共查询到20条相似文献，搜索用时 15 毫秒
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Víctor Arroyo‐Rodríguez Lenore Fahrig Marcelo Tabarelli James I. Watling Lutz Tischendorf Maíra Benchimol Eliana Cazetta Deborah Faria Inara R. Leal Felipe P. L. Melo Jose C. Morante‐Filho Brulio A. Santos Ricard Arasa‐Gisbert Norma Arce‐Pea Martín J. Cervantes‐Lpez Sabine Cudney‐Valenzuela Carmen Galn‐Acedo Miriam San‐Jos Ima C. G. Vieira J.W. Ferry Slik A. Justin Nowakowski Teja Tscharntke 《Ecology letters》2020,23(9):1404-1420
Agriculture and development transform forest ecosystems to human‐modified landscapes. Decades of research in ecology have generated myriad concepts for the appropriate management of these landscapes. Yet, these concepts are often contradictory and apply at different spatial scales, making the design of biodiversity‐friendly landscapes challenging. Here, we combine concepts with empirical support to design optimal landscape scenarios for forest‐dwelling species. The supported concepts indicate that appropriately sized landscapes should contain ≥ 40% forest cover, although higher percentages are likely needed in the tropics. Forest cover should be configured with c. 10% in a very large forest patch, and the remaining 30% in many evenly dispersed smaller patches and semi‐natural treed elements (e.g. vegetation corridors). Importantly, the patches should be embedded in a high‐quality matrix. The proposed landscape scenarios represent an optimal compromise between delivery of goods and services to humans and preserving most forest wildlife, and can therefore guide forest preservation and restoration strategies. 相似文献
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生境破碎是生物多样性下降的主要原因之一。通常以岛屿生物地理学、异质种群生物学和景观生态学的理论来解释不同空间尺度中生境破碎化的生态学效应。生境破碎化引起面积效应、隔离效应和边缘效应。这些效应通过影响动物种群的绝灭阈值、分布和多度、种间关系以及生态系统过程,最终影响动物种群的存活。野外研究表明,破碎化对动物的影响,因物种、生境类型和地理区域不同而有所变化,因此,预测物种在破碎生境中的存活比较困难。研究热点集中于：确定生境面积损失和生境斑块的空间格局对破碎景观中物种绝灭的相对影响,破碎景观中物种的适宜生境比例和绝灭阈值,异质种群动态以及生态系统的生态过程。随着3S技术的发展,生境破碎化模型趋于复杂,而发展有效的模型和验证模型将成为一项富有挑战性的任务。 相似文献
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Ilkka Hanski 《Journal of Biogeography》2015,42(5):989-993
In a recent article in this journal, Fahrig (2013, Journal of Biogeography, 40 , 1649–1663) concludes that variation in species richness among sampling sites can be explained by the amount of habitat in the ‘local landscape’ around the sites, while the spatial configuration of habitat within the landscape makes little difference. This conclusion may be valid for small spatial scales and when the total amount of habitat is large, but modelling and empirical studies demonstrate adverse demographic consequences of fragmentation when there is little habitat across large areas. Fragmentation effects are best tested with studies on individual species rather than on communities, as the latter typically consist of species with dissimilar habitat requirements. The total amount of habitat and the degree of fragmentation tend to be correlated, which poses another challenge for empirical studies. I conclude that fragmentation poses an extra threat to biodiversity, in addition to the threat posed by loss of habitat area. 相似文献
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Cristian Echeverría Adrian C. Newton Antonio Lara José María Rey Benayas David A. Coomes 《Global Ecology and Biogeography》2007,16(4):426-439
Aim Few studies have explicitly examined the influence of spatial attributes of forest fragments when examining the impacts of fragmentation on woody species. The aim of this study was to assess the diverse impacts of fragmentation on forest habitats by integrating landscape‐level and species‐level approaches. Location The investigation was undertaken in temperate rain forests located in southern Chile. This ecosystem is characterized by high endemism and by intensive recent changes in land use. Method Measures of diversity, richness, species composition, forest structure and anthropogenic disturbances were related to spatial attributes of the landscape (size, shape, connectivity, isolation and interior forest area) of forest fragments using generalized linear models. A total of 63 sampling plots distributed in 51 forest fragments with different spatial attributes were sampled. Results Patch size was the most important attribute influencing different measures of species composition, stand structure and anthropogenic disturbances. The abundance of tree and shrub species associated with interior and edge habitats was significantly related to variation in patch size. Basal area, a measure of forest structure, significantly declined with decreasing patch size, suggesting that fragmentation is affecting successional processes in the remaining forests. Small patches also displayed a greater number of stumps, animal trails and cow pats, and lower values of canopy cover as a result of selective logging and livestock grazing in relatively accessible fragments. However, tree richness and β‐diversity of tree species were not significantly related to fragmentation. Main conclusions This study demonstrates that progressive fragmentation by logging and clearance is associated with dramatic changes in the structure and composition of the temperate forests in southern Chile. If this fragmentation process continues, the ability of the remnant forests to maintain their original biodiversity and ecological processes will be significantly reduced. 相似文献
