Search results for "policy"
showing 10 items of 4513 documents
Spatio-Temporal model structures with shared components for semi-continuous species distribution modelling
2017
Abstract Understanding the spatio-temporal dynamism and environmental relationships of species is essential for the conservation of natural resources. Many spatio-temporally sampled processes result in continuous positive [ 0 , ∞ ) abundance datasets that have many zero values observed in areas that lie outside their optimum niche. In such cases the most common option is to use two-part or hurdle models, which fit independent models and consequently independent environmental effects to occurrence and conditional-to-presence abundance. This may be correct in some cases, but not as much in others where the detection probability is related to the abundance. The aim of this work is to infer the…
Low contribution of Caribbean-based researchers to academic publications on biodiversity conservation in the insular Caribbean.
2021
11 pages; International audience; The insular Caribbean is among the most threatened global biodiversity hotspots, warranting urgent and effective action in conservation. However, the capacity of Caribbean-based researchers to address challenges in biodiversity conservation appears limited. To assess the latter, we used the contribution of Caribbean-based authors to the production of peer-reviewed journal papers on biodiversity conservation in the insular Caribbean as a proxy for research capacity. Moreover, because the insular Caribbean is a complex geopolitical system including sovereign states and overseas territories, we examined the contributions of these two groups to the number of pa…
The effect of random and density‐dependent variation in sampling efficiency on variance of abundance estimates from fishery surveys
2019
Abundance indices (AIs) provide information on population abundance and trends over time, while AI variance (AIV) provides information on reliability or quality of the AI. AIV is an important output from surveys and is commonly used in formal assessments of survey quality, in survey comparison studies, and in stock assessments. However, uncertainty in AIV estimates is poorly understood and studies on the precision and bias in survey AIV estimates are lacking. Typically, AIV estimates are “design based” and are derived from sampling theory under some aspect of randomized samples. Inference on population density in these cases can be confounded by unaccounted process errors such as those due …
The aquaculture supply chain in the time of covid-19 pandemic: Vulnerability, resilience, solutions and priorities at the global scale
2022
13 pages, 3 tables, 5 figures
Optimal contract length for biodiversity conservation under conservation budget constraint
2014
We examine the optimal length of a contract period in a conservation program with payments for ecosystem services aiming at protecting biodiversity on privately owned forests. The government chooses the number of stands and the length of contracts so as to maximize biodiversity benefits under a binding conservation budget. We examine the implication of two alternative budgets: a separate budget for each period (periodic budget) or one budget that to be used in all periods (intertemporal budget). The impact of the budget type shows up in the fact that with intertemporal budget choice set is larger and more high quality stands are available for contracting. Based on theoretical characterizati…
A Systematic Literature Review of Historic Garden Management and Its Economic Aspects
2020
Historic gardens are important parts of humanity’s built heritage within the designed landscape, providing many environmental, economic and socio-cultural benefits. Management is a key part of their conservation, perhaps the most difficult because it is costly, must be continual, and requires a skilled workforce. This systematic review looks at the literature addressing historic garden management, with special attention regarding the social, economic and environmental aspects of sustainability. Academic studies on this subject come from many different disciplines, making it both stimulating and fragmented. It is now time to consolidate these interdisciplinary efforts into a clear vision, in…
Global endemics-area relationships of vascular plants
2019
Endemics–Area Relationships (EARs)are fundamental in theoretical and applied biogeography for understanding distribution patterns and promoting biodiversity conservation. However, calculating EARs for vascular plant species from existing data is problematic because of biased knowledge of endemic species distributions and differences between taxonomies. We aimed to overcome these challenges by developing a new standardized global dataset based on expert knowledge to produce a set of global EARs. We developed a nested circle design, with grain sizes of 10 4 , 10 5 , 10 6 , 10 7 , and 10 8 km 2 , respectively, and a global distribution of plots based on a stratified random scheme. The number …
Formalized classification of European fen vegetation at the alliance level
2017
AimsPhytosociological classification of fen vegetation (Scheuchzerio palustris-Caricetea fuscae class) differs among European countries. Here we propose a unified vegetation classification of European fens at the alliance level, provide unequivocal assignment rules for individual vegetation plots, identify diagnostic species of fen alliances, and map their distribution.LocationEurope, western Siberia and SE Greenland.Methods29 049 vegetation-plot records of fens were selected from databases using a list of specialist fen species. Formal definitions of alliances were created using the presence, absence and abundance of Cocktail-based species groups and indicator species. DCA visualized the s…
A conceptual framework for the integral management of marine protected areas
2009
A general conceptual framework for the management of marine protected areas (MPAs) was developed. The driver-pressure-state-impacts-response (DPSIR) framework was used to determine the elements affecting MPAs. The developed evaluation framework helped to select an appropriate suite of indicators to support an ecosystem approach, an assessment of the MPAs functioning and policy decisions. Gaps derived from the management and policy responses in the MPAs were also outlined. It was concluded that the DPSIR framework can help to simplify the complexity of MPA management. This document is a tool for policy makers, scientists and general public on the relevance of indicators to monitor changes an…
Assessing the capacity of different urban forms to preserve the connectivity of ecological habitats
2011
International audience; This paper addresses the relationship between anthropogenic forest habitat fragmentation and the form of urban patterns. Using a two-step methodology we first generate 40 theoretical residential development scenarios following a repeatable procedure; the simulated urban forms are either moderately compact or fractal. Then, we compare the scenarios according to the functional connectivity of the remaining forest habitat using a graph-based approach. The methodology is applied to the urban region of Besançon (France), where forest surfaces are considered as a generic habitat for several animal species. Results obtained show that fractal scenarios of residential develop…