Shared posts
Forest fragmentation leading to higher extinction rates
Biogeography of exotic ants
Human transportation facilitates the dispersal of exotic ants, but few studies have quantified the magnitude and geography of these movements. We used several non-parametric indexes to estimate the number of species successfully introduced to or established in new regions. We also compared their source biogeographic realms to assess the importance of the geographical origin in determining the likelihood of establishment after introduction. Data on exotic ants derive from studies of three temperate regions. Our results suggest that the numbers of introduced or established ants may be much larger than the numbers so far documented. Ants introduced or established in new regions tend to arrive from the same or neighbouring realms, as would be expected if exotic species tend to match climates and if arrival/establishment is dependent upon higher trade rates from neighbouring countries.
Not only habitat but also sex. Factors conditioning spatial distribution of little bustard Tetrax tetrax families
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Gerard Bota, membre de BAC-Lab, ha participat en un nou article liderat per Rocío Tarjuelo (UAM, Madrid) i publicat a Acta Ornithologica. En aquest estudi es va analitzar la distribució espacial de les famílies de sisó (femelles amb polls) durant la temporada de reproducció en relació amb la distribució de les àrees de concentració de mascles en tres poblacions espanyoles de l’espècie. |
Els patrons de distribució de les espècies estan determinats no només per les preferències d’hàbitat, sinó també per factors biòtics. En particular, la presència de congèneres pot aportar diferents tipus de beneficis i costos per als individus. Això també és rellevant en el context de l’avaluació de diferents escenaris agronòmics i el seu possible impacte sobre les poblacions de sisó.
El patró de selecció de l’hàbitat va ser similar entre les regions, amb els guarets i rostolls com els usos més seleccionats. Per contra, altres usos com ara els llaurats, van ser rebutjats. La distribució de femelles amb polls de sisó estaven més properes a les zones de concentració de mascles del que caldria esperar per l’atzar i van estar clarament associades als llocs de cant dels mascles. Les femelles de sisó poden obtenir diferents beneficis d’aquesta associació espacial, com ara l’accés a més recursos alimentaris i millorar les oportunitats de segons aparellaments després d’una pèrdua de posta. Aquests resultats posen de manifest la importància de les interaccions intraespecífiques en la definició del model de selecció d’hàbitat de les femelles de sisó amb polls. Aquest estudi també mostra com l’anàlisi de patrons espacials pot ser una eina útil per a la integració de la ecologia del paisatge i el comportament.
Aquest treball és una contribució al projecte Steppeahead finançat per la Fundació General CSIC-Banco Santander.
Per més infromació:
Mapping habitat suitability for at-risk plant species and its implications for restoration and reintroduction
The conservation of species at risk of extinction requires data to support decisions at landscape to regional scales. There is a need for information that can assist with locating suitable habitats in fragmented and degraded landscapes to aid the reintroduction of at-risk plant species. In addition, desiccation and water stress can be significant barriers to the success of at-risk plant reintroduction programs. We examine how airborne light detection and ranging (LiDAR) data can be used to model microtopographic features that reduce water stress and increase resource availability, providing information for landscape planning that can increase the success of reintroduction efforts for a dryland landscape in Hawaii. We developed a topographic habitat-suitability model (HSM) from LiDAR data that identifies topographic depressions that are protected from prevailing winds (high-suitability sites) and contrasts them with ridges and other exposed areas (low-suitability sites). We tested in the field whether high-suitability sites had microclimatic conditions that indicated better-quality habitat compared to low-suitability sites, whether plant-response traits indicated better growing conditions in high-suitability sites, whether the locations of individuals of existing at-risk plant species corresponded with our habitat-suitability classes, and whether the survival of planted individuals of a common native species was greater in high-suitability, compared to low-suitability, planting sites. Mean wind speed in a high-suitability field site was over five times lower than in a low-suitability site, and soil moisture and leaf wetness were greater, indicating less stress and greater resource availability in high-suitability areas. Plant height and leaf nutrient content were greater in high-suitability areas. Six at-risk species showed associations with high-suitability areas. The survival of planted individuals was less variable among high-suitability plots. These results suggest that plant establishment and survival is associated with the habitat conditions identified by our model. The HSM can improve the survival of planted individuals, reduce the cost of restoration and reintroduction programs through targeted management activities in high-suitability areas, and expand the ability of managers to make landscape-scale decisions regarding land-use, land acquisition, and species recovery.
