Patch Richness Research Articles

Distance makes the difference in thermography for ecological studies

Surface temperature drives many ecological processes and infrared thermography is widely used by ecologists to measure the thermal heterogeneity of different species' habitats. However, the potential bias in temperature readings caused by distance between the surface to be measured and the camera is still poorly acknowledged. We examined the effect of distance from 0.3 to 80m on a variety of thermal metrics (mean temperature, standard deviation, patch richness and aggregation) under various weather conditions and for different structural complexity of the studied surface types (various surfaces with vegetation). We found that distance is a key modifier of the temperature measured by a thermal infrared camera. A non-linear relationship between distance and mean temperature, standard deviation and patch richness led to a rapid under-estimation of the thermal metrics within the first 20m and then only a slight decrease between 20 and 80m from the object. Solar radiation also enhanced the bias with increasing distance. Therefore, surface temperatures were under-estimated as distance increased and thermal mosaics were homogenized at long distances with a much stronger bias in the warmer than the colder parts of the distributions. The under-estimation of thermal metrics due to distance was explained by atmospheric composition and the pixel size effect. The structural complexity of the surface had little effect on the surface temperature bias. Finally, we provide general guidelines for ecologists to minimize inaccuracies caused by distance from the studied surface in thermography.

A toolbox for studying thermal heterogeneity across spatial scales: from unmanned aerial vehicle imagery to landscape metrics

Summary A major barrier for the scientific community of climate change biologists is the spatial mismatch between the size of organisms and the resolution at which global climate data are collected and modelled. Thus, the development of integrative and quantitative tools for the monitoring and spatial characterization of microclimates across spatial scales is a key issue for climate change ecologists. We proposed an integrative toolbox for quantifying the spatial heterogeneity in surface temperatures by bringing together procedures of unmanned aerial vehicles, thermal imagery, orthomosaic, GIS classification and spatial metrics. This toolbox permits to yield high‐resolution visual and infrared orthoimages that are processed into a GIS for selecting surfaces of interest in the landscape (e.g. soil, vegetation). Then, the thermal matrices of selected surfaces (i.e. temperature values of the pixels belonging to the selected surfaces only) are processed within r to generate a variety of thermal landscape metrics (e.g. thermal patch richness and density, thermal aggregation and cohesion index). We applied this toolbox to the thermal characterization of mountainous agricultural landscapes in Ecuador with implications for ectothermic pest dynamics. UAV flights at a height of 60 m above‐ground level allowed us to acquired high‐resolution visual and thermal images (1 and 5 cm/pixel, respectively) for 12 potato fields with a mean surface of 1017 ± 117 m2. Landscape metrics on plant and soil surfaces showed that crop phenology drives the spatial patterns of surface temperatures and strongly modifies the overall thermal ecology of crop fields, with potential implications for ectothermic pest occurrence and dynamics. Overall, our toolbox affords a timely and innovative methodological framework to better assess the thermal heterogeneity of natural landscapes across a wide range of spatial scales. In particular, this toolbox would be of topical interest for ecologists trying to bridge the gap between the resolution of their climatic data and the body size of their study organisms.

Predictors of mammal species richness in KwaZulu-Natal, South Africa

The management of multi-functional landscapes warrants better knowledge of environment-richness associations at varying disturbance levels and habitat gradients. Intensive land-use patterns for agricultural purposes lead to fragmentation of natural habitat resulting in biodiversity loss that can be measured using landscape metrics to assess mammalian richness. Since carnivores and herbivores are likely to show different responses to disturbance, we calculated carnivore, non-carnivore, and total mammal species richness from camera surveys using a first order Jackknife Estimator. Richness was compared along a habitat gradient comprising coastal forest, Acacia thicket, and highland in KwaZulu-Natal, South Africa. We used standardized OLS regression models to identify climatic and disturbance variables, and landscape metrics as predictors of species richness. The estimated total and non-carnivore species richness were highest in coastal forest, while carnivore species richness was highest in highland followed by coastal forest and Acacia thicket. Average monthly maximum temperature was a significant predictor of all richness groups, and precipitation of the wettest month and isothermality determined total and non-carnivore species richness, respectively. These climatic variables possibly limit species distribution because of physiological tolerance of the species. Total mammal richness was determined by mean shape (+) and habitat division (−) while diversity (+) and patch richness (−) explained carnivore species richness. Mean shape index (+) influenced non-carnivore richness. However, habitat division and patch richness negatively influenced total mammal richness. Though habitat patch size and contiguity had a weak positive prediction, these metrics demonstrated the importance of habitat connectivity for maintaining mammal richness. The identification of these climatic and landscape patterns is important to facilitate future landscape management for mammal conservation in forest-mosaics.

