Habitat Fragmentation Research Articles

Reptiles and amphibians from the fragments of seasonal Atlantic Forest in northern Paraná, Brazil

Reptiles and amphibians from the fragments of seasonal Atlantic Forest in northern Paraná, Brazil

Characterization of land use, from a social, economic and environmental dynamics

Characterization of land use, from a social, economic and environmental dynamics

Comparing landscape characteristics to understand Malayan tapir (Tapirus indicus) conflicts: A case study in Negeri Sembilan

The IUCN Red List has listed the Malayan tapir (Tapirus indicus) as an endangered species in 2016, owing to its declining population trend. Human-caused forest degradation and encroachment on wildlife habitats drive this species to roam out of its natural range, resulting in human-tapir conflict (HTC). This study executes kernel density analysis on 78 HTC points recorded in Negeri Sembilan from 2013 to 2018 to determine the high and low HTC zones, and investigates the influence of five landscape variables on the occurrence of HTC. Values of five landscape variables in high and low HTC zones were extracted, and the significance of occurrence between these two zones was tested using an independent sample t-test. In terms of spatial distribution, Kuala Pilah and Jelebu covered high-conflict zones, while the lowest conflict zone was in Rembau. The t-test indicated that elevation (t = –3.551, p < 0.05) and slope (t = –2.012, p < 0.05) were significant between high and low conflict zones. Distance to the forest (t = 1.424, p > 0.05), distance to water (t = –0.106, p > 0.05), and distance to urban areas (t = –1.536, p > 0.05) were not significant for HTC. HTC tends to occur in low topographic areas, while tapirs outside of their natural habitat forage in close proximity to the forest and water bodies, but restrict their movement near human settlements. Hot Spot Analysis (Getis-Ord Gi*) on forest patches revealed an overlaping region between high HTC zones and low forest-patch contiguity, indicating that forest fragmentation may promote tapir conflicts. Hence, by systematically recording the conflict distribution in Negeri Sembilan, many actions could be taken into consideration to mitigate HTC in this state.

Loquat (Eriobotrya japonica) fruit consumption and preference by cloud forest birds: Implications for woody native species regeneration

Secondary forests from abandoned shade coffee plantations are commonly found close to Neotropical cities. These peri-urban forests provide important environmental services; however, their abandonment and proximity to the city can promote an increase of exotic species that could potentially change the structure and function of the system by creating novel ecosystems. The loquat (Eriobotrya japonica) is a tree native to Asia and is recognized as a potentially invasive species in the tropical montane cloud forest region of Central Veracruz, Mexico. We analyzed the consumption of and preference for loquat fruits in cloud forest frugivorous birds. In November 2020, we established six feeding stations with camera traps in a peri-urban cloud forest fragment in Xalapa, Mexico. To determine which bird species could consume and disperse E. japonica, fruits of this and another four native species (Psychotria nervosa, Hoffmannia excelsa, Picramnia antidesma, and Xylosma flexuosa) were exposed separately. After 444 camera-days, we recorded eight frugivorous bird species, seven of which consumed E. japonica fruits. Chlorospingus flavopectus was the only species to present a level of loquat fruit consumption greater than that expected by chance. We conducted experiments to assess whether the birds preferred to consume E. japonica fruits compared to those from three native species (Cestrum miradorense, P. nervosa, and X. flexuosa) that were offered simultaneously. All bird species exclusively consumed E. japonica fruits when contrasted against P. nervosa or X. flexuosa. The only native species fruits that were consumed were those of C. miradorense, although the birds also preferred to consume loquat fruits rather than this native species. The loquat therefore represents an important food resource and could act to influence the consumption and dispersal of native cloud forest plant species. The implications for cloud forest management are discussed.

