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901.
Verena Rodorff Liron Steinmetz Jan Mertens Marianna Siegmund-Schultze Johann Köppel 《Regional Environmental Change》2018,18(7):1983-1997
In Brazil’s semi-arid Northeast, most rural dwellers derive income from the dry Caatinga forest through livestock farming, fruit collection, and firewood extraction. However, recurring droughts and inadequate land use practices jeopardize farmers’ livelihoods. The drought-resistant, endemic Umbuzeiro tree provides fruit for direct consumption and allows for the creation of transformed products. The planting of this native species can enhance the well-being of the ecosystem and establish future benefits for smallholdings. However, it is crucial that when taking up innovative practices to cope with environmental change, a willingness to apply them should be fostered among local farmers. We used constellation analysis as a transdisciplinary approach to identify elements of current land management which subsequently defined the nodes of a Bayesian network (BN). We developed probabilities of practice uptake that strengthen success, namely the conservation of natural resources while securing the incomes of smallholders. In collaboration with stakeholders and experts, 25 identified nodes for the BN were tested under various scenarios. Adopting all suggested innovative practices secures the final objectives—ecosystem health and farmer benefits (approx. 90%). The analysis quantified the relevance of single issues that may impede farmers to adopt the practices, such as having to cultivate seedlings or avoiding long-term investments. Further crucial actions include the fencing-off of livestock and marketing pathways. Affordable credit, research, and supportive farmers’ institutions can encourage farmers to implement innovative practices. The use of modeled scenarios can provide evidence, which might encourage sustainable land management. 相似文献
902.
903.
Jonathan C. P. Reum P. Sean McDonald W. Christopher Long Kirstin K. Holsman Lauren Divine David Armstrong Jan Armstrong 《Conservation biology》2020,34(3):611-621
The development of species recovery plans requires considering likely outcomes of different management interventions, but the complicating effects of climate change are rarely evaluated. We examined how qualitative network models (QNMs) can be deployed to support decision making when data, time, and funding limitations restrict use of more demanding quantitative methods. We used QNMs to evaluate management interventions intended to promote the rebuilding of a collapsed stock of blue king crab (Paralithodes platypus) (BKC) around the Pribilof Islands (eastern Bering Sea) to determine how their potential efficacy may change under climate change. Based on stakeholder input and a literature review, we constructed a QNM that described the life cycle of BKC, key ecological interactions, potential climate-change impacts, relative interaction strengths, and uncertainty in terms of interaction strengths and link presence. We performed sensitivity analyses to identify key sources of prediction uncertainty. Under a scenario of no climate change, predicted increases in BKC were reliable only when stock enhancement was implemented in a BKC hatchery-program scenario. However, when climate change was accounted for, the intervention could not counteract its adverse impacts, which had an overall negative effect on BKC. The remaining management scenarios related to changes in fishing effort on BKC predators. For those scenarios, BKC outcomes were unreliable, but climate change further decreased the probability of observing recovery. Including information on relative interaction strengths increased the likelihood of predicting positive outcomes for BKC approximately 5–50% under the management scenarios. The largest gains in prediction precision will be made by reducing uncertainty associated with ecological interactions between adult BKC and red king crab (Paralithodes camtschaticus). Qualitative network models are useful options when data are limited, but they remain underutilized in conservation. 相似文献
904.
Nicola A. Clark Mark Williams Daniel J. Hill Patrick G. Quilty John L. Smellie Jan Zalasiewicz Melanie J. Leng Michael A. Ellis 《Die Naturwissenschaften》2013,100(8):699-722
We evaluate the available palaeontological and geochemical proxy data from bivalves, bryozoans, silicoflagellates, diatoms and cetaceans for sea surface temperature (SST) regimes around the nearshore Antarctic coast during the late Neogene. These fossils can be found in a number of shallow marine sedimentary settings from three regions of the Antarctic continent, the northern Antarctic Peninsula, the Prydz Bay region and the western Ross Sea. Many of the proxies suggest maximum spring–summer SSTs that are warmer than present by up to 5 °C, which would result in reduced seasonal sea ice. The evidence suggests that the summers on the Antarctic shelf during the late Neogene experienced most of the warming, while winter SSTs were little changed from present. Feedbacks from changes in summer sea ice cover may have driven much of the late Neogene ocean warming seen in stratigraphic records. Synthesized late Neogene and earliest Quaternary Antarctic shelf proxy data are compared to the multi-model SST estimates of the Pliocene Model Intercomparison Project (PlioMIP) Experiment 2. Despite the fragmentary geographical and temporal context for the SST data, comparisons between the SST warming in each of the three regions represented in the marine palaeontological record of the Antarctic shelf and the PlioMIP climate simulations show a good concordance. 相似文献
905.
