the basis of the dominant vegetation at the scale of hundreds of meters. Dipteran communities were clearly differentiated by habitat type rather than geographic proximity. This result also holds true for hymenopteran communities. Body size and feeding habits were associated with habitat specialization at the family level. In particular, habitat generalists at the family level,taxa perhaps more likely to survive anthropogenic habitat alteration,tended to be trophic generalists. Dipteran species richness was marginally correlated with hymenopteran species richness and was significantly correlated with the total number of insect orders sampled by site. Because these correlations result from differences in richness among habitat types, insect taxa may be reasonable surrogates for one another when sampling is done across habitat types. In sum, community-wide studies appear to offer a practical way to gather information about the diversity and distribution of little-known taxa. Resumen:No existe ni el tiempo ni los recursos para diseñar planes de conservación para cada especie, particularmente para los taxones poco estudiados, no carismáticas, pero ecológicamente importantes que componen la mayoría de la biodiversidad. Para explorar la factibilidad de basar acciones de conservación en biogegrafía a nivel comunitario, muestreamos una comunidad de insectos de montaña. Evaluamos tres aspectos: (1) la escala adecuada para el muestreo de comunidades de insectos; (2) la asociación de especialización de hábitat,quizá una medida de vulnerabilidad de extinción,con otras características ecológicas o físicas; y (3) la correlación de la diversidad a lo largo de los grupos principales de insectos. Mediante el uso de trampas en el condado Gunnison, en Colorado, capturamos 8847 dípteros (identificados a nivel de familia y morfoespecies), 1822 himenópteros (identificadas hasta morfoespecies) y 2107 otros insectos (identificados a nivel de orden). Muestreamos tres tipos de hábitats,vega, álamos temblones y coníferas,definidos en base a la vegetación dominante a escala de cientos de metros. Las comunidades de dípteros estuvieron claramente diferenciadas por tipos de hábitat y no por la proximidad geográfica. Este resultado también se mantiene para las comunidades de himenópteros. El tamaño del cuerpo y los hábitos alimenticios estuvieron asociados con la especialización del hábitat a nivel de familia. En particular, los generalistas de hábitat a nivel de familia,los taxones que posiblemente tengan mayor probabilidad de sobrevivir alteraciones antropogénicas del hábitat,tendieron a ser generalistas tróficos. La riqueza de las especies de dípteros estuvo marginalmente correlacionada con la riqueza de especies de himenópteros y estuvo significativamente correlacionada con el número total de órdenes de insectos muestreadas por sitio. Debido a que estas correlaciones resultaron de diferencias en la riqueza de especies entre tipos de hábitats, los taxones de insectos podrían ser substitutos mutuos razonables cuando se muestrea entre diferentes tipos de hábitats. En resumen, los estudios a lo largo de comunidades parecen ofrecer una forma práctica de recolectar información sobre la diversidad y distribución de los taxones poco estudiados. [source]

Sustainability quotients and the social footprint

CORPORATE SOCIAL RESPONSIBILITY AND ENVIRONMENTAL MANAGEMENT, Issue 4 2008
Mark W. McElroy
Abstract We argue that most of what passes for mainstream reporting in corporate sustainability management fails to do precisely the one thing it purports to do , which is make it possible for organizations to measure and report on the sustainability of their operations. It fails because of the lack of what the Global Reporting Initiative calls sustainability context, a shortcoming from which it, too, suffers. We suggest that this missing context calls for a new notion of sustainability (the binary perspective), which can be conceptualized in the form of sustainability quotients. We provide specifications for such quotients in ecological and social contexts, and suggest that sustainability is best understood in terms of the impact organizations can have on the carrying capacity of non-financial capital, or what in the social case we call anthro capital. We conclude by introducing a quantitative quotients-based method for measuring and reporting on the social sustainability of an organization, the social footprint method. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment. [source]

From financial to sustainable profit

CORPORATE SOCIAL RESPONSIBILITY AND ENVIRONMENTAL MANAGEMENT, Issue 2 2002
Prof. Jacqueline Cramer
This article explains why sustainable business has caught the spotlight at this particular time. Main drivers are the shift in power relationships between states, firms and households, the emergence of civil regulation and the communication through networks. The implication of this trend towards sustainable business is that firms will consciously need to focus on creating value not only in financial terms, but also in ecological and social terms. The challenge facing the business sector is how to set about meeting these expectations. Firms will need to change not only in themselves, but also in the way they interact with their environment. Copyright © 2002 John Wiley & Sons, Ltd. and ERP Environment [source]

Partitioned Nature, Privileged Knowledge: Community-based Conservation in Tanzania

DEVELOPMENT AND CHANGE, Issue 5 2003
Mara Goldman
Community Based Conservation (CBC) has become the catch,all solution to the social and ecological problems plaguing traditional top,down, protectionist conservation approaches. CBC has been particularly popular throughout Africa as a way to gain local support for wildlife conservation measures that have previously excluded local people and their development needs. This article shows that, despite the rhetoric of devolution and participation associated with new CBC models, conservation planning in Tanzania remains a top,down endeavour, with communities and their specialized socio,ecological knowledge delegated to the margins. In addition to the difficulties associated with the transfer of power from state to community hands, CBC also poses complex challenges to the culture or institution of conservation. Using the example of the Tarangire,Manyara ecosystem, the author shows how local knowledge and the complexities of ecological processes challenge the conventional zone,based conservation models, and argues that the insights of local Maasai knowledge claims could better reflect the ecological and social goals of the new CBC rhetoric. [source]