Dimensions Of Biodiversity Research Articles

Consideration of Multitrophic Biodiversity and Ecosystem Functions Improves Indices on River Ecological Status.

Biological quality elements have been developed worldwide to assess whether a water body is in a good status or not. However, current studies mainly focus on a single taxonomic group or a small set of species, often limited by methods of morphological identification, and lack further aspects of biodiversity (e.g., across taxa and multiple attributes) and ecosystem functions. Here, we advance a framework for assessing the river's ecological status based on complete biodiversity data measured by environmental DNA (eDNA) metabarcoding and measurements of ecosystem functions in addition to physicochemical elements across a large riverine system in China. We identified 40 indicators of biodiversity and ecosystem functions, covering five taxonomic groups from bacteria to invertebrates, and associated with multiple attributes of biodiversity and ecosystem functions. Our data show that human impact on ecosystems could be accurately predicted by these eDNA-based indicators and ecosystem functions, using cross-validation with a known stressor gradient. Moreover, indices based on these indicators of biodiversity and ecosystem functions not only distinguish the physicochemical characteristics of the sites but also improve the assessment accuracy of 20-30% for the river's ecological status. Overall, by incorporating eDNA-based biodiversity with physicochemical and ecosystem functional elements, the multidimensional perspectives of ecosystem states provide additional information to protect and maintain a good ecological status of rivers.

Selection on convergent functional traits drives compositional divergence in early succession of a tallgrass prairie restoration experiment

Abstract Plant biodiversity is often partitioned into taxonomic diversity (species composition and abundance), phylogenetic diversity (breadth of evolutionary lineages) and functional diversity (resource‐use strategies or physical traits). Evaluating the effects and interplay of these dimensions can provide insights into how assembly processes drive compositional changes in plant communities. However, teasing apart the effects of different biodiversity dimensions is challenging in observational studies or retrospective analyses. To evaluate how plant phylogenetic and trait history shape community establishment and turnover in restoration of a species‐rich North American tallgrass prairie, we conducted an experiment with 127 species planted in assemblages representing three levels of phylogenetic diversity (PD) and two of functional trait diversity (FD), holding starting species richness (SR) fixed. We tested whether PD and FD of planted assemblages predicted species diversity, compositional turnover and selection on functional traits. Rank order of initial functional and phylogenetic diversity levels was maintained throughout the experiment, but neither diversity measure correlated positively with species richness by the end of the experiment. Phylogenetic and taxonomic beta diversity increased among all treatments. This increase in compositional beta diversity was associated with directional selection on phylogenetically dispersed functional traits. A set of functional traits associated with competitiveness in tallgrass prairies predicted species' cover for all survey years: stem dry matter content, leaf dry matter content, vegetative height and rhizomatous growth. Although all plots collectively converged on a similar suite of functional traits, functional beta diversity increased among high‐FD plots. Synthesis. Neither higher functional nor phylogenetic diversity maintained higher species richness (SR) over time in our study. Although SR was not maintained, higher levels of PD and FD were. Both types of diversity shaped the rate at which plots changed in composition over time, with high diversity treatment plots increasing in beta diversity. Selection for traits convergent across the tree of life drove phylogenetic and compositional divergence among plots. While optimization of site‐specific functional traits may be most important for maintaining higher SR, our work implies that planting higher initial PD and FD may make grassland restorations more adaptable to site conditions that may be difficult to predict.

Taxonomic, functional and phylogenetic bird diversity response to coffee farming intensity along an elevational gradient in Costa Rica