The effects of recreational footpaths on terrestrial invertebrate communities in a UK ancient woodland: a case study from Blean Woods, Kent, UK

ABSTRACT Globally, terrestrial invertebrates are in decline, in part due to habitat fragmentation. Footpaths provide nature-based recreation to the public but can present small-scale spatially continuous changes in forest dynamics. However, their effects on terrestrial invertebrate communities are unknown. Pitfall trapping was undertaken to identify whether terrestrial invertebrate communities were disrupted by a popular recreational footpath in Blean Woods, an ancient UK woodland. The study identified 720 invertebrates across 36 taxa from 20 footpath edge and forest interior traps. It was found that footpaths did not significantly affect terrestrial invertebrate communities. There was no difference in the taxonomic abundance, richness, and diversity; invertebrate trait abundance and richness; or invertebrate community composition between the footpath edge and woodland interior traps. Thus, footpaths in Blean Woods do not disturb the terrestrial invertebrate community, and therefore present a sustainable mechanism for facilitating public engagement with conservation in a nationally important protected ancient woodland.

Downstream passage performance of silver eel at an angled rack: effects of behavior and morphology

The European eel is critically endangered due to heavy impact of anthropogenic factors, such as habitat fragmentation, overexploitation and climate change. During downstream migration, silver eels may encounter hydropower plants, which often result in delay or mortality from impingement on trash-racks or turbine passage. These problems can be mitigated with downstream passage solutions, such as angled racks that guide downstream-migrating eels to safe passage routes. The importance of bar spacing and phenotypic diversity for passage performance is, however, largely unknown. In this study, we investigated how morphological parameters (body mass, eye and fin indices) and behavioral score (open field test) influenced passage rate at an experimental intake equipped with a bypass and angled racks with either 15 or 30 mm bar spacing. Both racks were efficient in guiding eels into a bypass. There was a strong positive effect of body mass and a weak positive effect of open field test score on passage rate. Other factors such as eye and fin indices played a minor role. These results demonstrate the performance of angled racks with bypasses and form a useful starting point for further research regarding the relationships between individual variation in behavior, morphology and passage solutions for silver eels.

How natural are the forests in Rajiv Gandhi (Nagarhole) Tiger Reserve? A multi-source data approach.

This study aimed to monitor long-term land use dynamics for understanding the natural forestintegrity and intactness of the Rajiv Gandhi (Nagarhole) Tiger Reserve (RTR) pre- and post-declarations as TR. We employed multi-source data from Survey of India Toposheets (1:50k), Landsat-7, and Sentinel-2A along with Global Ecosystem Dynamics Investigation (GEDI) vegetation canopy height (10m) data, a high-spatial resolution CORONA (1970) images and temporal Google Earth Pro images for mapping and validation. To map vegetation type, land use and land cover (LULC) transitions, and fragmentation (1980-2022) we employed a hybrid classification approach. This study also analyzed decadal forest dynamics within TRsusing India's State of Forest Reports (ISFR). Findings reveal significant forest fragmentation and habitat loss due to anthropogenic activities in the TR. Mono-plantations (teak and eucalyptus) were found inside TR, while the buffer (1km) was occupied mainly with coffee and orange plantations which indicates the prevalence of human footprint. The overall accuracy of the current period (2022) is 92.0% with a kappa coefficient value of 0.90. These plantations were established during the British colonial period (early 1900s) for commercial purposes by clearing natural forests. The present study highlights that mono-plantations have not transitioned into natural forests even after a century. This lack of transformation could potentially compromise the integrity of the native forest. Despite its ecological significance, RTR has experienced disturbance due to human footprint. Hence, there is a need for an action plan to protect this vital landscape by replacing mono-plantations with suitable species to preserve the integrity of the forest. These issues extend beyond the protected areas, impacting surrounding regions and require regular monitoring. The proposed methods can be applied to other protected areas facing similar problems in the countryand world.

Empirical assessments of small-scale ecosystem service flows in rural mosaic landscapes in the Ethiopian highlands

