A Multispecies Framework for Landscape Conservation Planning

Abstract: Rapidly changing landscapes have spurred the need for quantitative methods for conservation assessment and planning that encompass large spatial extents. We devised and tested a multispecies framework for conservation planning to complement single‐species assessments and ecosystem‐level approaches. Our framework consisted of 4 elements: sampling to effectively estimate population parameters, measuring how human activity affects landscapes at multiple scales, analyzing the relation between landscape characteristics and individual species occurrences, and evaluating and comparing the responses of multiple species to landscape modification. We applied the approach to a community of terrestrial birds across 25,000 km² with a range of intensities of human development. Human modification of land cover, road density, and other elements of the landscape, measured at multiple spatial extents, had large effects on occupancy of the 67 species studied. Forest composition within 1 km of points had a strong effect on occupancy of many species and a range of negative, intermediate, and positive associations. Road density within 1 km of points, percent evergreen forest within 300 m, and distance from patch edge were also strongly associated with occupancy for many species. We used the occupancy results to group species into 11 guilds that shared patterns of association with landscape characteristics. Our multispecies approach to conservation planning allowed us to quantify the trade‐offs of different scenarios of land‐cover change in terms of species occupancy.     

Mapping Human and Social Dimensions of Conservation Opportunity for the Scheduling of Conservation Action on Private Land

Abstract Spatial prioritization techniques are applied in conservation‐planning initiatives to allocate conservation resources. Although typically they are based on ecological data (e.g., species, habitats, ecological processes), increasingly they also include nonecological data, mostly on the vulnerability of valued features and economic costs of implementation. Nevertheless, the effectiveness of conservation actions implemented through conservation‐planning initiatives is a function of the human and social dimensions of social‐ecological systems, such as stakeholders’ willingness and capacity to participate. We assessed human and social factors hypothesized to define opportunities for implementing effective conservation action by individual land managers (those responsible for making day‐to‐day decisions on land use) and mapped these to schedule implementation of a private land conservation program. We surveyed 48 land managers who owned 301 land parcels in the Makana Municipality of the Eastern Cape province in South Africa. Psychometric statistical and cluster analyses were applied to the interview data so as to map human and social factors of conservation opportunity across a landscape of regional conservation importance. Four groups of landowners were identified, in rank order, for a phased implementation process. Furthermore, using psychometric statistical techniques, we reduced the number of interview questions from 165 to 45, which is a preliminary step toward developing surrogates for human and social factors that can be developed rapidly and complemented with measures of conservation value, vulnerability, and economic cost to more‐effectively schedule conservation actions. This work provides conservation and land management professionals direction on where and how implementation of local‐scale conservation should be undertaken to ensure it is feasible.     

Designing a Conservation Landscape for Tigers in Human-Dominated Environments

Abstract:  Wildlife populations in small, isolated reserves face genetic and demographic threats to their survival. To increase the probability of long-term persistence, biologists promote metapopulation management, in which breeding subpopulations are protected as source pools. Animals that disperse from the source pools increase the probability of persistence of the metapopulation across the greater landscape. We used a geographic information system (GIS)–based, cost-distance model to design a conservation landscape along the Himalayan foothills for managing a metapopulation of Asia's largest predator, the tiger ( Panthera tigris ). The model is based on data from 30 years of field research on tigers, recent satellite imagery, and a decade of buffer-zone restoration in this region. We used the model to (1) identify potential dispersal corridors for tigers; (2) identify strategic transit refuges; and (3) make recommendations for off-reserve land management and restoration to enhance the potential of corridors for tigers. This tool can aid the design of conservation landscapes for other endangered, wide-ranging species in human-dominated environments.     