Pre-wildfire fuel reduction treatments result in more resilient forest structure a decade after wildfire
Pre-wildfire thinning and fuel reduction treatments increased tree survival compared with untreated sites following the 2002 Rodeo–Chediski Fire. A decade later, treated sites have stand basal areas that fall within target ranges for increasing resiliency to future fires. Surface fuels were within acceptable levels and are unlikely to increase substantially.
Integrated assessment models for ecologists: the present and the future
Abstract
Aim
Human impacts on the biosphere are a matter of urgent and growing concern, with ecologists increasingly being asked to project biodiversity futures. The Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) is likely to comprehensively assess such projections, yet despite being widely used and potentially critical tools for analysing socio-environmental futures, integrated assessment models (IAMs) have received little attention from ecological modellers. We aim to raise awareness and understanding of IAMs among ecologists by describing the structure and composition of IAMs, assessing their utility for biodiversity projections and identifying limitations that hamper greater interaction between scientists using IAMs and those using ecological models. We also hope to inspire more accessible and applicable models by suggesting development needs for IAMs.
Methods
We conduct a systematic review of four state-of-the-art IAMs, which describes and contrasts key model features and analyses six aspects of IAMs that are of fundamental interest to ecologists.
Conclusions
IAMs could be valuable for modelling biodiversity futures; however, current IAMs were not developed for this application and challenges remain for ecologists looking to use their outputs. Separating and understanding the differences resulting from IAM formulation and those resulting from specific scenario assumptions is currently problematic, and current IAMs may be unable to accurately represent environmental conditions for both Earth-system projections and for building robust models of biodiversity because key ecological processes are absent. We suggest that model intercomparisons would identify differences in model dynamics, and detailed studies of how dynamical interactions between components influence behaviour would address why such differences arise. Bio-economic fisheries models and agriculture pollination models provide starting points for integrating key ecological feedbacks within IAMs. Ultimately, making IAMs more accessible within the multidisciplinary study of global change, drawing on user-centred research, would enable more resolved, reliable and accurate assessment of how Earth's socio-ecological system is approaching planetary boundaries.
Stacking species distribution models and adjusting bias by linking them to macroecological models
Abstract
Aim
Species distribution models (SDMs) are common tools in biogeography and conservation ecology. It has been repeatedly claimed that aggregated (stacked) SDMs (S-SDMs) will overestimate species richness. One recently suggested solution to this problem is to use macroecological models of species richness to constrain S-SDMs. Here, we examine current practice in the development of S-SDMs to identify methodological problems, provide tools to overcome these issues, and quantify the performance of correctly stacked S-SDMs alongside macroecological models.
Locations
Barents Sea, Europe and Dutch Wadden Sea.
Methods
We present formal mathematical arguments demonstrating how S-SDMs should and should not be stacked. We then compare the performance of macroecological models and correctly stacked S-SDMs on the same data to determine if the former can be used to constrain the latter. Next, we develop a maximum-likelihood approach to adjusting S-SDMs and discuss how it could potentially be used in combination with macroecological models. Finally, we use this tool to quantify how S-SDMs deviate from observed richness in four very different case studies.
Results
We demonstrate that stacking methods based on thresholding site-level occurrence probabilities will almost always be biased, and that these biases will tend toward systematic overprediction of richness. Next, we show that correctly stacked S-SDMs perform very similarly to macroecological models in that they both have a tendency to overpredict richness in species-poor sites and underpredict it in species-rich sites.
Main conclusions
Our results suggest that the perception that S-SDMs consistently overpredict richness is driven largely by incorrect stacking methods. With these biases removed, S-SDMs perform similarly to macroecological models, suggesting that combining the two model classes will not offer much improvement. However, if situations where coupling S-SDMs and macroecological models would be beneficial are subsequently identified, the tools we develop would facilitate such a synthesis.
Extinction debt and the species–area relationship: a neutral perspective
Abstract
Aim
To estimate the magnitude of delayed relative to imminent extinctions and to assess the importance of delay as a potential source of error in forecasts of extinction. To formulate a simple mechanistic model using neutral theory that links extinction debt with the species–area relationship (SAR).
Location
World-wide.
Methods
We use the neutral model of biodiversity to describe how a community subject to immigration responds to an insular contraction. We investigate the species richness at different times after the habitat-loss event. We compare this with observed species losses in avian studies.