Human activities have rapidly altered natural ecosystems worldwide, resulting in fragmented ecosystems that are either culturally or formally protected. These ecosystem patches can be critical for ecosystem services (ES) that support human well-being. In the Ethiopian highlands, the remaining church forests and wetlands have a unique conservation status and are part of the global priority areas for biodiversity conservation. ES flows from these ecosystems to surrounding benefiting areas lack local-scale field evidence data and are not well-understood. Here, we empirically quantify the distance-dependent flows for four ES: grass biomass, microclimate regulation, crop pollination, and soil erosion retention since they exhibit considerable variation in spatial scales and processes of ES flows. The effect of spatial distance on each ES benefit flow was analysed using spatially explicit empirical models. The key findings are as follows: (1) The benefit of ES varies significantly with distance to the source ecosystems. (2) ES supply is determined by the extent (fragmentation) and condition of ecosystems, together with ecosystem type. (3) The quantity and number of ES provided decreases with distance from the source, and beneficiaries up to 3 km of the source only receive one type of ES (grass biomass). Approximately 80 % of the benefiting areas are within a radius of 200 m from forests and wetlands. Bundles of multiple ES types are received at the frontiers of service-providing ecosystems, where number of benefits are compared at particular locations from the source point. The investigated ecosystems (440 km2) provided benefits to 8,770 km2 for the four types of ES. Our findings imply that non-linear effects of key ecosystem variables need to be considered when mapping the distance-dependent ES flows. This study helps to understand the spatial connectivity between ecosystems and beneficiaries in the human-nature interdependency, which is useful for developing different strategies for ES conservation.

Edge history modulates the depth of edge influence: Evidence from ground beetles with different feeding traits

Anthropogenic habitat loss and fragmentation are major concerns to conservationists, since these processes lead to species decline and extinction. Edge effect is one of the most important causes of biodiversity losses in fragmented habitats. The depth of edge influence, the distance over which the edge effect penetrates into the adjacent habitat is a central issue, as it fundamentally determines whether the habitat fragment has any remaining core habitat, which is essential for the survival of habitat specialist species. We reviewed 204 edge studies on ground beetles (Coleoptera: Carabidae) of different feeding habits, in forests, one of the habitats most impacted by humans. Meta-analysing 1814 abundance data of 351 ground beetle species from forest edges and their adjoining interiors, we showed that forest edges had significantly higher abundance of herbivorous, omnivorous, and predatory ground beetles than their interiors. Edge history considerably affected the depth of edge influence which on all trophic groups was similar in natural edges and those maintained by agriculture (≤ 10–20 m), while it was wider (> 300 m) when created by forestry or other anthropogenic activities. Consequently, the minimum area of a forest fragment should be ∼ 330 ha in order to keep half of it as core habitat to preserve forest-interior species.

Ghost roads and the destruction of Asia-Pacific tropical forests.

Roads are expanding at the fastest pace in human history. This is the case especially in biodiversity-rich tropical nations, where roads can result in forest loss and fragmentation, wildfires, illicit land invasions and negative societal effects1-5. Many roads are being constructed illegally or informally and do not appear on any existing road map6-10; the toll of such 'ghost roads' on ecosystems is poorly understood. Here we use around 7,000 h of effort by trained volunteers to map ghost roads across the tropical Asia-Pacific region, sampling 1.42 million plots, each 1 km2 in area. Our intensive sampling revealed a total of 1.37 million km of roads in our plots-from 3.0 to 6.6 times more roads than were found in leading datasets of roads globally. Across our study area, road building almost always preceded local forest loss, and road density was by far the strongest correlate11 of deforestation out of 38 potential biophysical and socioeconomic covariates. The relationship between road density and forest loss was nonlinear, with deforestation peaking soon after roads penetrate a landscape and then declining as roads multiply and remaining accessible forests largely disappear. Notably, after controlling for lower road density inside protected areas, we found that protected areas had only modest additional effects on preventing forest loss, implying that their most vital conservation function is limiting roads and road-related environmental disruption. Collectively, our findings suggest that burgeoning, poorly studied ghost roads are among the gravest of all direct threats to tropical forests.

Germination of aspidosperma discolor a. Dc. Under Different light and Temperature Conditions

Theoretical framework: Among the genera of the Apocynaceae family found in Brazil, Aspidosperma is among the most important, because of its high medicinal and economic value. Objective: The objective of this work was to evaluate the effects of white, far-red, and red light, and the absence of light; as well as the effects of constant temperatures of 25 ºC, 30 ºC and 35 ºC, on seed germination behavior of Aspidosperma discolor A. DC. Method: The material was collected in Atlantic Forest fragments. The germination percentage, speed index, average time and average seed germination speed were evaluated. A completely randomized design was used, and the means were compared by the Tukey test at 95% probability. A 4 x 2 factorial arrangement was used for the evaluation of the light regime (four light regimes and two origins); and for the thermal influence, a 3 x 2 arrangement (three temperature levels and two origins) was employed. Each test had five repetitions with 20 seeds. Results: The results showed that the seeds of both origins presented preferential or neutral photoblastic behavior, with better germination performance at 25 °C. However, they had total germination inhibition when exposed to 35 ºC.