Sex-specific indicators of landscape use by servals: Consequences of living in fragmented landscapes

The conversion of wetlands and its associated habitat for farming, residential development and commercial purposes has led to many small disconnected patches of native vegetation surrounded by generally inhospitable human altered land uses. Such human interventions pose a serious threat to the survival of wetland dependent indicator species such as the serval (Leptailurus serval) in the Drakensberg Midlands of KwaZulu-Natal, South Africa. To address the effects of habitat fragmentation on serval space use we used GPS fixes of collared individuals for 100 days between May 2013 and January 2014. We tracked five females and eleven male servals with GPS-UHF collars. Fragmentation indices at the class level (wetland, forest with bushland, grassland and cropland) were measured within the collared serval's minimum convex polygon area (MCP) of home range. Serval use points and fragmentation indices were extracted to each sub-landscape unit of 2km2 falling within the MCP home range. The response of serval population to fragmentation indices was analyzed using generalized linear models at three levels: male, female and the overall population. We found that core area of wetland positively explained landscape use by servals. Effects of forest core area, forest proximity and patch richness were important for landscape use by male servals. Male and female serval use declined with increase in complex shapes of forest and grassland, wetland clumpiness for females and overall, and cropland patches for servals overall. Our results showed that wetland is a key determinant for the survival of male and female servals in fragmented landscapes therefore effective conservation of serval population demands adequate viable native habitat.

A unified modelling approach for producer–scrounger games in complex ecological conditions

Animal decision making in frequency-dependent situations, where the payoff of an action depends on the actions of others, has gained prominence in behavioural ecology and in social foraging in particular. One such situation involves cases where an animal can search for a new resource (produce) or join what others have already found (scrounge). A number of game-theoretic models have been proposed to predict the equilibrium combination of producer and scrounger strategists based on the evolutionarily stable strategy. However, each game model can only handle a few environmental parameters at a time and none address the flexible use of tactics that allows individuals to respond quickly and adaptively to changes in payoffs. In this study we propose an agent-based model using a linear operator learning rule as the decision mechanism. The model provides a unified framework from which to predict the effects on the expected equilibrium of producers and scroungers of group size, metabolic requirement, finder's advantage, food intake rate, cost of searching, cost of joining, patch encounter probability and patch richness. The simulation results replicate almost every producer–scrounger prediction and experimental result published to date such that the simulation provides a more general tool than any single game-theoretic model to predict behaviour under frequency-dependent conditions. The model furthermore allows us to develop a novel prediction about foraging behaviour in a more realistic environment of variable patch richness. By modelling the operation of a plausible decision rule, we can explore the validity of the behavioural gambit, the assumption that the unspecified decision mechanisms of game-theoretic models faithfully reproduce outcomes expected of natural selection operating over generations on fixed alternatives. We suggest that this simulation model can provide a tool for others to explore and predict the effect of more complex and hence realistic foraging conditions on individual levels of producer and scrounger use.