Results
From the model, two SARs emerge: one with a shallow slope for a habitat area before habitat loss and another with a steeper slope for the habitats that remain after habitat loss. From these curves, the first predicts imminent extinctions while the second predicts total extinctions. The difference between the two curves gives the delayed extinctions, namely the number of species that are lost during the relaxation of the community to equilibrium. The model agrees well with observed relaxation rates in communities of birds. The lag times for relaxation are often very large, with half-lives in the order of thousands of years for remnant areas above 5000 km2. In many parameter combinations explored, the majority of extinctions are delayed extinctions, and may exceed imminent extinctions by orders of magnitude.
Main conclusions
Extinction debt is a major reason for failures to observe extinctions following habitat loss. Our modelling approach supports the view that a significant proportion of extinctions are delayed, so that the predictions of SARs (as currently applied) are liable to underestimate total extinctions. SARs are a valuable instrument for conservation but must be used with caution.
Using landscape history to predict biodiversity patterns in fragmented landscapes
Abstract
Landscape ecology plays a vital role in understanding the impacts of land-use change on biodiversity, but it is not a predictive discipline, lacking theoretical models that quantitatively predict biodiversity patterns from first principles. Here, we draw heavily on ideas from phylogenetics to fill this gap, basing our approach on the insight that habitat fragments have a shared history. We develop a landscape ‘terrageny’, which represents the historical spatial separation of habitat fragments in the same way that a phylogeny represents evolutionary divergence among species. Combining a random sampling model with a terrageny generates numerical predictions about the expected proportion of species shared between any two fragments, the locations of locally endemic species, and the number of species that have been driven locally extinct. The model predicts that community similarity declines with terragenetic distance, and that local endemics are more likely to be found in terragenetically distinctive fragments than in large fragments. We derive equations to quantify the variance around predictions, and show that ignoring the spatial structure of fragmented landscapes leads to over-estimates of local extinction rates at the landscape scale. We argue that ignoring the shared history of habitat fragments limits our ability to understand biodiversity changes in human-modified landscapes.
Research into action: grey partridge conservation as a case study
Will pre-adaptation buffer the impacts of climate change on novel species interactions?
Species are expected to alter their ranges as climates change. Climate-induced range expansions of predators could threaten evolutionarily naïve prey populations, leading to high mortality at the invasion front. If prey can apply existing defenses against local predators to novel predation threats induced by climate change, mortality threats will be less than expected. Here, we examine if spotted salamander larvae Ambystoma maculatum from populations that coexist with native red-spotted newts Notophthalmus viridescens survive better when exposed to a novel predator, the marbled salamander Ambystoma opacum. We show that regional mean winter temperatures warmed 2.0°C over 116 yr in the region, and that A. opacum survival increases in ponds with higher winter temperatures. Hence as winters continue to warm, this apex predator will likely colonize ponds north of their current range limit. Next, we performed common garden experiments to determine if local adaptations to native N. viridescens and exposure to A. opacum or N. viridescens kairomones (predator chemical cues) altered A. maculatum survival in predation trials. We did not find evidence for local adaptation to N. viridescens. However, A. maculatum from high-N. viridescens ponds that were reared with A. opacum kairomones suffered significantly higher mortality from the native predator N. viridescens. This outcome suggests an unanticipated interaction between local adaptation and plastic responses to novel kairomones from a potentially range-expanding predator. Current projections of biodiversity losses from climate change generally ignore the potential for eco-evolutionary interactions between native and range-expanding species and thus could be inaccurate.
Phylogenetic generalised dissimilarity modelling: a new approach to analysing and predicting spatial turnover in the phylogenetic composition of communities
Compared to species turnover, patterns of phylogenetic turnover provide extra information about the spatial structure of biodiversity, for example providing more informative comparisons between the biota of sites which share no species. To harness this information for broad-scale spatial analysis, we present phylo-GDM, a technique for interpolating the spatial structure of phylogenetic turnover between sampled locations in relation to environment, based on generalised dissimilarity modelling (GDM).