The expansion of the agricultural frontier in the species-rich tropical regions of the world has generated conflicts between the need to secure food production and the conservation of biodiversity. As natural areas give way to farmlands, the future of sensitive taxa may depend on how intensively the crops are cultivated. In order to better understand the response of avian diversity to cultivation intensity in tropical farmlands, analyses of species richness are increasingly being complemented with information about the birds’ functional roles and evolutionary history. In this study, we analysed the association of several features of vegetation composition and structure, as indicators of cultivation intensity in coffee farms in Costa Rica, on the taxonomic, functional and phylogenetic dimensions of avian biodiversity at the local scale across an approximately 2000 m elevational gradient. Bird detections and vegetation measurements were conducted at 120 randomly selected circular plots of 25 m radius, across 51 coffee farms. Using regression modelling and multi-model inference, we related six vegetation features to five biodiversity metrics in this system and evaluated whether the results differed among elevational zones. The most influential vegetation feature was the number of trees with a diameter-at-breast-height larger than 30 cm, promoting higher richness, functional redundancy and phylogenetic structure of avian species. Shade from canopy cover and the number of non-coffee crops increased species and phylogenetic richness, respectively. The effect of individual vegetation features on particular biodiversity metrics varied across elevation, possibly due to the idiosyncratic response of each dimension to the elevation gradient or because of local ecological processes. We conclude that vegetation features related to cultivation intensity have effects on avian diversity, but that these effects differ among biodiversity metrics and are sensitive to the environmental context. Consequently, targeted conservation management should be based on more comprehensive studies that include more than one biodiversity dimensions as well as variation in relevant environmental context. In general, our results suggest that, when designing conservation strategies for birds in coffee-dominated landscapes, there is likely no “one-size-fits-all” strategy.

Conservation hotspots of insular endemic mammalian diversity at risk of extinction across a multidimensional approach

AbstractAimIslands are one of the most threatened worldwide biotas. Based on their taxonomic diversity, some insular regions have been identified as key areas of conservation. Recently, systematic conservation planning has advocated for the use of multiple biodiversity facets to protect unique evolutionary and functional processes. Here, we identified priority areas for threatened insular endemic mammals across three key dimensions of biodiversity (taxonomic, phylogenetic, and functional), as well as their protection level and threats affecting them.LocationWorldwide.MethodsWe applied diversity–area relationships to identify insular regions that harbored a disproportionately high rate of threatened endemic mammal diversity (whether taxonomic, phylogenetic, or functional) given their area for 1,799 islands across 19 insular regions. We also assessed the level of protection and the threats affecting biodiversity within each insular region.ResultsWe showed a fairly good congruence between top‐ranked insular regions based on taxonomic, phylogenetic, and functional diversity. Specifically, we identified four hotspots for endemic mammalian conservation through the three diversity facets: Indo‐Burma, Madagascar and the Indian Ocean Islands, Mesoamerica and Galápagos Islands, and Wallacea. Except for Mesoamerica and Galápagos Islands, the protected areas coverage is low (<8%) within the hotspots. We also showed that most of the mammal species occurring in the hotspots was prone to either direct threats that affect their mortality or indirect threats that only alter their habitat, while mixed threats such as biological invasions or climate change were less represented in those regions.Main conclusionsOur findings reinforce the importance of investigating the multiple diversity facets in a conservation concern and to link with the associated threats to ensure an effective conservation strategy.

Biodiversity scale‐dependence and opposing multi‐level correlations underlie differences among taxonomic, phylogenetic and functional diversity

AbstractAimBiodiversity is a multi‐dimensional property of biological communities that represents different information depending on how it is measured, but how dimensions relate to one another and under what conditions is not well understood. We explore how taxonomic, phylogenetic, and functional diversity can differ in scale‐of‐effect dependence and habitat‐biodiversity relationships, and subsequently how spatial differences among biodiversity dimensions may arise.LocationNebraska, United States.TaxonBirds.MethodsAcross 2016 and 2017, we conducted 2,641 point counts at 781 sites. We modeled the occupancy of 141 species using Bayesian Bernoulli‐Bernoulli hierarchical logistic regressions. We calculated species richness (SR), phylogenetic diversity (PD) and functional diversity (FD) for each site and year based on predicted occupancy, accounting for imperfect detection. Using Bayesian latent indicator scale selection and multivariate modeling, we quantified the spatial scales‐of‐effect that best explained the relationships between environmental characteristics and SR, PD and FD. Additionally, we decomposed the residual between‐site and within‐site biodiversity correlations using our repeated measures design.ResultsAlthough relationships between specific land cover types and SR, PD and FD were qualitatively similar, the spatial scales at which these variables were important in explaining biodiversity differed among dimensions. Between‐site residual biodiversity correlations were negative, yet within‐site biodiversity residual correlations were positive.Main conclusionsOur results demonstrate how spatial differences among biodiversity dimensions may arise from biodiversity‐specific scale‐dependent habitat relationships, low shared environmental correlations and opposing residual correlations between dimensions, suggesting that single‐scale and single‐dimension analyses are not entirely appropriate for quantifying habitat‐biodiversity relationships. After accounting for shared habitat relationships, we found positive within‐site residual correlations between SR, PD and FD, suggesting that habitat change over time influenced all biodiversity dimensions similarly. However, negative between‐site residual correlation among biodiversity dimensions may indicate trade‐offs in achieving maximum biodiversity across multiple biodiversity dimensions at any given location.

