8 research outputs found
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Diversity-Production Relationships of Fish Communities in Freshwater Stream Ecosystems
Aim Ecological relationships between species richness and biomass production are increasingly thought to be pervasive across the globe. Yet, diversity-production relationships have not been explored extensively for freshwater fish communities even though fisheries production provides key services to humans. Our aim was to evaluate the diversity-production relationship of fish communities inhabiting freshwater streams across the Appalachian Mountain range and examine how diversity-production relationships varied across streams possessing different thermal signatures. Location Our study area included 25 freshwater stream ecosystems spanning from Vermont to North Carolina in the United States. Twenty sites were located in Maryland south to Tennessee and North Carolina, while five additional higher latitude sites were sampled in Massachusetts and Vermont. Methods We sampled the 25 study streams from June to September 2012 and collected fish population information to calculate biomass, species richness, the Shannon diversity index and annual production for each fish community. Linear mixed effects models were used to analyse the relationship between diversity indices and total community production. We also compared diversity and production relationships across other taxa. Results Across all streams, community fish production, biomass and P/B ratios ranged from 0.15-6.79 g m(-)(2) y(-)(1), 0.61-0.73 g m(-)(2) and 0.21-1.07 y(-1), respectively. Species richness had a significant positive effect (p = .012) on community fish production, while accounting for the thermal signature of the streams as a random effect and other habitat covariates. The Shannon diversity index did not have a significant effect (p = .101) on community production. Main conclusions The diversity-production relationship observed for stream fish communities was similar to other studies but demonstrated one of the highest slopes. Our results demonstrate that effects of biodiversity resonate to influence the production of fishes; thus, management of fisheries is more closely coupled to biodiversity than previously thought
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Concurrent Sessions A: Passage Effectiveness Monitoring in Small Streams I - Alternatives to Direct Detection for Assessing the Effectiveness of Aquatic Organism Passage
Direct detection of individuals is often considered the most reliable indicator of the effectiveness of aquatic organism passage efforts, but given spatial and temporal variation in movement along with other logistical constraints this detection can be difficult and expensive to obtain, with a high probability of false negatives (concluding no passage when passage is possible). However, the ultimate goal of these projects is to restore population connectivity and increase population resilience. Therefore, we expect that effective aquatic organism passage should be manifest in predictable changes in abundance and genetic structure, which can at the same time serve as indicators of individual movement. Towards this goal we focused on two approaches. First, we used patterns of abundance and diversity above and below road crossings to test whether these patterns could be used to infer passage and connectivity. Second we took advantage of the discrete spawning location strategy used by most stream-dwelling species combined with new tools to assess local genetic structure (via parentage and sibling assignment) to determine whether relatedness structure was consistent with movement and successful dispersal across a potential barrier. For each of these approaches we employed two methods 1) simulation models which define sensitivity, power, and accuracy and 2) field applications which directly test performance. These approaches have been rigorously evaluated in simulations and successfully tested in the field in several locations in the northeastern US and these efforts have helped to define which species, which situations, and which sampling regimes where these techniques will and will not be effective. We are currently working to incorporating these models into assessment frameworks at both site and landscape scales
Agricultura Climáticamente Inteligente en El Salvador
The climate-smart agriculture (CSA) concept reflects an ambition to improve the integration of agriculture development and climate responsiveness. It aims to achieve food security and broader development goals under a changing climate and increasing food demand.
CSA initiatives sustainably increase productivity, enhance resilience, and reduce/remove greenhouse gases (GHGs), and require planning to address tradeoffs and synergies between these three pillars: productivity, adaptation, and mitigation [1]. The priorities of different countries and stakeholders are reflected to achieve more efficient, effective, and equitable food systems that address challenges in environmental, social, and economic dimensions across productive landscapes.
While the concept is new, and still evolving, many of the practices that make up CSA already exist worldwide and are used by farmers to cope with various production risks. Mainstreaming CSA requires critical stocktaking of ongoing and promising practices for the future, and of institutional and financial enablers for CSA adoption.
This country profile provides a snapshot of a developing baseline created to initiate discussion, both within countries and globally, about entry points for investing in CSA at scale
Agricultura Climáticamente Inteligente en Sinaloa, México
The climate-smart agriculture (CSA) concept reflects an ambition to improve the integration of agriculture development and climate responsiveness. It aims to achieve food security and broader development goals under a changing climate and increasing food demand.
CSA initiatives sustainably increase productivity, enhance resilience, and reduce/remove greenhouse gases (GHGs), and require planning to address tradeoffs and synergies between these three pillars: productivity, adaptation, and mitigation [1]. The priorities of different countries and stakeholders are reflected to achieve more efficient, effective, and equitable food systems that address challenges in environmental, social, and economic dimensions across productive landscapes.
While the concept is new, and still evolving, many of the practices that make up CSA already exist worldwide and are used by farmers to cope with various production risks. Mainstreaming CSA requires critical stocktaking of ongoing and promising practices for the future, and of institutional and financial enablers for CSA adoption.
This country profile provides a snapshot of a developing baseline created to initiate discussion, both within countries and globally, about entry points for investing in CSA at scale