The Application of Neutral Landscape Models in Conservation Biology

Neutral landscape models, derived from percolation theory in the field of landscape ecology, are grid-based maps in which complex habitat distributions are generated by random or fractal algorithms. This grid-based representation of landscape structure is compatible with the raster-based format of geographical information systems (GIS), which facilitates comparisons between theoretical and real landscapes. Neutral landscape models permit the identification of critical thresholds in connectivity, which can be used to predict when landscapes will become fragmented. The coupling of neutral landscape models with generalized population models, such as metapopulation theory, provides a null model for generating predictions about population dynamics in fragmented landscapes. Neutral landscape models can contribute to the following applications in conservation: (1) incorporation of complex spatial patterns in (meta)population models; (2) identification of species' perceptions of landscape structure; (3) determination of landscape connectivity; (4) evaluation of the consequences of habitat fragmentation for population subdivision; (5) identification of the domain of metapopulation dynamics; (6) prediction of the occurrence of extinction thresholds; ( 7) determination of the genetic consequences of habitat fragmentation; and (8) reserve design and ecosystem management. This generalized, spatially explicit framework bridges the gap between spatially implicit, patch-based models and spatially realistic GIS applications which are usually parameterized for a single species in a specific landscape. Development of a generalized, spatially explicit framework is essential in conservation biology because we will not be able to develop individual models for every species of management concern.     

Proposed Conservation Landscape for Giant Pandas in the Minshan Mountains,China

Abstract: The giant panda (Ailuropoda melanoleuca), is one of the world's most endangered species. Habitat loss and fragmentation have reduced its numbers, shrunk its distribution, and separated the population into isolated subpopulations. Such isolated, small populations are in danger of extinction due to random demographic factors and inbreeding. We used least‐cost modeling as a systematic approach to incorporate satellite imagery and data on ecological and behavioral parameters of the giant panda collected during more than 10 years of field research to design a conservation landscape for giant pandas in the Minshan Mountains. We identified 8 core habitats and 4 potential linkages that would link core habitats CH3, CH4, and CH5 with core habitats CH6, CH7, and CH8. Establishing and integrating the identified habitats with existing reserves would create an efficient reserve network for giant panda conservation. The core habitats had an average density of 4.9 pandas/100 km² and contained approximately 76.6% of the giant panda population. About 45% of the core habitat (3245.4 km²) existed outside the current nature reserves network. Total estimated core habitat decreased between 30.4 and 44.5% with the addition of residential areas and road networks factored into the model. A conservation area for giant panda in the Minshan Mountains should aim to ensure habitat retention and connectivity, improve dispersal potential of corridors, and maintain the evolutionary potential of giant pandas in the face of future environmental changes.     

A Graph-Theory Framework for Evaluating Landscape Connectivity and Conservation Planning

Abstract:  Connectivity of habitat patches is thought to be important for movement of genes, individuals, populations, and species over multiple temporal and spatial scales. We used graph theory to characterize multiple aspects of landscape connectivity in a habitat network in the North Carolina Piedmont (U.S.A).^. We compared this landscape with simulated networks with known topology, resistance to disturbance, and rate of movement. We introduced graph measures such as compartmentalization and clustering, which can be used to identify locations on the landscape that may be especially resilient to human development or areas that may be most suitable for conservation. Our analyses indicated that for songbirds the Piedmont habitat network was well connected. Furthermore, the habitat network had commonalities with planar networks, which exhibit slow movement, and scale-free networks, which are resistant to random disturbances. These results suggest that connectivity in the habitat network was high enough to prevent the negative consequences of isolation but not so high as to allow rapid spread of disease. Our graph-theory framework provided insight into regional and emergent global network properties in an intuitive and visual way and allowed us to make inferences about rates and paths of species movements and vulnerability to disturbance. This approach can be applied easily to assessing habitat connectivity in any fragmented or patchy landscape.     