Within-population differences in personality and plasticity in the trade-off between vigilance and foraging in kangaroos

Behavioural traits can vary between individuals from the same population. These differences can involve consistent variation in the level of a particular behaviour (personality) or differences in the way individuals adjust their behaviour to environmental gradients (plasticity). In prey species, feeding rates and vigilance vary with environmental, social and individual factors and the feeding rate/vigilance relationship reflects the trade-off between food acquisition and safety. While feeding rates and vigilance have been shown to vary between individuals in relation to group size and predation risk, how they relate to other factors has not yet been investigated, nor has between-individual variation in this tradeoff. We studied between-individual variation in vigilance, feeding rates and their trade-off in female eastern grey kangaroos, Macropus giganteus, to see whether females showed consistent behavioural differences and different plasticity in relation to ecological (food patch richness), social (group sizes) and physiological (reproductive states) conditions. We addressed two contrasting hypotheses: an ‘ecological’ hypothesis under which individuals facing the same conditions should behave similarly, and a ‘behavioural’ hypothesis under which they should behave differently because of their own personality or plasticity. Female kangaroos tended to adjust their behaviours similarly in relation to ecological and social conditions, supporting the ecological hypothesis. However, they also showed differences in personality and plasticity in relation to their reproductive states that could not be explained by energetic demand alone; this was suggestive of different maternal strategies, thus supporting the behavioural hypothesis. Altogether these results suggest that consistent differences in animals’ personality and behavioural plasticity can be promoted by physiological conditions and are not necessarily repeatable across different ecological contexts.

The Analysis of Landscape Pattern Evolution of Coastal Area in Shanghai Hangzhou Bay North Shore

This paper chooses Shanghai Hangzhou Bay north shore as the study area, to analyze the change of landscape pattern from 1994 to 2007, the data adopts 1994 aerial image and remote sensing image with 5m resolution of 2003 and 2007, land is divided into 11 types: urban land, rural land, factory, farm land, undeveloped land, beach, forest, water, fish ponds, road and railway. FragState3.0 is used to select Class Area (CA), Percentage of Landscape (PLAND), Number of Patches (NP), Patch density (PD), Patch Richness (PR), Shannons Diversity Index (SHDI), Shannons Evenness Index (SHEI) and Dominance (D) to analyze the landscape pattern, the research results reveal that: (1) The law of landscape change in Hangzhou Bay during urbanization process is: water and farmland is converted to undeveloped land at first, thereafter the most part of undeveloped land is converted to factory, the dominant landscape is farmland and its CA change also is the most significant from 44.88% to 34.61% with variation amplitude of 10.27%; (2) From 1994 to 2007, except rural and farmland landscape, the NP of other landscapes increased to varying degrees, fragmentation have increased; (3) Landscape-level indices rise steadily, the SHDI values are relatively high, and all show rising trend; SHEI value is close to 1, indicating the various landscape types is evenly distributed.

Indicators of landscape diversity derived from remote sensing based land cover maps – spatial and thematic aspects

Landscape is heterogeneous part of the Earth surface, forming mosaic of various habitats organized at different scales and levels (Johnson et al. 1992). The landscape pattern has important impact on ecological processes; hence its analysis through quantitative measures is essential for environmental studies. There are many indicators characterizing spatial structure of landscape at different level of detail; they enable analysis of landscape fragmentation at patch level, through studies at habitat level up to complex analyses at landscape level. Seven indicators, which are related to various levels of detail, were selected at the presented work. The following indicators have been studied: Patch Density, Edge Density, Patch Richness, Simpson Diversity Index, Natural Patch Richness, Percentage of Natural Landscape, Mean Natural Patch Area (McGarigal & Marks 1995). First two indicators were used for analysis of landscape fragmentation at patch level, next two at land cover level, while the last three were applied for studies of natural and semi-natural classes at both levels. The studies were performed at six test areas located in different regions of Europe (France, Germany, Poland, Latvia, Spain and Italy), using two different land cover maps. First map was based on Very High Resolution (VHR) Kompsat satellite images (4 m spatial resolution); it included 8 land cover categories with 0.25 ha Minimum Mapping Unit (MMU). CORINE Land Cover (CLC) map 2006 (25 ha MMU) was the second map used for analyses. Number of land cover classes in case of CLC map varied from 9 for Poland till 14 for France. All above mentioned indicators were calculated for grids with 100, 200, 500 and 1000 meter cell size, corresponding to 1, 4, 25 and 100 ha, respectively. The obtained results reveal high usefulness of land cover maps based on VHR satellite images for analysis of landscape fragmentation, even for grids with 100 m cell size. It was found that at patch level these materials are superior to CLC classifications, irrespective of cell area. In case of land cover level VHR data are better while using 100 and 200 m grid cells, whereas for larger cell sizes – 500 and 1000 m – results are not so evident, depending on degree of landscape fragmentation and spatial structure characteristic for individual land cover classes.