EFFECT OF FUNCTIONAL STRATEGIES AND ABUNDANCE OF Acacia mangium Willd ON THE NUMBER OF NATIVE SPECIES IN A SECONDARY FOREST FRAGMENT IN SOUTHERN AMAPA, BRAZIL

Acacia mangium Willd is a fast-growing exotic tree that, when inserted in a different environment, can present an invasive potential in secondary forests. This study aimed to analyze the effect of abundance and functional strategies of A. mangium Willd and edaphic factors on native species richness in a secondary forest fragment located behind the Instituto Federal do Amapá campus Laranjal do Jari, Amapá. For this, all tree individuals with diameter at breast height (DBH) ≥ 10 cm occurring in 10
 plots of 200 m2 distributed in the fragment were identified. Soil samples were collected in the plots and sent for fertility and granulometry analysis. Three leaf functional attributes of individuals of A. mangium Willd occurring in the plots were measured: leaf area (LA), leaf thickness (LT) and specific leaf area (SLA). A total of 145 tree individuals and 14 species were sampled, with A. mangium Willd being the most abundant with 95 individuals. The relative abundance of A. mangium Willd was negatively related to native species richness in the fragment. The species also exhibited distinct leaf attributes and abundances according to the variation in soil acidity and fertility in the fragment, which influenced the number of native species. There is a need to develop monitoring and management of invasive exotic species such as A. mangium Willd in fragments of secondary forests, since the species is invasive and opportunistic, and can inhibit the regeneration of native species after local disturbances.

A multitaxa approach to biodiversity inventory in Matela protected area (Terceira, Azores, Portugal).

This manuscript is the first contribution of the project, "Matela - uma ilha de biodiversidade" ("Matela - an island of biodiversity"), that aims to restore the native vegetation within the Azorean Protected Area of the Terceira Island Nature Park known as the "Protected Area for the Management of Habitats or Species of Matela" (TER08), situated on Terceira Island, the Azores Archipelago, Portugal. This small fragment of native forest, positioned at a low-medium altitude (300-400 m a.s.l.), is facing some conservation impacts as a consequence of the spread of different invasive exotic plant species, mainly Pittosporumundulatum, Rubusulmifolius and Hedychiumgardnerianum. The database we present encompasses diverse taxonomic groups, including bryophytes, vascular plants, arthropods, birds and mammals. It is derived from intensive sampling campaigns conducted in 2022, but some data from a previous vascular plant survey in 2015 were also included. The objective of this study was to provide an updated inventory of bryophytes, vascular plants, arthropods, birds and mammals within this protected area. In this way we are providing the reference conditions necessary for the monitoring of the impacts of the current ongoing restoration efforts within the project "Matela - an island of biodiversity". Whenever feasible, the present inventory is juxtaposed with historical data from previous surveys conducted in Matela. In the realm of bryophytes, our analysis revealed the presence of 75 taxa, comprising 44 mosses and 32 liverworts. Amongst these, 71 were indigenous, while three remained indeterminate and one, Campylopusintroflexus, was identified as invasive. A comparison with previous historical data revealed a decrease in species richness, which was partially counterbalanced by the discovery of 23 new recorded species in the area.Regarding vascular plants, we distinguished 54 species, comprising 28 indigenous and 26 introduced taxa. Almost 80% of the inventoried species (n = 43) were newly documented in Matela.The study of arthropods encompassed a total of 103 taxa. Within the realm of soil arthropods, we documented eight indigenous and 25 introduced taxa, witnessing the disappearance of endemic species alongside a substantial increase in introduced ones between 2002 and 2022. Canopy arthropods, totalling 36 indigenous and 18 introduced taxa, exhibited few changes when compared with data from 2002. SLAM traps captured 24 indigenous and 15 introduced arthropod taxa and no historical data are available for comparison.As for avian species, we noted 12 indigenous birds and one introduced species, confirming the presence of most of the historical recorded native species.The mammalian census revealed eight introduced species, setting new precedents for Matela, alongside the identification of one endemic species: the Azorean endemic bat Nyctalusazoreum.

