Spatial and temporal dynamics of habitat availability and stability for a critically endangered arboreal marsupial: implications for conservation planning in a fire-prone landscape

Landscape Ecology - Effective conservation planning for species depends on vegetation models that can capture the dynamics of habitat elements across both spatial and temporal domains....     

Landscape cohesion: an index for the conservation potential of landscapes for biodiversity

In urbanising landscapes, planning for sustainable biodiversity occurs in a context of multifunctional land use. Important conditions for species persistence are habitat quality, the amount and configuration of habitat and the permeability of the landscape matrix. For planning purposes, these determinants should be integrated into simple indicators for spatial conditions of persistence probability. We propose a framework of three related indices. The cohesion index is based on the ecology of metapopulations in a habitat network. We discuss how an indicator for species persistence in such a network could be developed. To translate this network index into an area index, we propose the concept of spatial cohesion. Habitat cohesion and spatial cohesion are defined and measured for single species or, at best, for species profiles. Since species differ in their perception of the same landscape, different species will rate different values of these indices for the same landscape. Because landscapes are rarely planned for single species, we further propose the index of landscape cohesion, which integrates the spatial cohesion indices of different species. Indices based on these concepts can be built into GIS tools for landscape assessment. We illustrate different applications of these indices, and emphasise the distinction between ecological and political decisions in developing and applying such tools. This revised version was published online in August 2006 with corrections to the Cover Date.     

Eighty-year review of the evolution of landscape ecology: from a spatial planning perspective

Landscape Ecology - Sustainable spatial development requires the establishment of a balance between rational land use and the protection of nature, ecosystems and biodiversity on various spatial...     

Small-scale natural landscape features and seabird nesting sites: the importance of geodiversity for conservation

Context

Landscape geodiversity, and in particular small natural features (SNF), are crucial components of habitat suitability for many threatened species. Rocky cliffs at the sea-continent interface present complex small-scale geomorphologies which are exploited by nesting seabirds.

Objectives

Elucidation of the relation between nest-site geomorphology and species preference in cliff-nesting seabirds. Evaluation of the potential of cliff-face SNF as seabird conservation tools.

Methods

Nest site geomorphological characteristics of four Atlantic (Brittany, France) cliff-dwelling seabirds (Razorbill, Guillemot, Fulmar, and Kittiwake) were categorized, and scored for degree of enclosure.

Results

Of the 1048 nest sites examined, the greatest species overlap in location was the mid-region of the cliff face: Fulmar was concentrated in the upper half of the cliff, while Kittiwake showed the most extended vertical distribution. A distinct trend was evident with respect to ceiling presence and size: Razorbill?+?Kittiwake?>?Guillemot?>?Fulmar. Clear trends were also evident in ceiling inclination, ledge size, and side wall presence and inclination. A distinct ‘degree of enclosure’ hierarchy was documented, consolidated with the addition of sympatric species known for their extreme preferences: Atlantic Gannets and Guillemots at the extreme ‘open’ end, and Puffins and Storm Petrels at the extreme ‘closed’ end. Some plasticity in site choice was observed, probably corresponding to sub-optimal default choices.

Conclusions

Despite some plasticity, both vertical level and enclosure characteristics are associated with particular seabird species. Given the importance of nesting sites to seabird reproduction, the identification and conservation of these SNF constitute crucial conservation objectives.

     

Moving beyond landscape resistance: considerations for the future of connectivity modelling and conservation science

Landscape Ecology - Landscape connectivity, the extent to which a landscape facilitates the flow of ecological processes such as organism movement, has emerged as a central focus of landscape...     

From explanation to application: introducing a practice-oriented ecosystem services evaluation (PRESET) model adapted to the context of landscape planning and management

The development and use of the conceptual framework of ecosystem services (ES) has been very successful in supporting the broad diffusion and application of ES within science and policy communities. However, most of the currently proposed interpretations of the framework neither correlate to environmental planning nor to decision-making contexts at the local and regional scale, which is a potential reason for the slow adoption and practice of the ES conceptual framework. This paper proposes a practice-oriented ES evaluation (PRESET) model specifically adapted to the requirements of local and regional planning and decision-making contexts, and discusses its potential benefits and implications for practice. Through the usage of PRESET we suggest making a distinction between ‘offered ES’, ‘utilized ES’, ‘human input’, and ‘ES benefits’ as relevant information for decision-making. Furthermore, we consider it important to link these decision-support categories to different value dimensions relevant in planning and management practice. PRESET provides guidance to inject the ES concept into planning, but needs to be implemented together with concrete assessment methods, indicators and data. The planning strategic benefits of using PRESET include its reference to existing legislative objectives, avoiding the risk that monetized ES values might dominate decision-making, clarification of human contributions, and easier identification of land use conflicts and synergies. Examples are given for offered and utilized ES, as well as for respective evaluation approaches and instruments of implementation.     