三峡库区典型农林流域景观格局对径流和泥沙输出的影响

The Three Gorges Reservoir area is one of China's the most ecologically sensitive areas. Transport and deposition of eroded material as well as substances dissolved in runoff and attached to soil particles lead to declines in water quality, eutrophication and negative impacts to agricultural lands and to waters of the Three Gorges Reservoir. Generally,land use changes,especially the conversion of forests to agriculture in watersheds,are thought to cause these problems. The conversion of cropland to forest as part of an extensive ecological afforestation engineering scheme has played a very important role in reducing runoff and sediment export in this area.Landscape pattern analysis plays an important role in landscape ecology,whose ultimate goal is to link spatial patterns of landscapes with ecological processes and detect status of processes using landscape pattern information. By analyzing the spatial arrangement of relevant factors related to landscapes,landscape pattern analysis can obtain information to predict dynamic patterns of ecological processes. A close relationship exists between land use structure and runoff and sediment export. Landscape patterns have a significant and complex effect on soil erosion and sediment delivery. In this study,a total of 25 typical agroforestry watersheds in Zigui County,Hubei,China,in the Three Gorges Reservoir area were selected to investigate the effects of watershed landscape patterns on runoff and sediment by using RS and GIS techniques. Watershed landscape pattern indices selected were percentage of landscape patch area( PLAND) at the patch-class level,patch richness density,double log fractal dimension( DLFD),Shannon's diversity index( SHDI) and contagion( CONT) at the landscape level. Watershed landscape pattern indices were calculated by FRAGSTATS 4.1. Runoff and sediment exported from 25 watersheds in study area were simulated by the AnnAGNPS( Annualized AGricultural NonPoint Source) model,which is a continuous watershed-scale model that can simulate runoff and sediment in watersheds covering up to 300000 hm2. Correlation between pattern indices and runoff sediment was analyzed using SPSS 19.5 software. The results show a significant positive relationship exists between runoff and CONT and PLANDs of sloping farmlands, terraces,agroforestry terraces and residential land. A significant negative correlation was found between runoff and PLANDs of forestland and shrubland. Soil erosion correlation analysis also showed a significant positive relationship between sediment and DLFD,CONT and PLANDs of sloping farmlands,agroforestry terraces and residential land. A significant negative correlation was found between sediment and SHDI and PLANDs of forestland and shrubland. Multiple correlation coefficients between landscape indices and runoff and sediment were 0.856 and 0.962,respectively,both of which were higher than those of single-factor coefficients. There were linear regression relationships between the landscape indices and runoff and sediment. Landscape pattern significantly influences runoff and sediment delivery in watersheds at the landscape-level. Our results also present empirical evidence for the existence of direct relationship between the landscape patterns in study area and runoff and sediment processes as well as suggest landscape spatial patterns and functional diversity may be linked through feedback mechanisms.