Safeguarding the last stronghold: Ecology and conservation of Asiatic Cheetah's prey species in Turan Biosphere Reserve (Iran)

Identifying suitable habitats for wild felids is essential for effective area-based conservation efforts. However, modeling habitat suitability for extremely rare and endangered taxa such as the Asiatic Cheetah (Acinonyx jubatus venaticus) is challenging due to limited data availability. To address this, our study focused on analysing the distribution factors of the Asiatic Cheetah's main prey species, including the Wild Goat (Capra aegagrus), Urial (Ovis vignei), Goitered Gazelle (Gazella subgutturosa), Jebeer Gazelle (Gazella bennettii), and Cape Hare (Lepus capensis) in the Turan Biosphere Reserve (TBR), a critical Cheetah habitat in Iran. To determine habitat suitability for these prey species, we conducted a systematic field survey along 30 transects measuring 16 km each by collecting data in each 1 km interval, resulting in 1172 direct observations of their presence. These observations were then correlated with 44 variables grouped into four categories: bioclimatic, topography, vegetation, and distance to anthropogenic and natural features. Suitability maps were generated using a hierarchical modeling approach. Among the observed prey species, Urial had the highest frequency of sightings (675 visual observations over eight seasons), followed by Goitered Gazelle (564 observations), Cape Hare (278 observations), Jebeer Gazelle (232 observations), and Wild Goat (208 observations). The most influential predictors affecting prey species distribution were mean summer temperature (with optimal ranges at lower temperatures), terrain relief roughness (with optimal ranges at intermediate roughness), distance to wells (with optimal ranges at shorter distances), and distance to corrals (with variable optimal ranges across species). Our findings indicate that the western and eastern mountainous areas, along with their hilly surroundings, as well as the northwest and western plains of TBR, constitute the most suitable habitats for these five prey species. These models and suitability maps provide crucial evidence for implementing conservation measures in the vulnerable habitats of the Asiatic Cheetah and its primary prey species. Environmental conditions can be enhanced through the management of water sources, roads, corrals, and livestock grazing. In addition, the fragmentation of suitable areas within TBR highlights the importance of preserving corridors between these fragmented habitats. We recommend re-evaluating and expanding the boundaries of Turan National Park, Turan Wildlife Refuge, and Turan Biosphere Reserve to ensure the long-term conservation of this threatened felid species and its associated ecosystems.

Landscape fragmentation constrains bumblebee nutritional ecology and foraging dynamics

Habitat fragmentation is modifying landscapes and the distribution of floral resources, possibly shaping pollinator resource acquisition, which is an issue of global concern for pollinator health and urbanization sustainability. Here, in different urban parks contrasting in terms of local features and surrounding urban matrix, we aimed to clarify how fragmentation and local flower availability shape bumblebee foraging dynamics by characterizing several components: the nutritional content and plant composition of collected pollen pellets, the trip length and the plant-nutrition association along a fragmentation gradient. We found mostly negative linear or non-linear relationships between nutritional quality and fragmentation, tight plant composition-nutrition associations interpretable as low access to alternative resources, and longer foraging time in smaller green areas, showing that urban green area fragmentation limits nutritional resource accessibility. However, flower local richness improved the collection of beneficial nutrients as proteins and polyphenols, thus potentially rescuing negative landscape effects. This study illuminates the link between landscape and local features and the nutritional ecology of pollinators, a key aspect for understanding pollinator foraging dynamics. The findings of the study can provide valuable guidelines for policy makers and stakeholders involved in the management and ecological restoration planning for urban green areas and even for outlining mitigation measures in urban contexts.