Riske Meijer Henri Bouma Jan Baan Sander E. van der Hurk 《Traffic injury prevention》2019,20(8):16-20
AbstractObjective: The objective of this research is to study the feasibility of measuring behavioral indicators that reflect effects of infrastructure and interaction with other road users.Methods: An observation study was performed using 6 cameras above a separated cycle path next to a road which included a crossing with both cyclists and cars. A learning method based on Single Shot MultiBox Detector was applied to automatically detect the cyclists, and cyclist tracks were determined. Next, kinematic parameters were calculated from the cyclists’ tracks. Amongst others, the cyclists’ intensity, speed, position on the cycle path, and the distance to each other were analyzed for a busy period as well as for a quiet period of the day.Results: With the measurement method developed in this study it is possible to analyze the cyclists’ intensity, the space they use at the cycle path, their average velocity, waiting times, the space and velocity amongst each other, and red light negation. However, collisions were not seen in the dataset analyzed, and the data is not sufficiently accurate to analyze sudden braking actions.Conclusion: It can be concluded that the developed measurement method provides insight of the cyclists’ behavior in such a way that it can already be used for obtaining information to make changes to the infrastructure that will improve the comfort and safety of cyclists. The method could be further developed for doing qualitative comfort and safety analyses, and for doing analyses of the interaction between various types of road participants. 相似文献
906.
Sygna Linda Fuglestvedt Jan S. Aaheim H. Asbjørn 《Mitigation and Adaptation Strategies for Global Change》2002,7(1):45-62
This article looks at the ability of Global Warming Potentials (GWPs) towork as indicators of equivalence for temperature development and damagecosts. We look at two abatement scenarios that are equivalent when using100-year GWPs: one scenario reduces short-lived gases, mainly methane(CH4); the other scenario reduces carbon dioxide (CO2).Despite their equivalence in terms of CO2 equivalents, the scenariosdo not result in equal rates or levels of temperature change. The disparitiescontinue as we move further down the chain of causality toward damagecosts, measured either in terms of rate of climate change or level of climatechange. Compared to the CH4 mitigation scenario, the CO2mitigation scenario gives present value costs 1.3 and 1.5 times higher forlevel- and rate-dependent damage costs, respectively, assuming a discountrate of 3%. We also test the GWPs for other time horizons and theconclusions remain the same; using GWP as an index to reflect equivalentclimate effects and damage costs from emissions is questionable. 相似文献
907.
908.
Identification of sex pheromone components of the pea midge, Contarinia pisi (Diptera: Cecidomyiidae) 总被引:1,自引:0,他引:1
Ylva Hillbur Peter Anderson Heinrich Arn Marie Bengtsson Jan Löfqvist Anthony J. Biddle Olof Smitt Hans-Erik Högberg Ernst Plass Stephan Franke Wittko Francke 《Die Naturwissenschaften》1999,86(6):292-294
Three components in extract of pheromone glands of female pea midges, Contarinia pisi, were found to be active on male pea midge antennae by coupled gas chromatographic-electroantennographic detection. The EAD
active components were identified as 2-acetoxytridecane, (2S,11S)-diacetoxytridecane, and (2S,12S)-diacetoxytridecane. A blend of these compounds proved to be highly attractive to males in windtunnel experiments.
Received: 12 November 1998 / Accepted in revised form: 26 january 1999 相似文献
909.
The Science of Nature - 相似文献
910.
Jan H.A. Boerboom 《Agriculture, ecosystems & environment》1984,11(2):182-183