Satellite image interpretation (SPOT) for the survey of the ecological infrastructure in a small scaled landscape (Kempenland,Belgium)

This paper deals with the problem of the detectability of the field pattern and the associated linear elements in the Kempenland (Belgium) using SPOT multispectral imagery. The SPOT images are edge-enhanced in order to put the ecological infrastructure in a clearer image display. The detectability is investigated in relation to the size and the shape of the land blocks. The influence on the detectability on SPOT images of the kinds of linear elements, bordering the land blocks, is investigated as well. The use of edge-enhanced SPOT images for (ecological) network analysis (connectivity and circuitry) is also discussed.     

Historic landscape change and habitat loss: the case of black grouse in Lower Saxony,Germany

The declines of many specialist bird species in the agricultural landscapes of Central Europe have resulted in small and isolated populations. In the case of the black grouse, a ground-nesting bird species with large spatial requirements, empiric evidence about underlying landscape changes is scarce. In this study, we examined land cover and land cover changes in a farmland-forest mosaic in eastern Lower Saxony, Germany and how they affect occurrence and persistence of black grouse. Spatial information came from historic topographic maps from 1958 to 1975. The results show profound conversions of habitat to forest and farmland but also an increase in settlement area. Habitat conversions and suburbanization were negative correlates of black grouse persistence. Habitat models from before and after a decline period differed in some of the predictors and suggest black grouse habitat to be more diverse before the land cover changes. Our study confirms that land use factors at a landscape scale extent contribute to explain black grouse occurrence and thus can complement important small scale factors like the quality and size of individual habitat patches. Results also show that landscape factors affect black grouse distribution predominantly from an area much greater than an individual black grouse home range. Our models may be further evaluated on present-day landscapes and might be used to evaluate large-scale habitat availability for black grouse.     

Physical influences of landscape on a large-extent ecological disturbance: the northeastern North American ice storm of 1998

The 1998 ice storm was a large-extent ecological disturbance that severely affected the eastern Adirondack forests of northern New York. Ice damage produced widespread breakage of limbs and trunks in susceptible trees. Although ice storms are common within northeastern North American forests, the magnitude and extent of the 1998 storm far exceeded damage caused by typical ice storms in the recent past. While plot and stand-scale ecological impacts of ice storms have received attention insofar as tree species vulnerability, stand age susceptibility, and microhabitat alterations, larger-extent damage patterns have not been previously evaluated. The normalized difference vegetation index (NDVI) was employed to assess forest vigor and canopy density in atmospherically corrected Landsat Thematic Mapper (TM) satellite imagery of the Adirondacks. Digital change analysis of the baseline forest condition (1990 NDVI data), and the condition encountered in a post-storm image (1998 NDVI data) was conducted. Forest damage was separated from natural variations in canopy reflectance by employing a generalized linear model that incorporated in situ measurements. A robust empirical variogram analysis revealed that locations of tree damage were significantly correlated for distances up to 300 meters. Intensely-damaged forest exhibited greater spatial dependence, but over a smaller distance. Canopy damage was not greater proximate to stream and forest boundaries, and did not follow our hypothesis of decreasing damage with distance from the boundary. Overall, we show that local topography (elevation and aspect), forest composition (deciduous or coniferous), and the meteorological characteristics of the disturbance event acted together to determine the spatial extent of ice storm damage.This revised version was published online in May 2005 with corrections to the Cover Date.     

Impacts of road corridors on urban landscape pattern: a gradient analysis with changing grain size in Shanghai, China

Urbanization is one of the most important driving forces for land use and land cover change. Quantifying urban landscape pattern and its change is fundamental for monitoring and assessing ecological and socioeconomic consequences of urbanization. As the largest city in the country, Shanghai is now the fastest growing city in China. Using land use data set of 2002 and combining gradient analysis with landscape metrics, we analyzed landscape pattern of Shanghai with increasing grain size to study the impacts of road corridors on urban landscape pattern. Landscape metrics were computed along a 51×9 km² transect cutting across Shanghai with a moving window. The results showed that the urban landscape pattern of Shanghai was greatly changed when road corridors were merged with urban patches and the variation of patch density would alter when grain size changed. As a linear land use type, road corridors exhibited a different spatial signature comparing with other land use types and distinctive behavior with increasing grain size. Merging road and urban patches resulted in a sharp reduction in patch density, mainly caused by segmentation of roads corridors. The results suggested that grain size around 7.5 m might be optimal for urban landscape analysis. Landscape patch density is significantly correlated with road percent coverage and the most important effect of road corridors in urban landscape is increased habitat fragmentation.     