Incorporating Habitat Mapping into Practical Koala Conservation on Private Lands

Abstract: Identifying and conserving faunal habitat on private lands has been conducted largely on a site-by-site basis as development proposals arise. We sought to map koala habitat at a scale suitable for use by a local planning authority so that habitat remnants could be protected and managed while remaining in private ownership. At this scale, the level of detail and accuracy needed by local planners required a new approach to mapping koala habitat. Two independent techniques, community and field surveys, were employed. We mailed a survey to every household in Coffs Harbour shire. Respondents told of 3309 koala sightings. We conducted a field survey, a plot-based scat (  fecal pellet) search, to determine which vegetation types and tree species were preferred by koalas. We surveyed 119 sites, which contained 42 different vegetation types. Of these, 37 (31%) had been used by koalas. The outcomes of the community and field surveys were combined to produce a distribution map of koala habitat. The most striking outcome has been the use of our results by the local government authority, Coffs Harbour City Council: planners have incorporated the koala habitat map into their local environmental plan. Our procedure offers a rigorous, repeatable, and publicly accessible method for identifying and mapping important habitat for the purposes of land-use planning, an essential procedure for conserving habitat outside the reserve system.     

Influence of Landscape Elements in Riparian Buffers on the Conservation of Semiaquatic Amphibians

Abstract:  Studies on riparian buffers have usually focused on the amount of land needed as habitat for the terrestrial life stages of semiaquatic species. Nevertheless, the landscape surrounding wetlands is also important for other key processes, such as dispersal and the dynamics of metapopulations. Multiple elements that influence these processes should therefore be considered in the delineation of buffers. We analyzed landscape elements (forest cover, density of roads, and hydrographic network) in concentric buffers to evaluate the scale at which they influence stream amphibians in 77 distinct landscapes. To evaluate whether our results could be generalized to other contexts, we determined whether they were consistent across the study areas. Amphibians required buffers of 100–400 m of suitable terrestrial habitat, but interspecific differences in the amount of habitat were large. The presence of amphibians was related to roads and the hydrographic network at larger spatial scales (300–1500 m), which suggests that wider buffers are needed with these elements. This pattern probably arose because these elements influence dispersal and metapopulation persistence, processes that occur at large spatial scales. Furthermore, in some cases, analyses performed on different sets of landscapes provided different results, which suggests caution should be used when conservation recommendations are applied to disparate areas. Establishment of riparian buffers should not be focused only on riparian habitat, but should take a landscape perspective because semiaquatic species use multiple elements for different functions. This approach can be complex because different landscape elements require different spatial extents. Nevertheless, a shift of attention toward the management of different elements at multiple spatial scales is necessary for the long-term persistence of populations.     

Importance of Reserve Size and Landscape Context to Urban Bird Conservation

Abstract:  We tested whether reserve size, landscape surrounding the reserve, and their interaction affect forest songbirds in the metropolitan area of Seattle, Washington (U.S.A.), by studying 29 reserves of varying size (small, medium, large) and surrounding urbanization intensity (urban, suburban, exurban). Larger reserves contained richer and less even bird communities than smaller reserves. These size effects disappeared when we removed the positive correlation of shrub diversity with reserve size, suggesting that greater habitat diversity in large reserves supported additional species, some of which were rare. Standardizing the number of individuals detected among all reserve size classes reversed the effect of size on richness in exurban landscapes and reduced the magnitude of the effect in suburban or urban landscapes. The latter change suggested that richness increased with reserve size in most landscapes because larger areas also supported larger samples from the regional bird species pool. Most bird species associated with native forest habitat (native forest species) and with human activity (synanthropic species) were present in reserves larger than 42 ha and surrounded by >40% urban land cover, respectively. Thus, we recommend these thresholds as means for conserving the composition of native bird communities in this mostly forested region. Native forest species were least abundant and synanthropic species most abundant in urban landscapes, where exotic ground and shrub vegetation was most common. Therefore, control of exotic vegetation may benefit native songbird populations. Bird nests in shrubs were most dense in medium (suburban) and large reserves (urban) and tended to be most successful in medium (suburban) and large reserves (exurban), potentially supplying another mechanism by which reserve size increased retention of native forest species.     

