Small habitat patches have been historically neglected in conservation, primarily because extinction risk is higher in small patches. Nevertheless, sets of small patches usually harbor more species ...than one or a few larger patches of equal total area. Resolving this inconsistency is key to policy and practice in biodiversity conservation. Our analysis of 32 datasets (603 patches and 2290 taxa) provides two novel lines of evidence confirming that small patches have disproportionately high value for biodiversity. First, sets of small patches harbor more species than large patches even when considering only species of conservation concern. Second, sets of small patches harbor more species than large patches even when the small patches are very small compared to the large patches. Therefore, higher extinction risk in small than large patches does not decrease the cumulative value of small patches for biodiversity. We contend that acknowledging the conservation value of small patches, even very small patches, will be a necessary step for stemming biodiversity loss in the Anthropocene.
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FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Emphasis has been put in recent ecological research on investigating phylogenetic, functional and taxonomic facets of biological diversity. While a flourishing number of indices have been proposed ...for assessing functional diversity, surprisingly few options are available to characterize functional rarity. Functional rarity can play a key role in community and ecosystem dynamics. We introduce here the funrar R package to quantify functional rarity based on species trait differences and species frequencies at local and regional scales. Because of the increasing availability of big datasets in macroecology and biogeography, we optimized funrar to work with large datasets of thousands of species and sites. We illustrate the use of the package to investigate the functional rarity of North and Central American mammals.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NMLJ, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Global biodiversity is facing a crisis, which must be solved through effective policies and on‐the‐ground conservation. But governments, NGOs, and scientists need reliable indicators to guide ...research, conservation actions, and policy decisions. Developing reliable indicators is challenging because the data underlying those tools is incomplete and biased. For example, the Living Planet Index tracks the changing status of global vertebrate biodiversity, but taxonomic, geographic and temporal gaps and biases are present in the aggregated data used to calculate trends. However, without a basis for real‐world comparison, there is no way to directly assess an indicator's accuracy or reliability. Instead, a modelling approach can be used. We developed a model of trend reliability, using simulated datasets as stand‐ins for the “real world”, degraded samples as stand‐ins for indicator datasets (e.g., the Living Planet Database), and a distance measure to quantify reliability by comparing partially sampled to fully sampled trends. The model revealed that the proportion of species represented in the database is not always indicative of trend reliability. Important factors are the number and length of time series, as well as their mean growth rates and variance in their growth rates, both within and between time series. We found that many trends in the Living Planet Index need more data to be considered reliable, particularly trends across the global south. In general, bird trends are the most reliable, while reptile and amphibian trends are most in need of additional data. We simulated three different solutions for reducing data deficiency, and found that collating existing data (where available) is the most efficient way to improve trend reliability, whereas revisiting previously studied populations is a quick and efficient way to improve trend reliability until new long‐term studies can be completed and made available.
Global biodiversity indicators provide vital information about the changing state of global biodiversity to guide research, conservation actions, and policy decisions. However, little is known about how gaps and biases in the underlying data affect their accuracy or reliability. We developed a model of trend accuracy based on properties of biodiversity time series data and used it to quantitatively assess the reliability of trends in the Living Planet Index. Our results suggest that many trends need more data to be considered reliable, particularly reptile and amphibian trends, and trends across the global south.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Efficient management of biodiversity requires a forward‐looking approach based on scenarios that explore biodiversity changes under future environmental conditions. A number of ecological models have ...been proposed over the last decades to develop these biodiversity scenarios. Novel modelling approaches with strong theoretical foundation now offer the possibility to integrate key ecological and evolutionary processes that shape species distribution and community structure. Although biodiversity is affected by multiple threats, most studies addressing the effects of future environmental changes on biodiversity focus on a single threat only. We examined the studies published during the last 25 years that developed scenarios to predict future biodiversity changes based on climate, land‐use and land‐cover change projections. We found that biodiversity scenarios mostly focus on the future impacts of climate change and largely neglect changes in land use and land cover. The emphasis on climate change impacts has increased over time and has now reached a maximum. Yet, the direct destruction and degradation of habitats through land‐use and land‐cover changes are among the most significant and immediate threats to biodiversity. We argue that the current state of integration between ecological and land system sciences is leading to biased estimation of actual risks and therefore constrains the implementation of forward‐looking policy responses to biodiversity decline. We suggest research directions at the crossroads between ecological and environmental sciences to face the challenge of developing interoperable and plausible projections of future environmental changes and to anticipate the full range of their potential impacts on biodiversity. An intergovernmental platform is needed to stimulate such collaborative research efforts and to emphasize the societal and political relevance of taking up this challenge.