Fragmenting fragments: landscape genetics of a subterranean rodent (Mammalia,Ctenomyidae) living in a human-impacted wetland

Landscape Ecology - Anthropogenic activities have detrimental impacts on natural habitats and the species inhabiting them. In particular, habitat fragmentation has a profound effect on the dynamics...     

Some determinants of the spatio-temporal fire cycle in a mediterranean landscape (Corsica,France)

Based on recent needs to accurately understand fire regimes and post-fire vegetation resilience at a supra-level for carbon cycle studies, this article focusses on the coupled history of fire and vegetation pattern for 40 years on a fire-prone area in central Corsica (France). This area has been submitted since the beginning of the 20^th century to land abandonment and the remaining land management has been largely controlled by frequent fires. Our objectives were to rebuild vegetation and fire maps in order to determine the factors which have driven the spatial and temporal distribution of fires on the area, what were the feed backs on the vegetation dynamics, and the long-term consequences of this inter-relationship. The results show a stable but high frequency of small fires, coupled with forest expansion over the study period. The results particularly illustrate the spatial distribution of fires according to topography and vegetation, leading to a strong contrast between areas never burnt and areas which have been burnt up to 7 times. Fires, when occuring, affect on average 9 to 12% of the S, SE and SW facing slopes (compared to only 2 to 5% for the N facing slopes), spread recurrently over ridge tops, affect all the vegetation types but reburn preferentially shrublands and grasslands. As these fire-proning parameters have also been shown to decrease the regeneration capacity of forests, this study highlights the needs in spatial studies (both in terms of fire spread and vegetation dynamic) to accurately apprehend vegetation dynamic and functionning in fire-prone areas.This revised version was published online in May 2005 with corrections to the Cover Date.     

Mapping recreation and aesthetic value of ecosystems in the Bilbao Metropolitan Greenbelt (northern Spain) to support landscape planning

This paper presents a method to quantify cultural ecosystem services (ES) and their spatial distribution in the landscape based on ecological structure and social evaluation approaches. The method aims to provide quantified assessments of ES to support land use planning decisions. A GIS-based approach was used to estimate and map the provision of recreation and aesthetic services supplied by ecosystems in a peri-urban area located in the Basque Country, northern Spain. Data of two different public participation processes (frequency of visits to 25 different sites within the study area and aesthetic value of different landscape units) were used to validate the maps. Three maps were obtained as results: a map showing the provision of recreation services, an aesthetic value map and a map of the correspondences and differences between both services. The data obtained in the participation processes were found useful for the validation of the maps. A weak spatial correlation was found between aesthetic quality and recreation provision services, with an overlap of the highest values for both services only in 7.2 % of the area. A consultation with decision-makers indicated that the results were considered useful to identify areas that can be targeted for improvement of landscape and recreation management.     

Carabids (Coleoptera: Carabidae) in a forest patchwork: a connectivity analysis of the Bereg Plain landscape graph

For many species, one important key to persistence is maintaining connectivity among local populations that allow for dispersal and gene flow. This is probably true for carabid species (Coleoptera:Carabidae) living in the fragmented forests of the Bereg Plain (NE Hungary and W Ukraine). Based on field data, we have drafted a landscape graph of the area representing the habitat network of these species. Graph nodes and links represented two kinds of landscape elements: habitat (forest) patches and corridors, respectively. The quality of habitat patches and corridors were ranked (from low (1) to high (4)), reflecting local population sizes in the case of patches and estimated permeability in the case of corridors. We analysed (1) the positional importance of landscape elements in maintaining the connectivity of the intact network, (2) the effect of inserting hypothetical corridors into the network, (3) the effects of improving the quality of the existing corridors, and (4) how to connect every patch in a cost-effective way. Our results set quantitative priorities for conservation practice by identifying important corridors: what to protect, what to build and what to improve. Several network analytical techniques were used to account for the directed (source-sink) and highly fragmented nature of the landscape graph. We provide conservation priority ranks for the landscape elements and discuss the conditions for the use of particular network indices. Our study could be of extreme relevance, since a new highway is being planned through the area.     

Spatial dynamics of coastal forest bird assemblages: the influence of landscape context,forest type,and structural connectivity

Context

Complex structural connectivity patterns can influence the distribution of animals in coastal landscapes, particularly those with relatively large home ranges, such as birds. To understand the nuanced nature of coastal forest avifauna, where there may be considerable overlap in assemblages of adjacent forest types, the concerted influence of regional landscape context and vegetative structural connectivity at multiple spatial scales warrants investigation.