Using a database of over 150 000 location records for 114 myobatrachid frog species in Australia, linked to a species-level phylogeny inferred from 2467 base pairs of mitochondrial DNA, we calculated species and phylogenetic turnover between pairs of sites. We show how phylogenetic turnover extended the range of informative comparison of compositional turnover to more biologically and environmentally dissimilar sites. We generated GDM models which predict species and phylogenetic turnover across Australia, and tested the fit of models for different ages within the phylogeny to find the phylogenetic tree depth at which the relationship to current day environment is greatest. We also incorporated explanatory variables based on biogeographic patterns, to represent broad-scale turnover resulting from divergent evolutionary histories. We found that while the predictive power of our models was lower for full phylogenetic turnover than for species turnover, models based on the more recent components of the phylogeny (closer to the tips) outperformed species models and full phylogenetic models.
Phylo-GDM has considerable potential as a method for incorporating phylogenetic relationships into biodiversity analyses in ways not previously possible. Because phylogenies do not require named taxa, phylo-GDM may also provide a means of including lineages with poorly resolved taxonomy (e.g. from metagenomic sequencing) into biodiversity planning and phylogeographic analysis.
Uncertainty in distribution forecasts caused by taxonomic ambiguity under climate change scenarios: a case study with two newt species in mainland Spain
Abstract
Aim
To analyse a source of uncertainty when forecasting the possible effects of climate change on species distributions, which may appear when the species studied have doubtful taxonomy or are subdivided into subspecies with different environmental requirements.
Location
Mainland Spain.
Methods
Iberian newts (Triturus pygmaeus and Triturus marmoratus, a recently identified species) were used as examples. Environmental favourability models were performed on the occurrence of the newts according to two taxonomic options: (1) the two species separately; and (2) the two species together, as they were considered a single species by taxonomists until recently. The models were projected to three time periods between 2011 and 2100 within a context of climate change, using two different general circulation models and two emission scenarios. We calculated the discrepancy between forecasts produced with the different taxonomic options and their consistency under the same climate change scenario.
Results
The model based on the two species together did not distinguish between particular environmental requirements of either of the two species. Discrepancy values between taxonomic options increased over time. A reduction in areas favourable to T. pygmaeus and its north-eastward displacement were only predicted when this species was analysed separately. Nevertheless, the uncertainty derived from taxonomic ambiguity barely affected the predictions for T. marmoratus.
Main conclusions
Qualitatively and quantitatively different distribution forecasts for two newt species in mainland Spain were obtained depending on the taxonomic option considered. Taxonomic uncertainty also affected other sources of uncertainty. Some guidelines are suggested to aid in similar cases.
FarmLand: Finalitza el treball de camp del 2013
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Recentment, ha finalitzat el treball de camp del 2013 del projecte FARMLAND. Finalment s’han pogut mostrejar 25 paisatges diferents d’1×1 km en diferents zones de secà de la Plana de Lleida, mostrejant un total de 75 camps de cultius diferents. Aquests camps s’han pogut mostrejar gràcies a la col·laboració de fins a 65 propietaris diferents que han facilitat l’accés a les seves finques. |
S’ha obtingut una gran quantitat d’informació de grups biòtics tan diferents com ara ocells, plantes ruderals o insectes com ara sírfids, aranyes, papallones i caràbids que ara caldrà començar analitzar conjuntament amb les dades d’altres zones d’Europa. També s’han pogut realitzat diferents experiments sobre serveis ecosistèmics en relació a la pol·linització i depredació. A més a més, la primera setmana d’agost també s’han realitzat les enquestes als propietaris per tal d’obtenir informació detallada de la gestió que realitzen de les seves finques (podes, dates i tipologies de tractaments aplicats, plagues detectades, data de recol·lecció…).
| El projecte FARMLAND és un projecte d’investigació que reuneix grups de França, Alemanya, Gran Bretanya, Espanya i Canadà per tal d’examinar el rol de l’heterogeneïtat del paisatge agrícola en la biodiversitat i els serveis ecosistèmics en els sistemes agrícoles. |  |
Per més informació: pàgina oficial del projecte Farmland
Climatic history and beta-diversity
A common approach for analysing geographical variation in biodiversity involves using linear models to determine the rate at which species similarity declines with geographical or environmental distance and comparing this rate among regions, taxa or communities. Implicit in this approach are weakly justified assumptions that the rate of species turnover remains constant along gradients and that this rate can therefore serve as a means to compare ecological systems. We use generalized dissimilarity modelling, a novel method that accommodates variation in rates of species turnover along gradients and between different gradients, to compare environmental and spatial controls on the floras of two regions with contrasting evolutionary and climatic histories: southwest Australia and northern Europe. We find stronger signals of climate history in the northern European flora and demonstrate that variation in rates of species turnover is persistent across regions, taxa and different gradients. Such variation may represent an important but often overlooked component of biodiversity that complicates comparisons of distance–decay relationships and underscores the importance of using methods that accommodate the curvilinear relationships expected when modelling beta diversity. Determining how rates of species turnover vary along and between gradients is relevant to understanding the sensitivity of ecological systems to environmental change.