A satellite-field phenological bridging framework for characterizing community-level spring forest phenology using multi-scale satellite imagery

Forest phenology, as a sensitive indicator of a forest’s response to climate change and variability, has long been monitored using remote sensing, yet has seldom been interpreted or validated with spatially compatible, community-level field phenological observations. In temperate deciduous forests, multiple spring phenological phases are critical for modeling carbon storage and biogeochemical cycles. The simultaneous detection of all these critical phenological phases at the community level remains a long-standing challenge. To tackle these challenges, the objective of this study is to develop a novel satellite-field phenological bridging framework for characterizing all key spring phenological phases of a fragmented deciduous forest using multi-scale satellite time series. The framework consists of four key components: deep learning-based spatiotemporal image fusion, satellite-based forest phenology modeling, satellite-based forest phenological metric extraction, and field-based forest community phenological characterization. With the devised framework, we extract a total of 24 satellite phenological metrics of Trelease Woods, a forest fragment near Urbana, IL, USA. From weekly field phenological observations of 148 canopy trees of 15 common species of the forest community, we devise three summative field phenological indices to characterize community-level phenological states in spring. Under the satellite-field bridging framework, events during each key spring forest phenological phase (i.e., bud swell, budburst/leafing out, leaf expansion, and leaf maturity) are successfully detected using the fusion imagery (MAE from 1.1 to 2.9 days and bias from -2.4 to 1.5 days). However, the satellite detection of the earliest field events may be influenced by understory plants, soil background, and snow. The subsequent multi-scale, satellite phenological analysis underscores the importance of taking into account spatial scale and representation from both satellite and field phenological perspectives in building corresponding bridging relationships. Among the extracted pheno-metrics, bridging the threshold-based metrics to field phenological indices results in the highest accuracy (MAE less than 3 days and bias less than 2 days). The strong agreement among the field indices demonstrates the effectiveness of our field phenological surveying approach in generating community-wide forest phenological representation. Our study innovatively scales up the field phenological observations from the individual trees to the species to the community level, and the devised framework enables accurate retrieval of all key phenological events of community-wide, spring canopy development of the forest fragment.

Post-fire Pinus radiata invasion in a threatened biodiversity hotspot forest: A multi-scale remote sensing assessment

Biological invasions are one of the most relevant factors of biodiversity loss, especially after fire disturbances. Wildfires can accelerate invasions of fire-prone species, like Pinus radiata, and dramatically alter ecosystems. However, how to assess the main impacts of this invasion process on the composition, structure, and functionality of ecosystems, including the post-fire revegetation processes, has not been fully resolved. This study aimed to evaluate the impacts of P. radiata invasion on fire-damaged forest ecosystems using combined remote sensing and in situ data, focusing particularly on changes in biodiversity, ecosystem structure, and functionality. The recovery of forest leaf area index (LAI) and the fraction of photosynthetically active radiation (FPAR) were monitored using Sentinel-2 time series products. Then the pre- and post-fire native community composition and the relationships of invasion and biodiversity with biotic and abiotic components were characterized using structural equation modeling (SEM). The postfire P. radiata density was mapped to quantify invasion intensity in three burned native forest fragments using generalized additive modeling (GAM) regressions based on UAS multispectral data. Biophysical metrics indicate that all forest fragments impacted by high, medium-high, and medium-low severity fires achieved a partial recovery of their canopy. The SEM model showed that microtopographic features and vegetation height explain native species diversity under pre-fire conditions due to their close relationship with favorable microclimatic conditions for species establishment. Vegetation height determined the abundance of P. radiata in post-fire conditions, and it negatively impacted diversity by promoting the homogenization of vegetation cover and altering diversity patterns. The general composition and abundance metrics also showed a substantial modification associated with the heavy (significant) invasion of P. radiata species. Predictive mapping of P. radiata density showed high accuracies (R2 =0.73 and explained deviation of 80%). The maps depicted an intense concentration of the invasive tree with a mean density of 76,217 individuals per ha−1 and high invasion spots with more than 176,000 individuals per ha−1. The quantification of invasion and mapping is a fundamental input for prioritizing areas and resources for a large-scale restoration program, and is a priority to avoid the loss of these highly threatened forest ecosystems.