Evidence-based alignment of conservation policies with remote sensing-enabled essential biodiversity variables

Nature conservation policies require up-to-date and accurate biodiversity monitoring. Innovative synoptic information products such as Remote Sensing-enabled Essential Biodiversity Variables (RS-enabled EBVs) could complement field observations in biodiversity monitoring. It is not clear however, how these scientific remote sensing products can be utilized for policy reporting. Agreement on the monitored geographic extent (area size and scale), as well as biodiversity attributes (composition, structure, and function), may provide a common'point of departure' for policymakers and the scientific community to develop and further improve monitoring. In this study, biodiversity indicators of 10 nature conservation policies and 50 RS-enabled EBVs were compared using non-parametric tests (chi-square and Mann-Whitney U). Our main finding is that policy indicators and RS-enabled EBVs are very similar in the spatial extent they address (mapping scale). However, most policy indicators are related to ecosystem structure while most of the RS-enabled EBVs are related to ecosystem function and ecosystem structure. RS-enabled EBVs have added value in monitoring of biodiversity, especially when looking at ecosystem functioning. Information on ecosystem functioning and structure provides evidence needed as input for policy development and management of biodiversity. However, to make this happen, a stronger focus on ecosystem functioning and structure with appropriate variables is needed, in policy requirements and targets.

Geographic patterns and climate correlates of the deviation between phylogenetic and taxonomic diversity for angiosperms in China

Taxonomic diversity (TD) of areas within a region is often strongly and positively correlated with phylogenetic diversity (PD) of the areas. However, variation in speciation and extinction rates and the biogeographic histories of lineages can result in significant deviation of PD from TD (i.e., relative PD after correcting for TD; hereafter PDdev). Identifying areas with higher or lower PDdev within a region is important not only to understanding evolutionary processes associated with the causes of biodiversity patterns across the region but also to identifying areas to be protected for different dimensions of biodiversity. Here, we contrast geographic distributions of PD versus TD for angiosperms in China, explore geographic patterns of PDdev, identify areas where PD is much higher (hotspots) or much lower (coldspots) than expected based on TD, and relate the three diversity metrics to climate variables. We found that geographic patterns of TD were highly congruent with those of PD but they were incongruent with those of PDdev. Areas of unusually high PDdev were generally not those of high TD and PD. Biodiversity hotspots identified based on PDdev generally did not overlap with those identified based on TD and PD. We suggest that identifying areas to be protected should consider not only areas of high TD and PD but also areas of unusually high PDdev, because areas of high PDdev likely hold ancient evolutionary histories and uniqueness, and these areas may not overlap with those having high TD and PD.

Within‐corridor heterogeneity is more important than corridor design for maintaining butterfly functional and taxonomic diversity

