Fragmentation impacts may be mixed for conservation but generally bad for restoration

Restoration Ecology, Journal Year: 2024, Volume and Issue: 32(8)

Published: Aug. 19, 2024

The influence of fragmentation per se on biodiversity is hotly debated, with evidence negative, neutral, or even positive effects after controlling for habitat amount. Principles from this debate are often used to inform conservation in remnant fragments but rarely considered a restoration context. Habitat essential work alongside and reverse declines. Although restored habitats vary along similar gradient patches, the importance different processes likely varies. Communities patches largely determined by existing populations, while communities shaped colonization nearby populations. We illustrate how can have variable outcomes depending whether conserved restored. debate, its current form, has limited application ecology, we emphasize need ecologists conservationists consider directionality process.

Language: Английский

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Habitat edges decrease plant reproductive output in fragmented landscapes

Journal of Ecology, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 27, 2024

Abstract Habitat loss is a major threat to biodiversity, but the effects of habitat fragmentation are less clear. Examining drivers key demographic processes, such as reproduction, will clarify species‐level responses and broader on biodiversity. Yet, understanding how affects demography has been challenging due many ways landscapes altered by co‐occurring fragmentation, coupled with rarity experiments disentangle these effects. In large, replicated experiment open savanna habitats surrounded pine plantation forests, we tested inter‐patch connectivity, patch edge‐to‐area ratio, within‐patch distance from an edge plant reproductive output. Using five experimentally planted species restoration interest—three wind‐pollinated grass two insect‐pollinated forb species—we measured flowering, pollination rate, seed production. All were more likely flower produce flowering structures farther forest edge. Connectivity edge, however, had no effect rate (regardless mode). Despite influence pollination, production increased for four species, driven increase in Synthesis . Altogether, demonstrate that output (seed production) decreased through flowering. Our work provides evidence important contributor demography, output, fragmented patches. These impacts may provide insight into mechanisms community‐level changes

Language: Английский

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Relationships between amount and configuration indicators in real-world landscapes: Novel references for the assessment of forest cover in the Iberian Peninsula

Ecological Indicators, Journal Year: 2024, Volume and Issue: 159, P. 111634 - 111634

Published: Jan. 28, 2024

Understanding the role of habitat loss and fragmentation per se is crucial to generate relevant knowledge for management. In case forest species, this can be achieved by measuring amount configuration metrics at landscape scale, including their relationship. We aimed characterize relationship between in real-world landscapes an extensive area, identifying thresholds that discriminate among levels. also investigated whether ecological political contexts could affect strength comprehensively analyzed cover Iberian Peninsula (20.56 million ha, year 2,018). calculated Forest Area Density (FAD) three employing a moving-window procedure. From metrics' surfaces we derived bivariate probability-density scatterplots, synoptic Fragmentation Level indicator (FL) subsequent classification correlation analyses. For Number Patches Edge (ED) maximum values variability appeared FAD 20% 50%, respectively. The extreme relative FL were 89% 55%, potentially representing extinction generic species. Major differences Portugal Spain found ED Mediterranean Ecoregions, being wildfire regimes ownership patterns plausible explanations. provide insights into references valuable identify areas concern management conservation region, as well foundation further research on responses fragmentation.

Language: Английский

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Genetic connectivity is maintained in two insect pollinators across a human‐altered landscape

Insect Conservation and Diversity, Journal Year: 2024, Volume and Issue: 17(4), P. 601 - 615

Published: Feb. 26, 2024

Abstract Population genetics is a valuable tool for assessing the impact of human‐altered landscapes on genetic connectivity in various species. However, when applied to insects, challenges arise due potentially large effective population sizes (), high dispersal capacities and recency anthropogenic impacts. This study assessed structure two pollinators across landscape Luxembourg. Samples from ashy mining bee ( Andrena cineraria , N = 201) greater fly Bombylius major, 637) were genotyped at 25 microsatellite loci, including genotyping‐by‐amplicon‐sequencing approach A. . Despite statistical power > 0.002 B. major 0.0025 no deviations homogeneity detected. For both species, there was evidence isolation‐by‐distance or clustering. Genetic most likely result levels gene flow that compensate effects drift. Estimates ranged between several thousand tens thousands, although precision low. Simulations highlighted lag times can substantially affect our ability detect recent (<50 generations) differentiation very large. Lag shorter with data 25,000 simulated di‐allelic but only sample remained high. Insect studies should consider ensure size markers offer adequate reject null hypothesis effect connectivity.

Language: Английский

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Habitat loss weakens the positive relationship between grassland plant richness and above-ground biomass

Published: Feb. 27, 2024

Habitat loss and fragmentation per se have been shown to be a major threat global biodiversity ecosystem function. However, little is known about how habitat alters the relationship between function (BEF relationship) in natural landscape context. Based on 130 landscapes identified by stratified random sampling agro-pastoral ecotone of northern China, we investigated effects context (habitat se) plant richness, above-ground biomass, them grassland communities using structural equation model. We found that directly decreased richness hence while increased biomass. Fragmentation also soil water content Meanwhile, magnitude positive biomass reducing percentage specialists community, had no significant modulating effect this relationship. These results demonstrate inconsistent function, with BEF being modulated Our findings emphasise rather than can weaken decreasing degree specialisation community.BEF moderated fragmented landscapes.Habitat effects.Habitat via community.

Language: Английский

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