Landscape factors affecting relative abundance of gray foxes Urocyon cinereoargenteus at large scales in Illinois, USA

Evaluation of wildlife‐habitat relationships at the landscape level provides insight into how habitat connectivity, fragmentation and land‐use changes may affect wildlife populations. Although previous studies have demonstrated that habitat composition and configuration at large scales may affect the presence, survival and movement of carnivore species, no such analyses have been conducted for the gray fox Urocyon cinereoargenteus. We used a generalized correlative mapping approach to investigate the relationship of gray fox relative abundance to landscape variables at the county scale in Illinois, USA. Relative abundance of gray foxes was high in 37 of 102 (36%) counties. Four models were competitive based on ΔAICc scores, and these models indicated that standard deviation of the perimeter‐area ratio of agricultural patches, interspersion and juxtaposition index of grassland patches, coefficent of variation of the proximity index of forest patches and relative patch richness of the landscape affected gray fox relative abundance. The variables occurring in our competing models indicate that the relative abundance of the gray fox is higher in counties containing a high level of fragmentation of preferred habitat types (i.e. forests and grasslands) and lower dispersion of less preferred habitat types (i.e. agriculture). Our results reflect gray fox habitat use at smaller scales, and at the landscape scale, gray fox abundance is influenced by how cover‐type patches are configured.

The Effect of Exploration on the Use of Producer-Scrounger Tactics

Individuals foraging in groups can use two different tactics for obtaining food resources. Individuals can either search for food sources themselves (producing) or they can join food discoveries of others (scrounging). In this study we use a genetic algorithm in a spatially explicit producer-scrounger game to explore how individuals compromise between exploration (an important axis of animal personality) and scrounging and how characteristics of the environment affect this compromise. Agents varied in exploration and scrounging and a genetic algorithm searched for the optimal combination of exploration and scrounging. The foraging environments featured different levels of patch richness, predation and patch density. Our simulations show that under conditions of low patch densities slow exploring scroungers were favored whereas high patch density favored fast exploring individuals that either produced (at low patch richness) or scrounged (at high patch richness). In high predation environments fast exploring individuals were selected for but only at low to intermediate patch densities. Predation did not affect scrounging behavior. We did not find a divergence of exploration ‘types’ within a given environment, but there was a general association between exploration and scrounging across different environments: high rates of scrounging were observed over nearly the full spectrum of exploration values, whereas high rates of producing were only observed at high exploration values, suggesting that cases in which slow explorers start producing should be rare. Our results indicate that the spatial arrangement of food resources can affect the optimal social attraction rules between agents, the optimality of foraging tactic and the interaction between both.

Resource dispersion, territory size and group size of black-backed jackals on a desert coast

We studied the relationship between resource—food patch—richness and dispersion on group and territory size of black-backed jackals Canis mesomelas in the Namib Desert. Along beaches where food patches are mostly small, widely separated jackal group sizes are small, and territories are narrow and extremely elongated. Where food patches are rich, fairly clumped and also heterogeneous, group sizes are large and territory sizes small. At a superabundant and highly clumped food source—a large seal rookery—group sizes are large, and territoriality is absent. Although jackals feed at the coast and den nearby, individuals move linearly far inland along well-defined footpaths. The marked climatic gradient from the cold coast inland—a drop in wind speed and rise in effective temperature Te – and use of particular paths by different groups—strongly suggests that these movements are for thermoregulatory reasons only.

Influence of prey dispersion on territory and group size of African lions: a test of the resource dispersion hypothesis

Empirical tests of the resource dispersion hypothesis (RDH), a theory to explain group living based on resource heterogeneity, have been complicated by the fact that resource patch dispersion and richness have proved difficult to define and measure in natural systems. Here, we studied the ecology of African lions Panthera leo in Hwange National Park, Zimbabwe, where waterholes are prey hotspots, and where dispersion of water sources and abundance of prey at these water sources are quantifiable. We combined a 10-year data set from GPS-collared lions for which information of group composition was available concurrently with data for herbivore abundance at waterholes. The distance between two neighboring waterholes was a strong determinant of lion home range size, which provides strong support for the RDH prediction that territory size increases as resource patches are more dispersed in the landscape. The mean number of herbivore herds using a waterhole, a good proxy of patch richness, determined the maximum lion group biomass an area can support. This finding suggests that patch richness sets a maximum ceiling on lion group size. This study demonstrates that landscape ecology is a major driver of ranging behavior and suggests that aspects of resource dispersion limit group sizes.

