Translating habitat class to land cover to map area of habitat of terrestrial vertebrates

Area of habitat (AOH) is defined as the “habitat available to a species, that is, habitat within its range” and is calculated by subtracting areas of unsuitable land cover and elevation from the range. The International Union for the Conservation of Nature (IUCN) Habitats Classification Scheme provides information on species habitat associations, and typically unvalidated expert opinion is used to match habitat to land-cover classes, which generates a source of uncertainty in AOH maps. We developed a data-driven method to translate IUCN habitat classes to land cover based on point locality data for 6986 species of terrestrial mammals, birds, amphibians, and reptiles. We extracted the land-cover class at each point locality and matched it to the IUCN habitat class or classes assigned to each species occurring there. Then, we modeled each land-cover class as a function of IUCN habitat with (SSG, using) logistic regression models. The resulting odds ratios were used to assess the strength of the association between each habitat and land-cover class. We then compared the performance of our data-driven model with those from a published translation table based on expert knowledge. We calculated the association between habitat classes and land-cover classes as a continuous variable, but to map AOH as binary presence or absence, it was necessary to apply a threshold of association. This threshold can be chosen by the user according to the required balance between omission and commission errors. Some habitats (e.g., forest and desert) were assigned to land-cover classes with more confidence than others (e.g., wetlands and artificial). The data-driven translation model and expert knowledge performed equally well, but the model provided greater standardization, objectivity, and repeatability. Furthermore, our approach allowed greater flexibility in the use of the results and uncertainty to be quantified. Our model can be modified for regional examinations and different taxonomic groups.     

Distance-based eigenvector maps (DBEM) to analyse metapopulation structure with irregular sampling

Characterizing spatial patterns due to ecological processes is a major issue for analysing and predicting species distributions. Grasping the non-linear nature of population dynamics over networks of discrete suitable sites is here central, as very specific signatures are expected. In the line of promising results from Fourier analysis of metapopulation maps, we found distance-based eigenvector maps (DBEM) to help disentangle the respective signatures of habitat and metapopulation structuring, with the great advantage of being applicable to irregular sampling schemes, a common feature of ecological surveys. A smoothing procedure was required to obtain the distinguishable signatures, and this may be a critical issue for investigating non-contingent and reliable patterns in spatial ecology.     

The Coachella Valley Multiple Species Habitat Conservation Plan: A Decade of Delays

This article describes the history of the Coachella Valley Multiple Species Habitat Conservation Plan (CVMSHCP), in the Riverside County region of Southern California. When this collaborative biodiversity conservation planning process began, in 1994, local participants and supporters had numerous factors working in their favor. Yet, as of April 2007, nearly 13 years had passed without an approved plan. This is a common problem. Many multiple species habitat conservation plans now take more than a decade to complete, and the long duration of these processes often results in negative consequences. The CVMSHCP process became bogged down—despite strong scientific input and many political advantages—due to problematic relationships between the Plan’s local supporters, its municipal signatory parties, and officials from the state and federal wildlife agencies, particularly the regional office of the US Fish and Wildlife Service. This case study demonstrates the crucial importance of institutional structures and relationships, process management, and timeliness in habitat conservation planning. We conclude by offering several related recommendations for future HCP processes.     

The effects of landscape-level disturbance on the composition of Minnesota caddisfly (Insecta: Trichoptera) trophic functional groups: evidence for ecosystem homogenization

Over 300,000 caddisfly specimens representing 249 species were collected from nearly 250 sites throughout Minnesota during 2000 and 2001 to determine the effects of human disturbance on the composition of caddisfly trophic functional groups at the landscape level. Canonical correspondence analysis determined that stream width was the most important variable influencing functional group composition in regions of the state with relatively low disturbance, and that differences in the caddisfly fauna between sizes of streams generally followed trends predicted by the river continuum concept. In regions of the state with moderate disturbance, both stream width and the percentage of disturbed habitat upstream of a site were important variables influencing functional group composition. In highly disturbed regions, no variables corresponded to changes in the composition of caddisfly functional groups. Instead, ecosystems were homogeneous: fine-particle filtering collectors dominated in all sizes of streams. The observed aquatic ecosystem homogenization is attributed mostly to input of fine-particle organic and inorganic sediment from extensive agriculture.     