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Tropical agroforestry systems provide farmers with resources for their livelihoods, but are also well‐recognized as refuges for biodiversity. However, the relationship between yield and biodiversity ...might be negative in these systems, reflecting a potential trade‐off between managing for increased yield or biodiversity. The potential for synergies will depend partly on the shape of the biodiversity–yield relationship, where a concave relationship suggests a faster decline in biodiversity with increasing yields than a linear or convex shape.
We studied the relationship between biodiversity (plant species richness and composition) and coffee yield along a gradient of management in south‐western Ethiopia, coffee's native range. We inventoried species richness and community composition of woody plants, herbaceous plants and bryophytes at 60 sites. We also measured coffee management‐related variables and assessed coffee yield for 3 consecutive years at each site.
Species richness of woody plants had a concave relationship with coffee yield, that is, tree richness declined fast initially before levelling out at higher yields, whereas there was no relationship between coffee yield and species richness of herbaceous plants or bryophytes. Species composition of woody plants, herbaceous plants and bryophytes all had a concave relationship with coffee yield.
From a methodological perspective, we found that multi‐year data on yield were necessary to reliably assess the relationship between biodiversity and yield, and that the number of coffee shrubs or coffee dominance were poor proxies for yield when trying to capture the biodiversity–yield relationship.
Synthesis and applications. The concave relationship between biodiversity components (species richness and composition) and yield suggests that there is a strong conflict between the goals of increasing production and conserving biodiversity. However, it is important to recognize that this pattern is largely driven by the very low‐yielding sites in natural forests. Here, even minor intensification of coffee management seems to rapidly erode biodiversity. Along the rest of the productivity gradient, there was generally no negative relationship between yield and biodiversity, implying opportunities for developing strategies for increasing yields without biodiversity loss.
The concave relationship between biodiversity components (species richness and composition) and yield suggests that there is a strong conflict between the goals of increasing production and conserving biodiversity. However, it is important to recognize that this pattern is largely driven by the very low‐yielding sites in natural forests. Here, even minor intensification of coffee management seems to rapidly erode biodiversity. Along the rest of the productivity gradient, there was generally no negative relationship between yield and biodiversity, implying opportunities for developing strategies for increasing yields without biodiversity loss.
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Aim
Many conservation efforts now focus on mitigating biodiversity loss due to climate change. While a focus on impacts from mean, long‐term changes in climate is warranted, the vast majority of ...conservation plans largely ignore another key factor of climate change—changes in the frequency and intensity of extreme weather and climate events. A typology of the full range and severity of ecological responses to extreme events would help underpin tracking of their impacts.
Location
Global.
Methods
Here, we review 519 observational studies of ecological responses to extreme events between 1941 and 2015. We include responses from amphibians, birds, fish, invertebrates, mammals, plants and reptiles to cyclones, drought, flood, cold waves and heat waves.
Results
Negative ecological responses were the most commonly reported, accounting for 57% of all documented responses. There were over 100 cases of a >25% population decline and 31 cases of local extirpation. Sixty per cent of the studies in our review observed ecological responses for more than 1 year, and of the studies that monitored species or ecosystem recovery following exposure to an extreme event, 38% showed species or ecosystems did not recover to pre‐disturbance levels.