Abstract Local and landscape features influence the spatial distribution of biodiversity. At the landscape scale, heterogeneity has compositional and configurational components that can be measured at different resolutions of conservation planning. We assess the importance of local and landscape features measured at different planning resolutions for maintaining taxonomic and functional butterfly diversity. In remnant conservation corridors that dissect alien tree plantations, butterflies were sampled along a gradient of successional stages, from open and recently burned grasslands to closed‐canopy woody habitats. Changes in local vegetation structure were represented by measures of canopy cover. At the landscape scale, compositional and configurational heterogeneity were measured at two resolutions: a simple binary classification of suitable habitat versus unsuitable transformed habitat, and a classification that accounts for the different successional stages within corridors (i.e. within‐corridor heterogeneity). Butterfly assemblages were characterized using taxonomic (Simpson's diversity index) and functional indices (Rao's quadratic entropy). The relationship between environmental filters and species traits was further assessed using multivariate modelling. Taxonomic diversity did not reflect functional diversity, as the latter showed differential trait specific responses to local vegetation structure. For both functional and taxonomic diversity, local and landscape variables representing within‐corridor heterogeneity were more important than landscape variables measured at the coarser planning resolution. Butterfly diversity showed a negative relationship with increasing edge density between grassy and woody habitats. Synthesis and applications. To promote the taxonomic and functional dimensions of biodiversity, management should aim to maintain both open‐ and closed‐canopy habitats within corridors. These habitats should be contiguous, and corridors as wide as possible, to increase the patch size of contiguous habitat while reducing the proportion of edge.

Weaving Indigenous and Western Science Knowledges Through a Land-Based Field Course at Bkejwanong Territory (Laurentian Great Lakes)

In response to a growing interest in building Indigenous-led educational experiences, we codeveloped a land-based field course that wove Indigenous ways of knowing together with Western ecological concepts. The spirit of the course was the one rooted in varied ways of knowing nature, on the land, the water, and the culture—to see the Great Lakes from an Anishinaabe perspective. Situated in the heart of the Laurentian Great Lakes Basin at Bkejwanong Territory (Walpole Island First Nation), in the Traditional Territory of the Three Fires Confederacy of First Nations (Ojibwe, Odawa, and Potawatomi) on Turtle Island (North America), this inaugural undergraduate university course was led by an Indigenous instructor with contributions from non-Indigenous science faculty from the university and local community knowledge keepers. Here, we describe our journey in cocreating land-based teaching modules with Indigenous scholars and scholars at the University of Windsor, Ontario, Canada. We focused on experiences that exposed students to traditional ways of knowing nature, and reflections were used as the main teaching pedagogy. The course offered daily perspectives and activities across land and water and examined dimensions of biodiversity as sacred beings and medicine. Outcomes and indicators of success were driven by the individual’s reflection and evaluation on their own growth, as expressed through a final project aimed at bridging knowledges, supporting community initiatives or both. This case is designed to offer an example that has potential for application to many other contexts where community-faculty partnerships and land-based learning opportunities are available.

Three dimensions of biodiversity: New perspectives and methods

Although the knowledge and understanding of biodiversity is rapidly increasing, very little of the total biodiversity is currently considered in applied conservation actions. In this sense, it is crucial to integrate independent fields of biodiversity models and perspectives with conservation issues, in particular, the views that address the links between biodiversity, ecosystem services and human well-being, species interaction, and focal charismatic species. This study overcomes the lack of framework necessary for this integration, and proposes three perspectives and approaches to assess biodiversity. The first perspective is biodiversity potential. It considers the correlation between renewable resources in local ecosystems and biodiversity potential, in terms of the possibility of maintaining a high degree of biodiversity. The energy cost is evaluated using both static and dynamic methods, based on the measure of the emergy of local renewable resources and of the total emergy throughput needed by components in ecosystem food webs, respectively, also highlighting the link between biodiversity and ecosystem services, species interactions via energy transfer respectively. The second perspective considers the contribution of biodiversity to human well-being, such as domestication. In this approach, we assess the contribution of biodiversity to humans by calculating the emergy of non-renewable resources required to domesticate animals or plants into agricultural products. The third perspective highlights the significance of local focal charismatic species to global biodiversity conservation. Taking rare species as an example, the emergy required to maintain rare species per unit area is used as a quantitative indicator of the role of local rare species in maintaining global biodiversity. By measuring biodiversity from these three perspectives (potential, contribution and significance) simultaneously, biodiversity conservation strategies are addressed for different regions. Taking China as a case study, it shows that the provinces featuring high potential, low contribution and low significance can moderately increase biodiversity development. The provinces with high significance to global biodiversity should strengthen conservation to halt biodiversity loss. The areas exhibiting overexploitation of biodiversity should in turn restrict biodiversity exploitation. The general approaches proposed in this study could be applied to different cases, situations and species, promoting the integration to biodiversity conservation actions at different scales.