Land-use impacts on plant–pollinator networks: interaction strength and specialization predict pollinator declines
Land use is known to reduce the diversity of species and complexity of biotic interactions. In theory, interaction networks can be used to predict the sensitivity of species against co-extinction, but this has rarely been applied to real ecosystems facing variable land-use impacts. We investigated plant–pollinator networks on 119 grasslands that varied quantitatively in management regime, yielding 25 401 visits by 741 pollinator species on 166 plant species. Species-specific plant and pollinator responses to land use were significantly predicted by the weighted average land-use response of each species' partners. Moreover, more specialized pollinators were more vulnerable than generalists. Both predictions are based on the relative interaction strengths provided by the observed interaction network. Losses in flower and pollinator diversity were linked, and mutual dependence between plants and pollinators accelerates the observed parallel declines in response to land-use intensification. Our findings confirm that ecological networks help to predict natural community responses to disturbance and possible secondary extinctions.
IPBES-2 registration for first-time stakeholder organizations
The first session of the IPBES Plenary, held in January 2013 in Bonn, Germany agreed a procedure as outlined in the meeting report Section B paragraph 22 would be applied solely for the second session of the Plenary (IPBES/1/12). As part of the approval process, stakeholder organizations not represented at IPBES-1 are requested to send in supporting documents describing the mandate, scope and governing structure of the organization (e.g. copy of a statute) to registration@ipbes.net as soon as possible and no later than Monday, 19 August 2013 in addition to filling in the registration form.
Upon receiving the supporting documents, your request will be submitted to the Bureau for review which will communicate their recommendations to the members of the Platform at least eight weeks before the opening of IPBES-2. Should any concerns arise from the members of the Platform, your organization will be notified of it at least two weeks in advance. Your organization's participation cannot be admitted unless it is approved by the members of the Platform.
The academic welfare state: making peer-review count
Predicting Global Patterns in Mangrove Forest Biomass
Abstract
Understanding spatial variation in carbon storage in natural habitats is critical for climate change mitigation efforts such as REDD. Terrestrial forests are being mapped with increasing accuracy, but the distribution of ``blue carbon'' in marine ecosystems remains poorly understood. We reviewed the literature to obtain field data on carbon storage and fluxes in mangroves world-wide. Using this material we developed a climate-based model for potential mangrove above-ground biomass (AGB) with almost four times the explanatory power of the only previous published model. From this model, we present the first ever global map of potential mangrove AGB and estimate a total global mangrove AGB of 2.83 Pg, with an average of 184.8 t ha−1. Data on other carbon stocks and fluxes confirm the importance of mangroves in carbon accounting. The map highlights the high variability in mangrove AGB and indicates areas that should be prioritised for mangrove conservation and restoration.
Modelling distributions of fossil sampling rates over time, space and taxa: assessment and implications for macroevolutionary studies
Summary
- Observed patterns in the fossil record reflect not just macroevolutionary dynamics, but preservation patterns. Sampling rates themselves vary not simply over time or among major taxonomic groups, but within time intervals over geography and environment, and among species within clades. Large databases of presences of taxa in fossil-bearing collections allow us to quantify variation in per-collection sampling rates among species within a clade. We do this separately not just for different time/stratigraphic intervals, but also for different geographic or ecologic units within time/stratigraphic intervals. We then re-assess per-million-year sampling rates given the distributions of per-collection sampling rates
- We use simple distribution models (geometric and lognormal) to assess general models of per-locality sampling rate distributions given occurrences among appropriate fossiliferous localities. We break these down not simply by time period, but by general biogeographic units in order to accommodate variation over space as well as among species.
- We apply these methods to occurrence data for Meso-Cenozoic mammals drawn from the Paleobiology Database and the New and Old Worlds fossil mammal database. We find that all models of distributed rates do vastly better than the best uniform sampling rates and that the lognormal in particular does an excellent job of summarizing sampling rates. We also show that the lognormal distributions vary fairly substantially among biogeographic units of the same age.
