 |
| Title | Size | Date | Provider | Folder |
 | Navigating protected areas as social-ecological systems: integration pathways of French nature reserves
On a global scale, protected areas (PAs) are one of the main tools used for biodiversity conservation. However, accelerated biodiversity loss and lack of social acceptance of PAs call into question their ability to reach long-term biodiversity conservation objectives. To address this, conservation scientists and practitioners have moved from segregative to integrative models of PAs. When the segregative model sees PAs as human exclusion zones, the integrative model considers conservation and development projects and multiple partnerships with local stakeholders within and outside PAs. Given this paradigmatic evolution, a PA and its surrounding landscape are increasingly regarded as a single social-ecological system (SES). This development brings new challenges for conservationists: How should these complex and dynamic systems be managed, and how can their pathways be described and piloted? Using French nature reserves (NRs) as case studies, we propose a framework for analyzing the integration pathways of PAs within their social-ecological context. We identified the pathways of 10 NRs according to their degree of integration in the surrounding landscape (spatial), their management objectives (sectoral), and their governance systems (institutional). We analyzed these pathways using three metaphors associated with resilience thinking (adaptive cycle, adaptation, and transformation). We discussed how these 10 NRs have changed over time, revealing how practitioners anticipate future pathways and avoid undesirable states. Through an exploration of the totality of an SES’s spatial, sectoral, and institutional pathways, the framework we propose is a potential tool for identifying opportunities and constraints for long-term conservation actions. | 1007.99KB | 31.01.2018 | Margarita Grudova | Scales Relevant Scientific Papers | |
 |
| Scale-specific spatial density dependence in parasitoids: a multi-factor meta-analysis
Summary
Within a landscape, the risk of an insect being attacked by a parasitoid varies with the local density of the host species. This relationship should be strongest when observed at medium extents and resolutions with respect to parasitoids’ foraging range, and turn negative at fine resolutions. The relationship is also hypothesized to depend on certain traits of the host and parasitoid taxa – for example being more positive for more specialized hosts or parasitoids and more negative for mobile hosts or gregarious parasitoids. Building on earlier literature reviews, it is now possible to investigate these hypotheses using meta-analysis.
We performed a multi-factor meta-analysis on 151 analyses of parasitism rates with respect to host densities at specified scales, from 61 empirical studies published from 1988 to 2012. We explored how the correlation between host density and parasitism rate may be related to the explanatory variables already mentioned, plus parasitoid body length and various other characteristics of both hosts and parasitoids.
Correlations (Pearson\'s r) between host density and parasitism rate ranged from –0·88 to 0·98 (mean 0·16, standard deviation 0·39). The correlation was more often negative where the host was exotic or in the orders Lepidoptera or Diptera, where the parasitoid was larger or exotic, or where the study was conducted at a finer grain size. Hymenoptera and Homoptera were the most likely host orders to reveal positive associations, with Coleoptera and Diptera intermediate.
The fact that increased observational grain size had similar effects to decreased parasitoid body length could be taken as evidence that parasitoids’ foraging ranges increase with their body length. However, the hypothesis about scale-specific foraging was not supported by studies that compared multiple scales.
We conclude that parasitism most commonly produces positive (compensatory) spatial density dependence, but ecological context is all-important. These findings should help improve the design and interpretation of field experiments on parasitism as well as their application to the modelling of population dynamics and the practice of biological control. | 215.27KB | 03.02.2016 | Margarita Grudova | Scales Relevant Scientific Papers | |
|
| SCHWEIGER_increasing range mismatching_interacting species_global change_Supplementary information
SCHWEIGER_increasing range mismatching_interacting species_global change_Supplementary information | 1012.28KB | 30.03.2015 | Margarita Grudova | Scales Relevant Scientific Papers | |
|
| Between Geometry and Biology: The Problem of Universality of the Species-Area Relationship
The species-area relationship (SAR) is considered to be
one of a few generalities in ecology, yet a universal model of its shape
and slope has remained elusive. Recently, Harte et al. argued that
the slope of the SAR for a given area is driven by a single parameter,
the ratio between total number of individuals and number of species
(i.e., the mean population size across species at a given scale). We
provide a geometric interpretation of this dependence. At the same
time, however, we show that this dependence cannot be universal
across taxa: if it holds for a taxon composed from two subsets of
species and also for one of its subsets, it cannot simultaneously hold
for the other subset. Using three data sets, we show that the slope
of the SAR considerably varies around the prediction. We estimate
the limits of this variation by using geometric considerations, providing
a theory based on species spatial turnover at different scales.
We argue that the SAR cannot be strictly universal, but its slope at
each particular scale varies within the constraints given by species’
spatial turnover at finer spatial scales, and this variation is biologically
informative. | 470.03KB | 30.03.2015 | Margarita Grudova | Scales Relevant Scientific Papers | |
|
| A meta-analysis of dispersal in butterflies
Dispersal has recently gained much attention because of its crucial role in the conservation and evolution of species facing major environmental changes such as habitat loss and fragmentation, climate change, and their interactions. Butterflies have long been recognized as ideal model systems for the study of dispersal and a huge amount of data on their ability to disperse has been collected under various conditions. However, no single ‘best’ method seems to exist leading to the co-occurrence of various approaches to study butterfly mobility, and therefore a high heterogeneity among data on dispersal across this group. Accordingly, we here reviewed the knowledge accumulated on dispersal and mobility in butterflies, to detect general patterns. This meta-analysis specifically addressed two questions. Firstly, do the various methods provide a congruent picture of how dispersal ability is distributed across species? Secondly, is dispersal species-specific? Five sources of data were analysed: multisite mark-recapture experiments, genetic studies, experimental assessments, expert opinions, and transect surveys. We accounted for potential biases due to variation in genetic markers, sample sizes, spatial scales or the level of habitat fragmentation. We showed that the various dispersal estimates generally converged, and that the relative dispersal ability of species could reliably be predicted from their relative vagrancy (records of butterflies outside their normal habitat). Expert opinions gave much less reliable estimates of realized dispersal but instead reflected migration propensity of butterflies. Within-species comparisons showed that genetic estimates were relatively invariable, while other dispersal estimates were highly variable. This latter point questions dispersal as a species-specific, invariant trait. | 738.4KB | 30.03.2015 | Margarita Grudova | Scales Relevant Scientific Papers | |
|
|
Document Library