A Landscape Approach to Biodiversity Conservation of Sacred Groves in the Western Ghats of India

Abstract:  Although sacred groves are important for conservation in India, the landscape that surrounds them has a vital influence on biodiversity within them. Research has focused on tree diversity inside these forest patches. In a coffee-growing region of the Western Ghats, however, landscape outside sacred groves is also tree covered because planters have retained native trees to provide shade for coffee plants. We examined the diversity of trees, birds, and macrofungi at 58 sites—10 forest-reserve sites, 25 sacred groves, and 23 coffee plantations— in Kodagu district. We measured landscape composition and configuration around each site with a geographic information system. To identify factors associated with diversity we constructed multivariate models by using a decision-tree technique. The conventional measures of landscape fragmentation such as patch size did not influence species richness. Distance of sacred groves from the forest reserve had a weak influence. The measures of landscape structure (e.g., tree cover in the surroundings) and stand structure (e.g., variability in canopy height) contributed to the variation in species richness explained by multivariate models. We suggest that biodiversity present within sacred groves has been influenced by native tree cover in the surrounding landscape. To conserve this biodiversity the integrity of the tree-covered landscape matrix will need to be conserved.     

Conservation of Epiphyte Diversity in an Andean Landscape Transformed by Human Land Use

Abstract: Epiphytes are diverse and important elements of tropical forests, but as canopy‐dwelling organisms, they are highly vulnerable to deforestation. To assess the effect of deforestation on epiphyte diversity and the potential for epiphyte conservation in anthropogenically transformed habitats, we surveyed the epiphytic vegetation of an Ecuadorian cloud forest reserve and its surroundings. Our study was located on the western slopes of the Andes, a global center of biodiversity. We sampled vascular epiphytes of 110 study plots in a continuous primary forest; 14 primary forest fragments; isolated remnant trees in young, middle‐aged, and old pastures; and young and old secondary forests. It is the first study to include all relevant types of habitat transformation at a single study site and to compare epiphyte diversity at different temporal stages of fragmentation. Epiphyte diversity was highest in continuous primary forest, followed by forest fragments and isolated remnant trees, and lowest in young secondary forests. Spatial parameters of habitat transformation, such as fragment area, distance to the continuous primary forest, or distance to the forest edge from inside the forest, had no significant effect on epiphyte diversity. Hence, the influence of dispersal limitations appeared to be negligible or appeared to operate only over very short distances, whereas microclimatic edge effects acted only in the case of completely isolated trees, but not in larger forest fragments. Epiphyte diversity increased considerably with age of secondary forests, but species assemblages on isolated remnant trees were impoverished distinctly with time since isolation. Thus, isolated trees may serve for recolonization of secondary forests, but only for a relatively short time. We therefore suggest that the conservation of even small patches of primary forest within agricultural landscape matrices is essential for the long‐term maintenance of the high epiphyte diversity in tropical cloud forests.     

The Potential for Conservation of Polynesian Birds through Habitat Mapping and Species Translocation

Abstract: The dependency of highly endemic island floras on few potential pollinators in depauperate island faunas suggests that pollinators and seed dispersers may be crucial in the preservation of biodiversity in isolated oceanic islands. We discuss the hypothesis that flying foxes are "strong interactors" in South Pacific islands where they setwe as the principal pollinators and seed dispersers, This suggests that the ongoing decline and ultimate extinction of flying fox species on Pacific islands may lead to a cascade of linked plant extinctions. We propose an empirical test of this hypothesis: comparisons of plant reproductive success in Guam, which has virtually lost its flying fox populations, and Samoa, where signifcant populations remain.     

黄山风景区第四纪冰川遗迹的景观特征与保护措施

黄山是我国著名的风景名胜区及世界重要的人类自然和文化遗产,具有观赏游览、科学研究及文化艺术活动等功能。为了实现旅游经济与生态环境的协调和可持续发展,提出了在黄山风景区内划分特殊自然及人文景观保护小区的观点,并划出第四纪冰川遗迹、花岗岩石林地貌、泥炭藓沼泽、松林及温泉等景观生态保护小区。主要探讨黄山风景区第四纪冰川遗迹景观生态保护小区的分布、特征及保护措施。