- As an example of the utility of these rates, we assess the most likely divergence times for basal (Eocene–Oligocene) carnivoramorphan mammals from North America and Eurasia using both stratigraphic and morphological data. The results allow for unsampled taxa or unsampled portions of sampled lineages to be in either continent and also allow for the variation in sampling rates among species. We contrast five models using stratigraphic likelihoods in different ways to summarize how they might affect macroevolutionary inferences.
Threats to Canadian species at risk: An analysis of finalized recovery strategies
Source:Biological Conservation, Volume 166
Author(s): Jenny L. McCune , William L. Harrower , Stephanie Avery-Gomm , Jason M. Brogan , Anna-Mária Csergő , Lindsay N.K. Davidson , Alice Garani , Luke R. Halpin , Linda P.J. Lipsen , Christopher Lee , Jocelyn C. Nelson , Laura R. Prugh , Christopher M. Stinson , Charlotte K. Whitney , Jeannette Whitton
In order to reverse the decline of imperilled species, we need to know what is threatening their survival. Canada’s Species at Risk Act (SARA) is intended to provide for the protection and recovery of species listed under the Act. Threats to SARA-listed species must be documented in recovery strategies, which also define recovery goals and critical habitat. We reviewed finalized recovery strategies for 146 species to determine the major threats to these species and whether designation of critical habitat or the relative ambition of recovery goals is associated with the nature of threats. We then compared our findings to the threats described in reports prepared by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), the independent body which prepares status reports for all imperilled species (including those not listed under SARA). Human disturbance, in particular due to recreation, was the most frequently listed threat in recovery strategies, followed by invasive species and residential and commercial development. Threats differed among taxonomic groups and broad habitat types, but there was no evidence that low ambition of recovery goals or failure to designate critical habitat were correlated with particular threats. However, species with certain threats, including biological resource use, were less likely either to be listed under SARA and/or to have a finalized recovery strategy once listed. Documenting threat-based differences in the recovery process is an important first step toward ensuring that SARA results in timely and effective measures to recover all listed species.
Effects of forest disturbance and habitat loss on avian communities in a Neotropical biodiversity hotspot
Source:Biological Conservation, Volume 166
Author(s): Renata Durães , Luis Carrasco , Thomas B. Smith , Jordan Karubian
Regenerating forests are increasingly ubiquitous in tropical landscapes. They hold great conservation potential and there is demand for assessments of their biodiversity value. Forest disturbance and forest loss often occur together, yet few studies attempt to disentangle their separate effects on biological communities. In the Ecuadorian Chocó, a biodiversity hotspot, we sampled understory birds in patches with increasing levels of disturbance (old-growth, selectively-logged, and secondary forests) within contiguous forest and in fragments. Species richness increased with disturbance but decreased with habitat loss, with a 75% reduction in endemic and threatened species in fragments compared to contiguous forest. This reduction in richness was most pronounced in secondary forest fragments, suggesting that disturbance and habitat loss interact synergistically to maximally reduce avian biodiversity. Species composition was strongly affected by habitat loss and, to a lesser extent, disturbance, with forest fragments and secondary forests presenting distinct communities dominated by generalists with medium-to-low sensitivity to anthropogenic disturbance and reduced proportions of endemics and endangered species. Capture rates also decreased (non-significantly) with habitat loss, and the relative abundance of dietary guilds varied in response to both habitat loss and disturbance. Our study shows that regenerating patches surrounded by contiguous forest can sustain high biodiversity levels and, when past habitat disturbance is mild, present similar communities to old-growth forests. In contrast, forest loss caused reductions in richness (especially in more disturbed patches), profound changes in community composition, and loss of species of conservation concern. These results underscore the importance of considering landscape context when evaluating the conservation value of disturbed forests.
Defining the burden of proof in conservation
Source:Biological Conservation, Volume 166
Author(s): Nick Salafsky , Kent H. Redford
Conservationists often must take action in the face of uncertainty about the costs and benefits of different options. Although this uncertainty can be paralyzing when the stakes are high, there is obviously a cost to inaction as well as action, and decision makers need to be encouraged to act when appropriate. Many other fields of human endeavor such as law, medicine, and public safety have formally developed the “burden and standards of proof” that decision makers have to meet in choosing to take action. In this paper, we review the standards developed in these other fields to help define a similar framework for conservation. Specifically we propose that a conservation decision maker must assume the burden of proof when there is a decision to act that substantially affects others, in which the decision maker has professional standing, where there is not immediate urgency, and where there is some, but not complete certainty about the outcomes of acting versus not acting. Once these initial tests have been met, in situations in which the decision maker is more worried about the consequences of not acting, then a relatively low standard of proof is required for taking action. If the decision maker is concerned with the consequences of acting in error, but the action is relatively reversible, then a medium standard of proof is required. And finally, if there are concerns about the consequences of acting in error, but the action is relatively irreversible, then a high standard of proof is required.