Effects of landscape structure on butterfly species richness and abundance in agricultural landscapes in eastern Ontario, Canada

The conversion of land from natural areas to agricultural land-use results in changes in landscape pattern, which may affect the presence and distribution of species within these landscapes. Agricultural landscapes with more cover types (higher compositional heterogeneity) should provide more species with the resources necessary to survive. Landscapes with more complex spatial patterns (higher configurational heterogeneity) should allow organisms to obtain resources more efficiently. The objective of this study was to test the predictions that butterfly richness and abundance will be higher in more heterogeneous agricultural landscapes, where heterogeneity was measured by the number of patch types (patch richness) and the number of patches (patch density) in the landscape. Butterflies were sampled at the centers of 40 landscapes in eastern Ontario, Canada. The landscape variables patch density, patch richness and the amount of butterfly habitat were measured for each landscape at multiple spatial scales. Butterfly species richness was higher in landscapes with more butterfly habitat and higher patch density. In contrast, butterfly abundance was higher in landscapes with lower patch richness. Our results suggest that agricultural and environmental policies aimed at maintaining butterfly diversity and abundance should provide incentives for farmers to maintain landscapes with higher configurational heterogeneity and more butterfly habitat.

PREDICTING LANDSCAPE STRUCTURAL METRICS USING ASTER SATELLITE DATA / KRAŠTOVAIZDŽIO STRUKTŪRINIŲ METRIKŲ NUSTATYMAS REMIANTIS ASTER PALYDOVINIAIS DUOMENIMIS

The aim of this study was to predict landscape structural metrics using the features extracted from the ASTER multispectral satellite imagery with 15 m spatial resolution. The landscape structural metrics were calculated on the basis of forest map polygons generated from 1:15000 scaled aerial photos by photo-interpretation technique. The landscape metrics and corresponding image features that are texture parameters and segmentation polygons were determined for four different landscape extents. A stepwise multiple linear regression analysis was carried out to identify the most significant image-derived predictors of landscape metrics for each extent. The regression models established for the landscape metrics including the Number of Patches (NUMP), Edge Density (ED), Shannon's Diversity Index (SDI) and Patch Richness (PR) performed moderately with adjusted R2 values of 0.50 and 0.53 (P<0.01), indicating that 50–53% of the total variation in these landscape metrics can be explained by image-derived features. By contrast, the regression analyses showed that there were weak relationships between the image features and Interspersion Juxtaposition Index (IJI), and Shannon's Evenness Index (SEI) (adj. R2 is varied from 0.12 to 0.30, P<0.01). According to the results of model evaluation, the Entropy measures based on Grey Level Co-occurrence Matrix (GLCM) calculated from the infrared and red bands of ASTER were found as the most correlated parameters with the landscape metrics. Besides, the window size (extent) of 81–144 ha (between 900×900 and 1200×1200 m) might be recommended in estimating the landscape metrics using the ASTER or similar satellite imagery. It can be concluded that the 15 m resolution satellite data used for estimating landscape spatial structure cannot replace aerial photos or very high resolution satellite imagery for local-level inventories. However, it might have potential for predicting landscape heterogeneity for large-scale inventories. Santrauka Tyrimo tikslas buvo prognozuoti kraštovaizdžio struktūrines metrikas, gaunamas iš Aster daugiaspektrių 15 m rezoliucijos palydovinių vaizdų. Atsako kraštovaizdžio struktūrinės metrikos, taikant fotonuotraukų interpretavimo techniką, buvo apskaičiuojamos remiantis miškų žemėlapių, gautų iš 1:15 000 mastelio aerofotonuotraukų, poligonais. Nustatytos keturių skirtingų kraštovaizdžio lygių metrikų ir atitinkamos vaizdų savybės (reljefo parametrai ir poligonų padalijimas). Palaipsnė sudėtinė tiesinė regresinė analizė buvo atliekama identifikuojant reikšmingiausią kiekvieno kraštovaizdžio lygmens atvaizdą. Pagal modelio įvertinimo rezultatus, entropijos matavimo duomenys, pagrįsti Grey lygio tų pačių bendrų įvykių matrica, apskaičiuota remiantis infraraudonųjų spindulių ir ASTER raudonosiomis horizontaliomis juostomis, buvo labiausiai su kraštovaizdžio metrikomis koreliuojantys parametrai. Be to, vertinant kraštovaizdžio metrikas pagal ASTERarpanašius palydovinius duomenis, gali būti rekomenduojama 81–144 ha (tarp 900 ir 900×1200×1200 m) lango dydis (dydis). Galima daryti išvadą, kad 15 m rezoliucijos palydoviniai duomenys, naudojami vertinant kraštovaizdžio erdvinę struktūrą, lokaliajam lygiui inventorizuoti negali pakeisti aerofotonuotraukų ar labai didelės skiriamosios gebos palydovinių vaizdų.