Main conclusions
Extreme weather and climate events have profound implications for species and ecosystem management. We discuss current conceptual challenges associated with incorporating extreme events into conservation planning efforts, which include how to quantify species sensitivity and adaptive capacity to extreme events, how to account for interactions between extreme events and other stressors, and how to maximize adaptive capacity to more frequent and intense extreme events.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NMLJ, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
1. Cities are rapidly expanding world-wide and there is an increasing urgency to protect urban biodiversity, principally through the provision of suitable habitat, most of which is in urban green ...spaces. Despite this, clear guidelines of how to reverse biodiversity loss or increase it within a given urban green space is lacking. 2. We examined the taxa- and species-specific responses of five taxonomically and functionally diverse animal groups to three key attributes of urban green space vegetation that drive habitat quality and can be manipulated over time: the density of large native trees, volume of understorey vegetation and percentage of native vegetation. 3. Using multi-species occupancy-detection models, we found marked differences in the effect of these vegetation attributes on bats, birds, bees, beetles and bugs. At the taxa-level, increasing the volume of understorey vegetation and percentage of native vegetation had uniformly positive effects. We found 30-120% higher occupancy for bats, native birds, beetles and bugs with an increase in understorey volume from 10% to 30%, and 10-140% higher occupancy across all native taxa with an increase in the proportion of native vegetation from 10% to 30%. However, increasing the density of large native trees had a mostly neutral effect. At the species-specific level, the majority of native species responded strongly and positively to increasing understorey volume and native vegetation, whereas exotic bird species had a neutral response. 4. Synthesis and applications. We found the probability of occupancy of most species examined was substantially reduced in urban green spaces with sparse understorey vegetation and few native plants. Our findings provide evidence that increasing understorey cover and native plantings in urban green spaces can improve biodiversity outcomes. Redressing the dominance of simplified and exotic vegetation present in urban landscapes with an increase in understorey vegetation volume and percentage of native vegetation will benefit a broad array of biodiversity.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Belowground biodiversity supports multiple ecosystem functions and services that humans rely on. However, there is a dearth of studies exploring the determinants of the biodiversity–ecosystem ...function (BEF) relationships, particularly in intensely managed agricultural ecosystems. Here, we reported significant and positive relationships between soil biodiversity of multiple organism groups and multiple ecosystem functions in 228 agricultural fields, relating to crop yield, nutrient provisioning, element cycling, and pathogen control. The relationships were influenced by the types of organisms that soil phylotypes with larger sizes or at higher trophic levels, for example, invertebrates or protist predators, appeared to exhibit weaker or no BEF relationships when compared to those with smaller sizes or at lower trophic levels, for example, archaea, bacteria, fungi, and protist phototrophs. Particularly, we highlighted the role of soil network complexity, reflected by co‐occurrence patterns among multitrophic‐level organisms, in enhancing the link between soil biodiversity and ecosystem functions. Our results represent a significant advance in forecasting the impacts of belowground multitrophic organisms on ecosystem functions in agricultural systems, and suggest that soil multitrophic network complexity should be considered a key factor in enhancing ecosystem productivity and sustainability under land‐use intensification.
We reported significant and positive relationships between soil biodiversity of multiple organism groups and multiple ecosystem functions in 228 agricultural fields, relating to crop yield, nutrient provisioning, element cycling, and pathogen control. The relationships were influenced by the types of organisms, that soil phylotypes with larger sizes or at higher trophic levels appeared to exhibit weaker or no BEF relationships when compared to those with smaller sizes or at lower trophic levels. Particularly, the results highlighted the role of soil network complexity, reflected by co‐occurrence patterns among multitrophic‐level organisms, in enhancing the link between soil biodiversity and ecosystem functions.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Debate about what proportion of the Earth to protect often overshadows the question of how nature should be conserved and by whom. We present a systematic review and narrative synthesis of 169 ...publications investigating how different forms of governance influence conservation outcomes, paying particular attention to the role played by Indigenous peoples and local communities. We find a stark contrast between the outcomes produced by externally controlled conservation, and those produced by locally controlled efforts. Crucially, most studies presenting positive outcomes for both well-being and conservation come from cases where Indigenous peoples and local communities play a central role, such as when they have substantial influence over decision making or when local institutions regulating tenure form a recognized part of governance. In contrast, when interventions are controlled by external organizations and involve strategies to change local practices and supersede customary institutions, they tend to result in relatively ineffective conservation at the same time as producing negative social outcomes. Our findings suggest that equitable conservation, which empowers and supports the environmental stewardship of Indigenous peoples and local communities represents the primary pathway to effective long-term conservation of biodiversity, particularly when upheld in wider law and policy. Whether for protected areas in biodiversity hotspots or restoration of highly modified ecosystems, whether involving highly traditional or diverse and dynamic local communities, conservation can become more effective through an increased focus on governance type and quality, and fostering solutions that reinforce the role, capacity, and rights of Indigenous peoples and local communities. We detail how to enact progressive governance transitions through recommendations for conservation policy, with immediate relevance for how to achieve the next decade's conservation targets under the UN Convention on Biological Diversity.
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