Fathom out: biogeographical subdivision across the Western Australian continental margin – a multispecies modelling approach
Abstract
Aim
Biogeographical regions are often used as a basis for management strategies, yet a challenge for biodiversity management across broad scales is establishing biogeographical regions that are robust across taxonomic groups.
Methods
Finite mixture models were developed to predict multiple species assemblages termed archetypes. Modelled species archetypes were developed using Decapoda, Ophiuroidea and Polychaeta species, which were grouped based on their similar responses to oceanographic and geographical gradients.
Location
Outer-shelf and slope (50–1200 m) of the continental margin of Western Australia (~11° S–36° S).
Results
Four faunal regions were defined based on cross-taxa surrogates grouped as archetypes. These faunal regions were defined by oxygen, salinity, carbon and temperature gradients across latitude and bathymetry. Two broad latitudinal bands and two bathyal regions were described. Adjacent faunal groups were not defined by abrupt geographical breaks but rather transitions.
Main conclusions
These results suggest that faunal distributions were less finely resolved than existing marine bioregions on the Western Australian continental margin and that environmental gradients are correlated with distributions of benthic marine invertebrates. Identifying biogeographical regions based on these methods has the potential to inform management across a broad range of environments.
Are conservation biologists working too hard?
Source:Biological Conservation, Volume 166
Author(s): Ahimsa Campos-Arceiz , Lian Pin Koh , Richard B. Primack
The quintessential scientist is exceedingly hardworking and antisocial, and one who would spend countless evenings and weekends buried under her/his microscopes and manuscripts. In an attempt to bust this popular myth, we analyzed the work habits of conservation biologists using data from Biological Conservation’s online manuscript submission system, which includes more than 10,000 manuscript submissions and almost 15,000 reviews from between 2004 and 2012. We found that 11% of new manuscripts and 12% of manuscript reviews were submitted on weekends. Weekend submission rates increased by 5% and 6% for new manuscripts and reviews respectively per year during the study period. Chinese and Indian biologists worked the most on weekends compared to their colleagues elsewhere, submitting 19% of their manuscripts on Saturdays and Sundays. At the other end of the spectrum, Belgians and Norwegians submitted only 4% of manuscripts on weekends. Czech and Polish biologists were the most assiduous weekend reviewers, submitting 27% and 25% of reviews on weekends, respectively. Irish and Belgian reviewers worked the least on weekends, submitting only 6% of reviews during that time. Sixteen percent of new manuscripts were submitted on weekdays after regular office hours – between 19:00pm and 07:00 am – with the highest rate of nighttime submissions by Japanese (30%), Mexican (26%) and Brazilian (22%) scientists. Finnish, South African and Swiss researchers, however, submitted only 9%, 10%, and 10% of new manuscripts after regular working hours. In general, our results suggest that conservation biologists work extensively on weekends and at night, that the trend for working on weekends is increasing over time, and that these patterns have strong geographical structure. These habits could have negative impacts on the quality of the work as well as on the life-work balance of conservation scientists. Universities and other scientific organizations should allocate more time during regular work hours for scientists to complete their research duties, including the submission and review of manuscripts.
Is the connectivity of the Natura 2000 network better across internal or external administrative borders?
Source:Biological Conservation, Volume 166
Author(s): Otars Opermanis , Brian MacSharry , Douglas Evans , Zelmira Sipkova
The lack of coherence of a network of protected areas across administrative borders may occur as different bodies are responsible for nature conservation on either side which may lead to a lack of unified approaches in site selection. In the European Union such a situation is possible not only across international borders but also across borders of provinces of those countries which have strong legislative internal powers. We obtained robust estimates of spatial connectedness and functional connectivity, the latter based on presence of the same species in Natura 2000 sites adjoining across internal borders, between federal states of Austria and Germany and autonomous provinces of Italy and Spain.Network connectedness across internal borders in Germany, Italy and Spain showed a similar logical pattern with means over 75% and most values were higher than connectedness measures of international borders. In Austria we found no clear pattern: connectedness measures both of internal and external borders varied greatly. Network connectivity across internal borders was typically poorer than connectedness and poorer than connectivity of international borders of the same countries: we provide a number of possible explanations for that. The poor connectedness of the Austrian Natura 2000 network across internal borders is linked with the absence of coordination of Natura 2000 site designation at the national level. We believe this study could be interesting for other (large) countries worldwide with similar de-centralisation of nature conservation administration.