Evaluating the conservation value of sacred forests for ant taxonomic, functional and phylogenetic diversity in highly degraded landscapes

Land use changes and accelerating deforestation rates impact biodiversity on a global scale. While it is well established that the loss of primary forests is devastating, considerably less is understood about the conservation value of sacred forests (e.g. Feng shui woods in China) as local biodiversity reservoirs in human influenced landscapes. When these forests were assessed, the focus was generally on floral diversity, while faunal aspects were neglected. Here we address this knowledge gap by evaluating several dimensions of faunal biodiversity in Hong Kong Feng shui woods. We compare taxonomic, phylogenetic and functional elements of the leaf litter dwelling ant fauna collected over five years among Feng shui woods and two woody habitats corresponding to two distinct successional stages. Ant assemblages in Feng shui woods presented higher species richness that were more resilient to invasions by tramp species, and encompassed specialist species with a distinct set of traits. Phylogenetic diversity was similar in Feng shui and successional woods, while functional diversity was clustered in early successional habitats. The scarcity of tramp species and presence of specialists in Feng shui woods despite their close proximity to human settlements highlights their conservation value for native species in highly degraded landscapes. Our results provide much needed insight on the faunal biodiversity of Feng shui woods. We highlight the conservation value and urgent need for a better protection of these widely overlooked sacred forests in highly disturbed landscapes.

A new composite abundance metric detects stream fish declines and community homogenization during six decades of invasions

AbstractAimWe developed a new technique, utilizing species‐specific counts of individuals from historical fish community samples, to examine landscape‐level, spatio‐temporal trends in relative abundance distributions. Abundance‐based historical distribution analyses are often plagued by data comparability issues, but provide critical information about community composition trends inaccessible to those using analyses based only on species presence–absence. We established trends in native and non‐native fish abundance and community homogenization, uniqueness and diversity to help local conservation managers prioritize targets and motivate similar studies globally to support fish conservation.LocationUpper and middle New River (UMNR) basin, Appalachian Mountains, USA.MethodsWe compiled catch data from 61 years of fish community surveys (1958–2019) and tested for community homogenization by comparing data from repeatedly sampled sites (1900s versus 2000s samples) using dispersion analyses. We measured community uniqueness (site contributions to beta diversity) and species diversity (Shannon index) at sampled streams to identify potential conservation hotspots. We then used regression analyses and Wilcoxon signed‐rank tests to examine species‐specific basin‐wide and local abundance trends and identify species of potential conservation concern.ResultsDispersion of sites in species abundance space was significantly greater in the 1900s compared with the 2000s, indicating homogenization had occurred. Of 36 native species analysed, 44.4% (16) showed basin‐wide declines. Non‐native species exhibited mixed patterns; site‐level abundance increased in 2 of 15 species analysed (13%).Main conclusionsOur results indicate basin‐wide community homogenization has occurred within the UMNR, but many unique and diverse communities persist. If conserved, these could help maintain regional fish diversity. We found basin‐wide declines in four endemic species, as well as spread patterns of non‐native and native species that were not detected by a presence–absence analysis applied within the same study area. This finding illustrates the importance of considering both species’ abundance and occurrence patterns as separate dimensions of biodiversity to inform conservation planning.

The hidden side of diversity: Effects of imperfect detection on multiple dimensions of biodiversity.