Spatial pattern of landscape changes and consequence changes in species diversity between 1956-1999 of Pinus halepensis Miller plantations in Montes de Malaga State Park (Andalusia, Spain)

Changes in forest diversity and the transforma- tion of coniferous plantations into more natural woodlands are of special interest in the Medi- terranean. The aim of this study was to investi- gate changes in land use patterns and vegeta- tion cover from 1956 to 1999 in Pinus halepensis Miller plantations in Montes de Malaga State Park in southern Spain. At the landscape level, a FRAGSTAT analysis was performed using aerial photographs. At the community level, a total of 47 sample plots were analyzed. Field measure- ments indicated the presence of a total of 70 species in the different vegetation types sam- pled. Shannon-Wiener (H), and Simpson’s (D) diversity indices showed the greatest species richness in Aleppo pine plantations (H = 1.54 ± 0.2; D = 3.88 ± 0.6), while Holm oak stands in the forested areas (H = 1.37 ± 0.1; D = 3.35 ± 0.6) and agricultural land (H = 1.33 ± 0.01; D = 2.80 ± 0.03) had lower values. FRAGSTATS analyses at land- scape and community levels indicated increases in patch richness, patch number, and percent of landscape mainly for pine plantations, Holm oak forests and shrub habitats. Replacement of agri- culture by conifer plantations led to the homo- genization of landscape structure. This change has modified the landscape by facilitating the recovery of indigenous tree species including Holm oak, which will likely lead to the future establishment of native forests in this area. Our findings suggest that pine plantations could fa- vour woody species diversity by increasing abundance and species richness in contrast to the situation in non-forested agricultural land.

Responses of spatial-temporal variation of Karst ecosystem service values to landscape pattern in northwest of Guangxi, China

The responses of spatiotemporal variation of ecosystem service values (ESVs) to landscape pattern from 1985 to 2005 in a typical Karst area of the northwest Guangxi Zhuang Autonomous Region, China, were examined using remote sensing and geographic information system techniques in this paper. The total ecosystem service values declined significantly from 1985 to 1990, and then increased slowly from 1990 to 2005, almost equaled to the 1985 level. The ecosystem service values tended to decline from the west to the east and from mountainous regions to peak-cluster depression areas in 1985, 1990, 2000 and 2005 respectively. During the period from 1985 to 2005, the ecosystem service values have increased in the middle and eastern parts of the study area. Landscape pattern indices, such as total area, largest patch index, contagion, aggregative index, effective mesh and proportion of like adjacencies, are significantly correlated with ecosystem service values. This suggests that ecosystem service values tend to increase with the growth of patch area and patch connectivity. However, there are negative correlations between ecosystem service values and landscape pattern indices, such as division index and patch richness. It indicates that ecosystem service values decrease with patch fragmentation and patch size shrinkage. The ecosystem conditions in the typical Karst area have been improved because of the control measures of rocky desertification. It is important to protect key landscape types, such as woodland, shrub and grassland, and to increase patch size and connectivity to avoid further fragmentation. Furthermore, it is necessary to reduce disturbances to ensure the growth of ecosystem service values and to facilitate the sustainable development in this region.