Objectives

This study determined whether species compositions of coastal forest bird assemblages differ with regional landscape context or with forest type, and if this is influenced by structural connectivity patterns measured at multiple spatial scales.

Methods

Three replicate bird surveys were conducted in four coastal forest types at ten survey locations across two regional landscape contexts in northeast Australia. Structural connectivity patterns of 11 vegetation types were quantified at 3, 6, and 12 km spatial scales surrounding each survey location, and differences in bird species composition were evaluated using multivariate ordination analysis.

Results

Bird assemblages differed between regional landscape contexts and most coastal forest types, although Melaleuca woodland bird assemblages were similar to those of eucalypt woodlands and rainforests. Structural connectivity was primarily correlated with differences in bird species composition between regional landscape contexts, and correlation depended on vegetation type and spatial scale.

Conclusions

Spatial scale, landscape context, and structural connectivity have a combined influence on bird species composition. This suggests that effective management of coastal landscapes requires a holistic strategy that considers the size, shape, and configuration of all vegetative components at multiple spatial scales.

     

Not all forests are alike: the role of commercial forest in the conservation of landscape connectivity for the giant panda

Context

The downlisting of giant panda (Ailuropoda melanoleuca) from Endangered to Vulnerable in IUCN Red List confirms the effectiveness of current conservation practices. However, future survival of giant panda is still in jeopardy due to habitat fragmentation and climate change. Maintaining movement corridors between habitat patches in the newly established Giant Panda National Park (GPNP) is the key for the long-term sustainability of the species.

Objectives

We evaluated the impacts of conversion from natural forest to plantation on giant panda habitat connectivity, which is permitted within collective forests and encouraged by the policies for the economic benefits of local communities. We modeled distribution of giant panda habitat in Minshan Mountains which harbors its largest population, and delineated movement corridors between core habitat patches under management scenarios of different forest conversion proportions.

Methods

We applied an integrated species distribution model based on inhomogeneous Poisson point process to combine presence-only data and site occupancy data, and least-cost models to identify potential movement corridors between core habitat patches.

Results

We found that current distribution of plantation has not damaged connectivity between core habitat patches of giant panda. However, it could be severely degraded if mass conversion occurred. Since the GPNP incorporates all the core habitats identified from our model, controlling natural forest conversion inside GPNP would maintain the movement corridors for giant panda.

Conclusions

We recommend no expansion of plantations inside the GPNP, and improving collective forest management for expansion of ecological forest in adjoining habitat patches.

     

Visual quality: An examination of a South American Mediterranean landscape,Andean foothills east of Santiago (Chile)

This study assessed landscape visual quality in a sector of Andean foothills, east of Santiago, Chile. Sample photographs were taken in four dominant native landscape types that were systematically selected on the basis of four categories of vegetation density. Visitors (n = 180) were randomly sampled from among the residents of Santiago. The results showed that native vegetation has a positive impact on visual quality. Sclerophyllous shrublands and ravines (associated with semi-arid forests) are rated higher than savannahs of “espinales” and shrublands with succulent plants (associated with semi-arid grassland with shrubs). Findings also indicate that landscape scenes with high-vegetation density have a positive effect on visual quality, while those with a low density have a negative one. The key is the amount of visual access, which also increases people's perceptions of safety and orientation. Finally, results showed that information variables are associated with people's visual appreciation. Two preference factors were found to be consistent with the model of spatial information of Kaplan and Kaplan (1989). The implications of the results for the enhancement of public consensus in the planning and management of the Andean foothills, east of Santiago, are also discussed.     

Comparison and development of new graph-based landscape connectivity indices: towards the priorization of habitat patches and corridors for conservation

The loss of connectivity of natural areas is a major threat for wildlife dispersal and survival and for the conservation of biodiversity in general. Thus, there is an increasing interest in considering connectivity in landscape planning and habitat conservation. In this context, graph structures have been shown to be a powerful and effective way of both representing the landscape pattern as a network and performing complex analysis regarding landscape connectivity. Many indices have been used for connectivity analyses so far but comparatively very little efforts have been made to understand their behaviour and sensitivity to spatial changes, which seriously undermines their adequate interpretation and usefulness. We systematically compare a set of ten graph-based connectivity indices, evaluating their reaction to different types of change that can occur in the landscape (habitat patches loss, corridors loss, etc.) and their effectiveness for identifying which landscape elements are more critical for habitat conservation. Many of the available indices were found to present serious limitations that make them inadequate as a basis for conservation planning. We present a new index (IIC) that achieves all the properties of an ideal index according to our analysis. We suggest that the connectivity problem should be considered within the wider concept of habitat availability, which considers a habitat patch itself as a space where connectivity exists, integrating habitat amount and connectivity between habitat patches in a single measure.