Rehabilitation of metropolitan beaches by local administrations in Catalonia: new trends in sustainable coastal management

The planning and management of coastal sites in Catalonia has been mainly concerned with rendering beaches functional for mass frequentation. This has caused serious problems for the beaches, including the alteration of dune formation processes and the destruction of beach vegetation and habitats. Municipal capacity to plan and manage beaches is theoretically very limited and relegated to the design of plans related to the maintenance of facilities for beach users. Nonetheless, a singular experience, led by a local council in the metropolitan area of Barcelona demonstrates the crucial role that a local administration can play in achieving a balance between habitat preservation and social use based on sustainable coastal management objectives, in spite of a restrictive legislation.     

Impacts of Urbanization on Stream Habitat and Fish Across Multiple Spatial Scales

We analyzed the relation of the amount and spatial pattern of land cover with stream fish communities, in-stream habitat, and baseflow in 47 small southeastern Wisconsin, USA, watersheds encompassing a gradient of predominantly agricultural to predominantly urban land uses. The amount of connected impervious surface in the watershed was the best measure of urbanization for predicting fish density, species richness, diversity, and index of biotic integrity (IBI) score; bank erosion; and base flow. However, connected imperviousness was not significantly correlated with overall habitat quality for fish. Nonlinear models were developed using quantile regression to predict the maximum possible number of fish species, IBI score, and base flow for a given level of imperviousness. At watershed connected imperviousness levels less than about 8%, all three variables could have high values, whereas at connected imperviousness levels greater than 12% their values were inevitably low. Connected imperviousness levels between 8 and 12% represented a threshold region where minor changes in urbanization could result in major changes in stream condition. In a spatial analysis, connected imperviousness within a 50-m buffer along the stream or within a 1.6-km radius upstream of the sampling site had more influence on stream fish and base flow than did comparable amounts of imperviousness further away. Our results suggest that urban development that minimizes amount of connected impervious surface and establishes undeveloped buffer areas along streams should have less impact than conventional types of development.     

Integrating forage,wildlife, water,and fish projections with timber projections at the regional level: A case study in southern United States

The impact of timber management and land-use change on forage production, turkey and deer abundance, red-cockaded woodpecker colonies, water yield, and trout abundance was projected as part of a policy study focusing on the southern United States. The multiresource modeling framework used in this study linked extant timber management and land-area policy models with newly developed models for forage, wildlife, fish, and water. Resource production was integrated through a commonly defined land base that could be geographically partitioned according to individual resource needs. Resources were responsive to changes in land use, particularly human-related, and timber management, particularly the harvest of older stands, and the conversion to planted pine.     

Ecological principles,biodiversity, and the electric utility industry

The synthetic field of conservation biology uses principles derived from many different disciplines to address biodiversity issues. Many of these principles have come from ecology, and two simple ones that seem to relate to many issues involving the utility industry are: (1) Everything is interconnected (and should usually stay that way), and (2) We can never do merely one thing. The first principle can be applied to both the biotic and physical environments that are impacted by industrial activities. Habitat fragmentation and the loss of physical and biotic connectedness that results are frequently associated with transmission rights-of-way. These problems can be reduced—or even turned into conservation benefits—by careful planning and creative management. The second principle applies to the utility industry's programs to deal with carbon released by burning fossil fuels. Ecological knowledge can allow these programs to contribute to the preservation of biodiversity in addition to addressing a pollution problem. Without careful ecological analyses, industry could easily create new problems while implementing solutions to old ones.     

Past reproductive success affects future habitat selection

Correlational studies have shown that an individual's past reproductive success often increases its breeding site fidelity (i.e., the tendency to return to a previously occupied location), suggesting that individuals use their reproductive experience to assess habitat quality. However, the causality of the relationship between reproductive success and site fidelity is still uncertain. In a field experiment, the effect of mating success on site fidelity was isolated from potential confounding variables in a territorial dragonfly, the eastern amberwing (Perithemis tenera). The experiment controlled for site quality, intrinsic characteristics of males, previous territorial experience at the site, arrival order, and territorial evictions. Males that were prevented from mating were much more likely to change sites the following day than control males that were allowed to mate. This result was not affected by age, the amount of time a male spent on the site, or mortality. These results imply that individuals use their own reproductive success to assess the quality of the habitat. The benefit to an individual of using its reproductive success to determine habitat quality is discussed relative to other sources of information. Received: 31 May 1996 / Accepted: 31 January 1997