Spatial patterns of aquatic habitat richness in the Upper Mississippi River floodplain, USA

Interactions among hydrology and geomorphology create shifting mosaics of aquatic habitat patches in large river floodplains (e.g., main and side channels, floodplain lakes, and shallow backwater areas) and the connectivity among these habitat patches underpins high levels of biotic diversity and productivity. However, the diversity and connectivity among the habitats of most floodplain rivers have been negatively impacted by hydrologic and structural modifications that support commercial navigation and control flooding. We therefore tested the hypothesis that the rate of increase in patch richness (# of types) with increasing scale reflects anthropogenic modifications to habitat diversity and connectivity in a large floodplain river, the Upper Mississippi River (UMR). To do this, we calculated the number of aquatic habitat patch types within neighborhoods surrounding each of the ≈19 million 5-m aquatic pixels of the UMR for multiple neighborhood sizes (1–100 ha). For all of the 87 river-reach focal areas we examined, changes in habitat richness ( R) with increasing neighborhood length ( L, # pixels) were characterized by a fractal-like power function R = L z ( R 2 > 0.92 ( P < 0.05)). The scaling exponent ( z) measures the rate of increase in habitat richness with neighborhood size and is related to a fractal dimension. Variation in z reflected fundamental changes to spatial patterns of aquatic habitat richness in this river system. With only a few exceptions, z exceeded the river-wide average of 0.18 in focal areas where side channels, contiguous floodplain lakes, and contiguous shallow-water areas exceeded 5%, 5%, and 10% of the floodplain respectively. In contrast, z was always less than 0.18 for focal areas where impounded water exceeded 40% of floodplain area. Our results suggest that rehabilitation efforts that target areas with <5% of the floodplain in side channels, <5% in floodplain lakes, and/or <10% in shallow-water areas could improve habitat diversity across multiple scales in the UMR.

Improvements in the Finnish Agri-Environment Scheme are Needed in Order to Support Rich Farmland Avifauna

National agri-environment schemes (AESs) aim to promote sustainable farming and protect farmland biodiversity. For efficient maintenance of biodiversity, it is essential to understand the habitat requirements of fauna, and its responses to farming practices. This study examined the importance of different habitat characteristics and habitat heterogeneity for farmland birds in boreal agricultural landscapes, focusing on species in open arable habitats (true field species) and bushy field-edge habitats. Density, species richness, and species composition were studied in a multivariate space, and along environmental gradients. The relevance of the biodiversity-related measures of the Finnish AES regarding the habitat needs of farmland birds was examined. Non-cropped habitat heterogeneity (especially open ditches and habitat patch richness) increased the density and species richness. Crop diversity increased the species richness of true field species. Ordinations revealed a gradient from large open arable to s...

Does landscape composition alter the spatiotemporal distribution of the pine processionary moth in a pine plantation forest?

AbstractLandscape composition and physiognomy affect community structure and species distribution across space and time. The pine processionary moth (PPM) (Thaumetopoea pityocampa Den. &amp; Schiff., Lepidoptera, Notodontidae) is a common pine defoliator throughout southern Europe and Mediterranean countries. We surveyed the spatiotemporal distribution of the PPM in a pine plantation forest in southwestern France and used the density of the winter nests as a proxy for population density. The study spanned 4 years (2005–2008) and showed a high temporal variability in nest density. We found a strong edge effect with nest densities at stand edges more than twice as large as within‐stand densities. At the landscape scale, the spatial distribution of the moth exhibited a significant spatial autocorrelation in 3 out of 4 years of our study. The spatial scales of the autocorrelation ranged from ca. 2 km to more than 22 km. We found a positive correlation between spatial distributions corresponding to certain sampling years, but the relationship was not systematic. Landscape configuration appeared to be an important driver of the PPM spatial pattern. Bivariate Moran's I correlograms showed that patch richness density as well as the percentage of local landscape covered by various land uses were correlated with population density. The study showed that accounting for landscape characteristics may be important in order to understand forest insect pest distribution, even in cases where the host species is abundant and homogeneously distributed throughout the study area, e.g., pure plantation forests.