58 research outputs found
Cultivar diversity as a means of ecologically intensifying dry matter production in a perennial forage stand
The relationship between genotypic diversity and productivity has not been adequately explored in perennial forage production systems despite strong theoretical and empirical evidence supporting diversity\u27s role in ecosystem functioning in other managed and unmanaged systems. We conducted a two-year field experiment with six cultivars of an agriculturally important forage grass, Lolium perenne L. (perennial ryegrass). Dry matter production of L. perenne and the weed community that emerged from the soil seed bank were measured each year in treatments that ranged from cultivar monocultures to three- and six-way cultivar mixtures, all sown at a constant seeding rate. Mean L. perenne dry matter production increased with increasing cultivar diversity and was highest in mixtures that contained cultivars representing the greatest additive trait range (calculated on rankings of three traits: winter hardiness, heading date, and tolerance to grazing). Mixtures had greater yields than those predicted by the mean of their component monoculture yields, but there was evidence that highly productive cultivars may have dampened over-yielding in mixtures. Weed abundance was correlated with L. perenne dry matter, but not L. perenne cultivar diversity. These results suggest that multi-cultivar mixtures may have utility as an approach to ecologically intensifying perennial forage production. Additional research will be necessary to determine the mechanisms responsible for the over-yielding observed in this study and the generality of these findings
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Potential impacts of climate change on agriculture and fisheries production in 72 tropical coastal communities
Climate change is expected to profoundly affect key food production sectors, including fisheries and agriculture. However, the potential impacts of climate change on these sectors are rarely considered jointly, especially below national scales, which can mask substantial variability in how communities will be affected. Here, we combine socioeconomic surveys of 3,008 households and intersectoral multi-model simulation outputs to conduct a sub-national analysis of the potential impacts of climate change on fisheries and agriculture in 72 coastal communities across five Indo-Pacific countries (Indonesia, Madagascar, Papua New Guinea, Philippines, and Tanzania). Our study reveals three key findings: First, overall potential losses to fisheries are higher than potential losses to agriculture. Second, while most locations (> 2/3) will experience potential losses to both fisheries and agriculture simultaneously, climate change mitigation could reduce the proportion of places facing that double burden. Third, potential impacts are more likely in communities with lower socioeconomic status
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How Good Science and Stories Can Go Hand-In-Hand
What do you say when you have only a minute to explain to a municipal official why keeping track of the number of bird species found in a park may help make decisions about park management? Talk of significant differences among treatments or testing theory will likely meet with glazed looks. In contrast, sharing the stories of the citizen scientists who have censused the birds year after year makes the information more personal and more salient.
Stories bring conservation science to life. When one hears how Trevor Lloyd Evans, indefatigable director of bird banding at Manomet Center for Conservation Sciences, awoke before dawn every morning, rain or shine, and led his team of volunteer banders in their mist‐netting surveys, as he has done every spring and fall for more than 40 years; how spring migrants arrive earlier than they used to; and how magical the day was when volunteers mist‐netted a Golden‐winged Warbler (Vermivora chrysoptera), a species not captured in over a decade, the significance of the issues, the contributions of science, and possible solutions become much clearer (Manomet Center 2012). We can explain, through Trevor's story, how assessments of ecosystem health are informed by long‐term observations and deep knowledge of natural and human history in particular places.
Here, however, we focus on the complementary roles stories can play, together with science, in advancing conservation science and practice. We assert that conservation interventions that recognize the synergies between science and storytelling may achieve more substantial biological and social outcomes than those that rely on only one or the other. In our work as conservation scientists, we have observed at least 3 types of synergy between stories and science: stories convey the significance of our science (communication), stories can serve as data (scholarship), and stories illustrate how scientific knowledge can illuminate policy choices (translation). We illustrate these synergies with a story from Cabo Pulmo, a national park in Mexico's Baja California Sur.Keywords: Gulf of California, Conservation science, Ecosystem services, Biodiversit
Empirical Models of Transitions between Coral Reef States: Effects of Region, Protection, and Environmental Change
There has been substantial recent change in coral reef communities. To date, most analyses have focussed on static patterns or changes in single variables such as coral cover. However, little is known about how community-level changes occur at large spatial scales. Here, we develop Markov models of annual changes in coral and macroalgal cover in the Caribbean and Great Barrier Reef (GBR) regions
Effects of ecosystem protection on scallop populations within a community-led temperate marine reserve
This study investigated the effects of a newly established, fully protected marine reserve on benthic habitats and two commercially valuable species of scallop in Lamlash Bay, Isle of Arran, United Kingdom. Annual dive surveys from 2010 to 2013 showed the abundance of juvenile scallops to be significantly greater within the marine reserve than outside. Generalised linear models revealed this trend to be significantly related to the greater presence of macroalgae and hydroids growing within the boundaries of the reserve. These results suggest that structurally complex habitats growing within the reserve have substantially increased spat settlement and/or survival. The density of adult king scallops declined threefold with increasing distance from the boundaries of the reserve, indicating possible evidence of spillover or reduced fishing effort directly outside and around the marine reserve. However, there was no difference in the mean density of adult scallops between the reserve and outside. Finally, the mean age, size, and reproductive and exploitable biomass of king scallops were all significantly greater within the reserve. In contrast to king scallops, the population dynamics of queen scallops (Aequipecten opercularis) fluctuated randomly over the survey period and showed little difference between the reserve and outside. Overall, this study is consistent with the hypothesis that marine reserves can encourage the recovery of seafloor habitats, which, in turn, can benefit populations of commercially exploited species, emphasising the importance of marine reserves in the ecosystem-based management of fisheries
Factors Influencing Environmentally Responsible Behavior among Coastal Recreationists
An increasing threat to the marine environment is the presence of debris in the ocean, which is predominantly a result of land-based sources and increasing use of single-use packaging items. To begin reducing the amount of debris entering the ocean, human behavior must be addressed. The purpose of this study is to evaluate how coastal recreationists behave towards the environment and whether their participation in recreation correlates to their reported behavior specific to marine debris control. Path analysis was used to determine how one’s attitudes, knowledge, recreational activity, and background characteristics influence behavior. Results showed that type of recreational activity had very little impact on behavior and other predictors. From the model, marine environmental concern, connection to the marine environment, and gender most directly influenced reported behavior. Therefore, to encourage change in recreationists’ relevant behavior, the results indicate social groups where behavior change efforts could initially be made. Additionally, the marine environmental concerns of different demographic groups should be considered and used in developing programs directed at increasing environmentally responsible behavior with emphasis on marine debris
Fishing Farmers: Fishing, Livelihood Diversification and Poverty in Rural Laos
The relationship between fishing, livelihood diversification and poverty was investigated in the lower Mekong basin, in Laos, where fishing forms an important, but usually secondary part of rural livelihoods. Results from a household survey show that participation in fishing is common and positively associated with higher occupational diversity and more agricultural activities. This is likely due to the low opportunity costs associated with many forms of fishing and factors such as tradition, enjoyment of fishing, underutilised labour and low capital requirements. Alternative livelihoods within the rural setting are therefore unlikely to cause fishers to leave the fishery, but instead strengthen the livelihood portfolio as a supplementary activity. Fishing is not an activity only for the very poorest households, but is undertaken by all wealth groups. However, fishing forms a greater proportion of income, employment and food security for the poor and is important in households with poor quality farm land
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