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Santiago Saura 《Journal of Biogeography》2021,48(1):11-22
The habitat amount hypothesis (HAH) predicts that species richness in a habitat site increases with the amount of habitat in the ‘local landscape’ defined by an appropriate distance around the site, with no distinct effects of the size of the habitat patch in which the site is located. It has been stated that a consequence of the HAH, if supported, would be that it is unnecessary to consider habitat configuration to predict or manage biodiversity patterns, and that conservation strategies should focus on habitat amount regardless of fragmentation. Here, I assume that the HAH holds and apply the HAH predictions to all habitat sites over entire landscapes that have the same amount of habitat but differ in habitat configuration. By doing so, I show that the HAH actually implies clearly negative effects of habitat fragmentation, and of other spatial configuration changes, on species richness in all or many of the habitat sites in the landscape, and that these habitat configuration effects are distinct from those of habitat amount in the landscape. I further show that, contrary to current interpretations, the HAH is compatible with a steeper slope of the species–area relationship for fragmented than for continuous habitat, and with higher species richness for a single large patch than for several small patches with the same total area (SLOSS). This suggests the need to revise the ways in which the HAH has been interpreted and can be actually tested. The misinterpretation of the HAH has arisen from confounding and overlooking the differences in the spatial scales involved: the individual habitat site at which the HAH gives predictions, the local landscape around an individual site and the landscapes or regions (with multiple habitat sites and different local landscapes) that need to be analysed and managed. The HAH has been erroneously viewed as negating or diminishing the relevance of fragmentation effects, while it actually supports the importance of habitat configuration for biodiversity. I conclude that, even in the cases where the HAH holds, habitat fragmentation and configuration are important for understanding and managing species distributions in the landscape. 相似文献
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Habitat fragmentation is a potentially critical factor in determining population persistence. In this paper, we explore the effect of fragmentation when the fragmentation follows a fractal pattern. The habitat is divided into patches, each of which is suitable or unsuitable. Suitable patches are either occupied or unoccupied, and change state depending on rates of colonization and local extinction. We compare the behaviour of two models: a spatially implicit patch-occupancy (PO) model and a spatially explicit cellular automaton (CA) model. The PO model has two fixed points: extinction, and a stable equilibrium with a fixed proportion of occupied patches. Global extinction results when habitat destruction reduces the proportion of suitable patches below a critical threshold. The PO model successfully recreates the extinction patterns found in other models. We translated the PO model into a stochastic cellular automaton. Fractal arrangements of suitable and unsuitable patches were used to simulate habitat fragmentation. We found that: (i) a population on a fractal landscape can tolerate more habitat destruction than predicted by the patch-occupancy model, and (ii) the extinction threshold decreases as the fractal dimension of the landscape decreases. These effects cannot be seen in spatially implicit models. Landscape struc-ture plays a vital role in mediating the effects of habitat fragmentation on persistence. 相似文献
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Abstract. 1. Habitat requirements and occurrence patterns of three species of burnet moths (Zygaena filipendulae, Zygaena lonicerae and Zygaena viciae) were studied at different life stages and different scales on the Baltic island of Öland, Sweden. 2. Larvae of all three species were more likely to occur in small‐scale patches (i.e. 1 m2) with a greater cover of their most important host plants, Lotus corniculatus, Trifolium medium/pratense, or Vicia spp., than were pupae or adults, and were also observed on significantly larger than random plants. Pupation of Z. filipendulae took place in taller vegetation than preferred by feeding larvae and adults. 3. Adults of all species preferred different nectar plants of Asteraceae and Dipsacaceae, growing in sunny conditions. 4. A large‐scale analysis of occupancy patterns was made, evaluating the relationship between burnet occurrence and the area of meadows and pastures within 10 × 10 km grid cells in Sweden. All three species showed a significant positive relationship with the area of semi‐natural grassland. The area required for a 50% probability of burnet occurrence was 454 ha for Z. filipendulae, 925 ha for Z. lonicerae and 2055 ha for Z. viciae. 5. Conservation work should aim at preserving and restoring open areas rich in the respective host plants and nectar sources, with light grazing or mowing late in the season. At the landscape scale, burnet moths were favoured by a high density of semi‐natural grassland and management priorities should be directed to these regions. 相似文献