Using species distribution modelling to disentangle realised versus potential distributions for rare species conservation
Source:Biological Conservation, Volume 166
Author(s): Arnald Marcer , Llorenç Sáez , Roberto Molowny-Horas , Xavier Pons , Joan Pino
Range maps provide important information in species conservation management, specially in the case of rare species of conservation interest. For the vast majority of cases, this information can only be estimated by means of species distribution modelling. When absence data is unavailable, modelled distribution maps represent the spatial variation of the degree of suitability for the species rather than their realised distribution. Although discerning potentially suitable areas for a given species is an important asset in conservation, it is necessary to estimate current distributions in order to preserve current populations. This work explores the use of species distribution modelling (Maxent) for species of conservation interest when their Extent of Occurrence (EOO) is well-known and there is quality occurrence data. In this case, derived binary maps of potentially suitable areas can be obtained and used to assess the conservation and protection status of a given species in combination with the EOO and existing protected area networks. Seven species, which are rare and endemic to the Western Mediterranean, have been used as an example. Valuable information for conservation assessment such as potentially suitable areas, EOO, Areas of Occupancy (AOO) and degree of protection is provided for this set of species. In addition, the existing informal view that among experts these species have range sizes much smaller than their potentially suitable area is confirmed. This could probably be attributed to important but currently unknown predictor variables and to historical phylogeographic factors.
Provisional agenda for Expert Workshop on the Conceptual Framework for IPBES now available
The provisional agenda for Expert Workshop on the Conceptual Framework for IPBES is now available from here. The workshop will be held back to back with the second full Bureau and MEP meeting, from Sunday 25 - Monday 26 August 2013 in Cape Town, South Africa. The workshop is for invited participants only.
The ecology of differences: assessing community assembly with trait and evolutionary distances
Abstract
Species enter and persist in local communities because of their ecological fit to local conditions, and recently, ecologists have moved from measuring diversity as species richness and evenness, to using measures that reflect species ecological differences. There are two principal approaches for quantifying species ecological differences: functional (trait-based) and phylogenetic pairwise distances between species. Both approaches have produced new ecological insights, yet at the same time methodological issues and assumptions limit them. Traits and phylogeny may provide different, and perhaps complementary, information about species' differences. To adequately test assembly hypotheses, a framework integrating the information provided by traits and phylogenies is required. We propose an intuitive measure for combining functional and phylogenetic pairwise distances, which provides a useful way to assess how functional and phylogenetic distances contribute to understanding patterns of community assembly. Here, we show that both traits and phylogeny inform community assembly patterns in alpine plant communities across an elevation gradient, because they represent complementary information. Differences in historical selection pressures have produced variation in the strength of the trait-phylogeny correlation, and as such, integrating traits and phylogeny can enhance the ability to detect assembly patterns across habitats or environmental gradients.
Reliable, verifiable and efficient monitoring of biodiversity via metabarcoding
Abstract
To manage and conserve biodiversity, one must know what is being lost, where, and why, as well as which remedies are likely to be most effective. Metabarcoding technology can characterise the species compositions of mass samples of eukaryotes or of environmental DNA. Here, we validate metabarcoding by testing it against three high-quality standard data sets that were collected in Malaysia (tropical), China (subtropical) and the United Kingdom (temperate) and that comprised 55,813 arthropod and bird specimens identified to species level with the expenditure of 2,505 person-hours of taxonomic expertise. The metabarcode and standard data sets exhibit statistically correlated alpha- and beta-diversities, and the two data sets produce similar policy conclusions for two conservation applications: restoration ecology and systematic conservation planning. Compared with standard biodiversity data sets, metabarcoded samples are taxonomically more comprehensive, many times quicker to produce, less reliant on taxonomic expertise and auditable by third parties, which is essential for dispute resolution.