Studies on ecological communities often address patterns of species distribution and abundance, but few consider uncertainty in counts of both species and individuals when computing diversity measures.We evaluated the extent to which imperfect detection may influence patterns of taxonomic, functional, and phylogenetic diversity in ecological communities.We estimated the true abundance of fruit‐feeding butterflies sampled in canopy and understory strata in a subtropical forest. We compared the diversity values calculated by observed and estimated abundance data through the hidden diversity framework. This framework evaluates the deviation of observed diversity when compared with diversities derived from estimated true abundances and whether such deviation represents a bias or a noise in the observed diversity pattern.The hidden diversity values differed between strata for all diversity measures, except for functional richness. The taxonomic measure was the only one where we observed an inversion of the most diverse stratum when imperfect detection was included. Regarding phylogenetic and functional measures, the strata showed distinct responses to imperfect detection, despite the tendency to overestimate observed diversity. While the understory showed noise for the phylogenetic measure, since the observed pattern was maintained, the canopy had biased diversity for the functional metric. This bias occurred since no significant differences were found between strata for observed diversity, but rather for estimated diversity, with the canopy being more clustered.We demonstrate that ignore imperfect detection may lead to unrealistic estimates of diversity and hence to erroneous interpretations of patterns and processes that structure biological communities. For fruit‐feeding butterflies, according to their phylogenetic position or functional traits, the undetected individuals triggered different responses in the relationship of the diversity measures to the environmental factor. This highlights the importance to evaluate and include the uncertainty in species detectability before calculating biodiversity measures to describe communities.

Exploring shared public perspectives on biodiversity attributes

Abstract Researchers, practitioners and policymakers have widely documented the multifarious ways that nature influences human well‐being. However, we still have only a limited understanding of how the public interact with, respond to and talk about attributes of biodiversity. We used image‐based Q methodology to explore the shared and contrasting perspectives people hold for biodiversity. This approach is a powerful way of allowing people to articulate what is, or is not, important to them, free from constraints associated with statement‐based stimuli. We used British woodlands as a study system, as they are accessible and well‐visited by the public. The elements of biodiversity incorporated in the Q methodology represented vertebrates, invertebrates, trees and understorey plants and fungi. The shared public perspectives varied, and the reasons underpinning those perspectives were rich and diverse. People articulated reasons related to an array of biodiversity attributes (e.g. functions, behaviours, colours, smells, shapes). Many of the perspectives transcended specific species or taxonomic groups. Although woodlands were used as a study system, people referenced perceptions and experiences external to this habitat (e.g. within their gardens) and associated with their everyday lives. Cultural influences and memories linked to particular people and places were also prominent. Few of the shared perspectives map onto the objective measures and dimensions that researchers use to describe and categorise biodiversity (e.g. rarity, ecosystem service provision). A free Plain Language Summary can be found within the Supporting Information of this article.

A global database of plant services for humankind.

Humanity faces the challenge of conserving the attributes of biodiversity that may be essential to secure human wellbeing. Among all the organisms that are beneficial to humans, plants stand out as the most important providers of natural resources. Therefore, identifying plant uses is critical to preserve the beneficial potential of biodiversity and to promote basic and applied research on the relationship between plants and humans. However, much of this information is often uncritical, contradictory, of dubious value or simply not readily accessible to the great majority of scientists and policy makers. Here, we compiled a genus-level dataset of plant-use records for all accepted vascular plant taxa (13489 genera) using the information gathered in the 4th Edition of Mabberley's plant-book, the most comprehensive global review of plant classification and their uses published to date. From 1974 to 2017 all the information was systematically gathered, evaluated, and synthesized by David Mabberley, who reviewed over 1000 botanical sources including modern Floras, monographs, periodicals, handbooks, and authoritative websites. Plant uses were arranged across 28 standard categories of use following the Economic Botany Data Collection Standard guidelines, which resulted in a binary classification of 9478 plant-use records pertaining human and animal nutrition, materials, fuels, medicine, poisons, social and environmental uses. Of all the taxa included in the dataset, 33% were assigned to at least one category of use, the most common being "ornamental" (26%), "medicine" (16%), "human food" (13%) and "timber" (8%). In addition to a readily available binary matrix for quantitative analyses, we provide a control text matrix that links the former to the description of the uses in Mabberley's plant-book. We hope this dataset will serve to establish synergies between scientists and policy makers interested in plant-human interactions and to move towards the complete compilation and classification of the nature's contributions to people upon which the wellbeing of future generations may depend.