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Rachel Chocron Curtis H. Flather Ronen Kadmon 《Global Ecology and Biogeography》2015,24(11):1225-1235
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Abstract. In southwestern Ontario amphibian species richness (α-diversity) was investigated at 180 ponds from 1992 to 1994. Patterns of species richness were compared among regions and the relationship between species richness and local habitat and regional landscape variables was investigated. Patterns of incidence differed among regions, with species that use woodlands being rare in one of the regions. Repeated measures analysis of variance indicated that species richness differed significantly among regions but not among sub-regions nested within regions. Species richness did not change significantly over time and there was no region by year effect. Species richness was highly correlated with local variables related to fish predation and to regional variables related to forest cover. Multiple regression indicated that a combination of local and regional variables best accounted for the variance in species richness, but the amount of regional woodlands was the single most important variable. The pattern of species richness can be explained by historical deforestation as the primary process. 相似文献
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Marília Bruzzi Lion Adrian Antonio Garda Carlos Roberto Fonseca 《Diversity & distributions》2014,20(11):1245-1257
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Alessio Mortelliti Stefano Fagiani Corrado Battisti Dario Capizzi Luigi Boitani 《Diversity & distributions》2010,16(6):941-951
Aim Habitat loss and fragmentation are amongst the greatest threats to biodiversity world‐wide. However, there is still little evidence on the relative influence of these two distinct processes on biodiversity, and no study, to date, has investigated the independent contribution of structural connectivity in addition to habitat loss and fragmentation. The aim of this study is to evaluate the independent effects of habitat loss (the decrease in total amount of habitat), habitat fragmentation per se (habitat subdivision) and structural connectivity (in the form of hedgerow networks) on the distribution of seven resident forest‐dependent birds in central Italy. Location Central Italy. Methods We strategically selected 30 landscapes (each of 16 km2 in size) with decreasing total amount of forest cover and with contrasting configuration of patches and contrasting lengths of hedgerow networks. Presence/absence of birds in each landscape unit was studied through point counts. Results The amount of forest cover in the landscape had the strongest relative influence on birds’ occupancy, whilst habitat subdivision played a negligible role. Structural connectivity and the geographic position of the landscape unit played a relatively important role for four species. Main conclusions Our study shows the importance of disentangling the contribution of different landscape properties in determining distribution patterns. Our results are consistent with the fact that halting habitat loss and carrying out habitat restoration should be conservation priorities, since habitat loss is the main factor affecting the distribution of the target species; implementation of structural connectivity through hedgerows, instead, should be evaluated with caution since its contribution is secondary to the predominant role of habitat loss. 相似文献
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Thomas Merckx Murilo Dantas de Miranda Henrique M. Pereira 《Journal of Biogeography》2019,46(5):956-967
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Marília B. Lion Adrian A. Garda Diego J. Santana Carlos Roberto Fonseca 《Biotropica》2016,48(2):265-275
Loss and fragmentation of natural habitats are key contributors to the decline of populations and impoverishment of biological communities. The response to these disturbances can vary substantially among taxa and depends on spatial metrics of habitat fragments and the surrounding landscape. Herein we test how fragment area, shape, isolation, and matrix quality affect reptile richness, abundance, and occurrence in Brazilian Atlantic Forest fragments, a biodiversity hotspot with a poorly studied reptile fauna. We used 23 forest fragments, ranging from 2 to 30 hectares, surrounded by different matrix types, including sugarcane crop fields, cattle ranching, subsistence farmlands and rural communities. Species richness, total reptile abundance, population abundance, and occurrence probability of many species decreased with fragment area. Model selection suggested that fragment area is the main predictor of both richness and abundance, but matrix quality as well as fragment shape are also important predictors. For population abundance and occurrence probability, fragment area and proximity were the most important predictors followed by fragment shape and matrix quality, but the strength and even the sign of predictors varied substantially among species. We highlight that the value of small fragments should not be neglected for the conservation of Atlantic Forest reptiles. 相似文献
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Stephanie A. Pulsford David B. Lindenmayer Don A. Driscoll 《Diversity & distributions》2017,23(12):1408-1422