What are the key factors influencing the dynamics of forest edge? An application of a new forest edge index in the southeast of China

Recent reforestation programs have led to significant increases in forest cover in China; however, they have not been able to halt the process of forest fragmentation. The dynamics of forest fragmentation are still unknown, especially the transitions among forest core (FC), forest edge (FE), and non-forest areas. Taking Fujian Province in southeast China as a case, a new FE index (FEI) was proposed to identify FE, FC, forest patch (FP), matrix edge (ME), matrix core (MC), and forest perforation (FPe) as well. Then the transitions among FC, FE, and non-forest areas was explored; a series of logistic regression models were developed to examine the internal and external, static and dynamic driving patterns of the FE dynamics. The results revealed that the FEI outperforms conventional landscape metrics in identifying FE areas. During the period from 2000 to 2020, FE constituted approximately 41% of the study area. Frequent transition dynamics were observed between FE and other landscape types, accounting for 22% and 19% of the study area during 2000–2010 and 2010–2020, respectively. The internal driving models demonstrated that various landscape types exerted a negative influence on FE expansion. Among these, FPe emerged as a dominant factor, followed by MC, FC, and ME. The external models highlighted the significant influence of elevation, average annual temperature, distance from road, and slope on the mutual transition between FC and FE, while aspect and GDP influenced greatly on the transition from matrix to FE. These findings deepen the understanding of forest fragmentation dynamics and provide valuable insights for forest management.

Forest habitat loss and human land use alter predation of artificial ground nests

Anthropogenic disturbances including forestry, urbanisation and agricultural expansion are causing significant habitat loss and fragmentation in boreal forests, leading to changes in ecosystem function. Here, we ask whether these anthropogenic disturbances alter predator–prey spatial overlap in the boreal forest landscape, leading to increased nest predation rates on ground-nesting birds such as forest grouse. To study the roles of forest loss and fragmentation on nest survival, we conducted an artificial nest predation experiment in Finland using 370 camera traps across landscapes varying in forest quantity and fragmentation (measured by edge habitat length). Our artificial nests mimicked the early egg-laying stage of forest grouse. Our primary hypotheses were that nest survival is higher in landscapes with more continuous forest habitat and less edge habitat, and that predator communities differ based on the matrix habitat between the forests. Our findings revealed a negative association with forest cover and nest predation risk, but forest fragmentation, measured as edge length, had no detectable relationship with the nest predation risk. Additionally, nest predation risk depended on the matrix habitat types, with agricultural land and urban areas exhibiting higher predation rates than clearcuts exhibited. Furthermore, the number of predator species observed was positively associated with the level of urban area present. We found that the raccoon dog (Nyctereutes procyonoides), a rather novel invasive alien species, was the most common mammalian nest predator, indicating a change in the predator community. Our results highlight the possible impact of both forest loss and the presence of agricultural and urban areas in the landscape on avian nest survival in forest habitats. We conclude that forest loss may be a more important factor affecting nest predation risk than forest fragmentation.

Species Diversity and Habitat Fragmentation Per Se: The Influence of Local Extinctions and Species Clustering.

AbstractAnthropogenic fragmentation of habitat is considered to be a critical factor contributing to the decline of species. However, a general consensus on the degree to which habitat loss and what has been called "habitat fragmentation per se" contribute to the loss of species diversity has not yet emerged. For empirical and theoretical reasons the topic has recently attracted renewed attention, thus reviving the "single large or several small" (SLOSS) debate. To study the effect of fragmentation per se, we use a spatially explicit and continuous, competitively neutral simulation model with immigration from a regional pool. The model accounts for the influence of ecological drift and intrafragment species clustering (due to limited dispersal) on local (plot) and global (landscape) diversity. We find that fragmentation increases global diversity but decreases local diversity, prominently so if fragments become more isolated. Cluster formation is a key mechanism reducing local diversity. By adding external disturbance events that lead to the occasional extinction of entire communities in habitat fragments, we show that the combined effect of such extinctions and cluster formation can create nonlinear interactive effects of fragmentation and fragment isolation on diversity patterns. We conclude that while in most cases fragmentation will decrease local and increase landscape diversity, universal predictions concerning the SLOSS debate should be taken with care.