Simulating Imaging Spectroscopy in Tropical Forest with 3D Radiative Transfer Modeling

Optical remote sensing can contribute to biodiversity monitoring and species composition mapping in tropical forests. Inferring ecological information from canopy reflectance is complex and data availability suitable to such a task is limiting, which makes simulation tools particularly important in this context. We explored the capability of the 3D radiative transfer model DART (Discrete Anisotropic Radiative Transfer) to simulate top of canopy reflectance acquired with airborne imaging spectroscopy in a complex tropical forest, and to reproduce spectral dissimilarity within and among species, as well as species discrimination based on spectral information. We focused on two factors contributing to these canopy reflectance properties: the horizontal variability in leaf optical properties (LOP) and the fraction of non-photosynthetic vegetation (NPVf). The variability in LOP was induced by changes in leaf pigment content, and defined for each pixel based on a hybrid approach combining radiative transfer modeling and spectral indices. The influence of LOP variability on simulated reflectance was tested by considering variability at species, individual tree crown and pixel level. We incorporated NPVf into simulations following two approaches, either considering NPVf as a part of wood area density in each voxel or using leaf brown pigments. We validated the different scenarios by comparing simulated scenes with experimental airborne imaging spectroscopy using statistical metrics, spectral dissimilarity (within crowns, within species, and among species dissimilarity) and supervised classification for species discrimination. The simulation of NPVf based on leaf brown pigments resulted in the closest match between measured and simulated canopy reflectance. The definition of LOP at pixel level resulted in conservation of the spectral dissimilarity and expected performances for species discrimination. Therefore, we recommend future research on forest biodiversity using physical modeling of remote-sensing data to account for LOP variability within crowns and species. Our simulation framework could contribute to better understanding of performances of species discrimination and the relationship between spectral variations and taxonomic and functional dimensions of biodiversity. This work contributes to the improved integration of physical modeling tools for applications, focusing on remotely sensed monitoring of biodiversity in complex ecosystems, for current sensors, and for the preparation of future multispectral and hyperspectral satellite missions.

Latitudinal variation in long-term stability of North American rocky intertidal communities.

Although long‐term ecological stability is often discussed as a community attribute, it is typically investigated at the species level (e.g. density, biomass), or as a univariate metric (e.g. species diversity). To provide a more comprehensive assessment of long‐term community stability, we used a multivariate similarity approach that included all species and their relative abundances.We used data from 74 sites sampled annually from 2006 to 2017 to examine broad temporal and spatial patterns of change within rocky intertidal communities along the west coast of North America. We explored relationships between community change (inverse of stability) and the following potential drivers of change/stability: (a) marine heatwave events; (b) three attributes of biodiversity: richness, diversity and evenness and (c) presence of the mussel, Mytilus californianus, a dominant space holder and foundation species in this system.At a broad scale, we found an inverse relationship between community stability and elevated water temperatures. In addition, we found substantial differences in stability among regions, with lower stability in the south, which may provide a glimpse into the patterns expected with a changing climate. At the site level, community stability was linked to high species richness and, perhaps counterintuitively, to low evenness, which could be a consequence of the dominance of mussels in this system. Synthesis. Assessments of long‐term stability at the whole‐community level are rarely done but are key to a comprehensive understanding of the impacts of climate change. In communities structured around a spatially dominant species, long‐term stability can be linked to the stability of this ‘foundation species’, as well as to traditional predictors, such as species richness.

The potential of secondary forests to restore biodiversity of the lost forests in semi-deciduous West Africa

In West Africa, more than 80% of the original forest cover has disappeared due to the exponential growth of human populations in a recurrent search for new agricultural land. Once the fertility of the land is exhausted, these areas are abandoned and left to be reforested through natural succession. Despite the widespread presence of secondary forests of various ages in West African landscapes, little is known about the trajectories of recovery and the environmental factors that influence recovery rates. We set up 96 0.2 ha forest plots, along a chronosequence of 1 to 40 years and including 7 controls, on which all trees larger than 2.5 cm in diameter at breast height were inventoried. We modelled the recovery trajectories of four complementary dimensions of biodiversity (richness, diversity, composition, indicators of old-growth forest) in a Bayesian framework. Our results show that the four dimensions of biodiversity recover at different rates, with composition recovering much faster than floristic diversity. Among the local, landscape, and historical factors studied, the number of remnants and proximity to old-growth forests have a positive impact on recovery rates, with, under good environmental conditions, the composition, richness, and diversity being almost completely recovered in less than 25 years. Our results demonstrate the very high resilience of the composition of the semi-deciduous forests of West Africa, but also suggest that the management of these post-forest areas must be differentiated according to the landscape context and the presence of isolated trees, which are the last vestiges of the former forest. In unfavourable conditions, natural dynamics should be assisted by agroforestry practices and local tree planting to allow for a rapid restoration of forest goods and services to local populations.

Conservation risks and portfolio effects in mixed‐stock fisheries

AbstractFish biodiversity sustains the resilience and productivity of fisheries, yet this biodiversity can be threatened by overharvest and depletion in mixed‐stock fisheries. Thus, the biodiversity that provides benefits may also make sustainable resource extraction more difficult, a key challenge in fisheries management. We simulated a mixed‐stock fishery to explore relationships between different dimensions of biodiversity and fishery performance relative to conservation and fishery objectives. Different dimensions of biodiversity (number of stocks, evenness, asynchrony among stocks, heterogeneity in stock productivity) exacerbated trade‐offs between fishery and conservation objectives. For example, fisheries targeting stock‐complexes with greater asynchrony, and to a lesser extent richness, had greater stability in harvest through time but also greater risks of overfishing weak stocks and reduced yield compared to less biodiverse stock‐complexes. These trade‐offs were ameliorated by increasing management control—the capacity of fishery managers to harvest specific stocks. To explore these trade‐offs in real‐world fisheries, we contrasted the fishing and population status of individual stocks within three major mixed‐stock sockeye salmon (Oncorhynchus nerka, Salmonidae) fisheries—Bristol Bay, Fraser River, and Skeena River. In general, the fisheries with lower management control had individual stocks that were more often being over‐ or under‐fished, compared with those with higher management control, though variation among regions in biodiversity, scale of management, and magnitude of habitat alteration likely also contribute to these relationships. Collectively, our findings emphasize that there is a need to extract less or regulate better in order to conserve and benefit from biodiversity in fisheries and other natural resource management systems.

Plant spectral diversity as a surrogate for species, functional and phylogenetic diversity across a hyper‐diverse biogeographic region

AbstractAimWith plant biodiversity under global threat, there is an urgent need to monitor the spatial distribution of multiple axes of biodiversity. Remote sensing is a critical tool in this endeavour. One remote sensing approach for detecting biodiversity is based on the hypothesis that the spectral diversity of plant communities is a surrogate of multiple dimensions of biodiversity. We investigated the generality of this ‘surrogacy’ for spectral, species, functional and phylogenetic diversity across 1,267 plots in the Greater Cape Floristic Region (GCFR), a hyper‐diverse region comprising several biomes and two adjacent global biodiversity hotspots.LocationThe GCFR centred in south‐western and western South Africa.Time periodAll data were collected between 1978–2014.Major taxa studiedVascular plants within the GCFR.MethodsSpectral diversity was calculated using leaf reflectance spectra (450–950 nm) and was related to other dimensions of biodiversity via linear models. The accuracy of different spectral diversity metrics was compared using 10‐fold cross‐validation.ResultsWe found that a distance‐based spectral diversity metric was a robust predictor of species, functional and phylogenetic biodiversity. This result serves as a proof‐of‐concept that spectral diversity is a potential surrogate of biodiversity across a hyper‐diverse biogeographic region. While our results support the generality of spectral diversity as a biodiversity surrogate, we also find that relationships vary between different geographic subregions and biomes, suggesting that differences in broad‐scale community composition can affect these relationships.Main conclusionsSpectral diversity was shown to be a robust surrogate of multiple dimensions of biodiversity across biomes and a widely varying biogeographic region. We also extend these surrogacy relationships to ecological redundancy to demonstrate the potential for additional insights into community structure based on spectral reflectance.