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121.
Hasti Daraei Kimia Toolabian Ian Thompson Guanglei Qiu 《Frontiers of Environmental Science & Engineering》2022,16(2):19
122.
Constitutive and induced defenses to herbivory in above- and belowground plant tissues 总被引:3,自引:0,他引:3
A recent surge in attention devoted to the ecology of soil biota has prompted interest in quantifying similarities and differences between interactions occurring in above- and belowground communities. Furthermore, linkages that interconnect the dynamics of these two spatially distinct ecosystems are increasingly documented. We use a similar approach in the context of understanding plant defenses to herbivory, including how they are allocated between leaves and roots (constitutive defenses), and potential cross-system linkages (induced defenses). To explore these issues we utilized three different empirical approaches. First, we manipulated foliar and root herbivory on tobacco (Nicotiana tabacum) and measured changes in the secondary chemistry of above- and belowground tissues. Second, we reviewed published studies that compared levels of secondary chemistry between leaves and roots to determine how plants distribute putative defense chemicals across the above- and belowground systems. Last, we used meta-analysis to quantify the impact of induced responses across plant tissue types. In the tobacco system, leaf-chewing insects strongly induced higher levels of secondary metabolites in leaves but had no impact on root chemistry. Nematode root herbivores, however, elicited changes in both leaves and roots. Virtually all secondary chemicals measured were elevated in nematode-induced galls, whereas the impact of root herbivory on foliar chemistry was highly variable and depended on where chemicals were produced within the plant. Importantly, nematodes interfered with aboveground metabolites that have biosynthetic sites located in roots (e.g., nicotine) but had the opposite effect (i.e., nematodes elevated foliar expression) on chemicals produced in shoots (e.g., phenolics and terpenoids). Results from our literature review suggest that, overall, constitutive defense levels are extremely similar when comparing leaves with roots, although certain chemical classes (e.g., alkaloids, glucosinolates) are differentially allocated between above- and belowground parts. Based on a meta-analysis of induced defense studies we conclude that: (1) foliar induction generates strong responses in leaves, but much weaker responses in roots, and (2) root induction elicits responses of equal magnitude in both leaves and roots. We discuss the importance of this asymmetry and the paradox of cross-system induction in relation to optimal defense theory and interactions between above- and belowground herbivory. 相似文献
123.
A common explanation for hunting in groups is that doing so yields a greater per capita caloric benefit than hunting solitarily.
This is logical for social carnivores, which rely exclusively on meat for energy, but arguably not for omnivores, which obtain
calories from either plant or animal matter. The common chimpanzee, Pan troglodytes, is one of the few true omnivores that regularly hunts in groups. Studies to date have yielded conflicting data regarding
the payoffs of group hunting in chimpanzees. Here, we interpret chimpanzee hunting patterns using a new approach. In contrast
to the classical assumption that hunting with others maximizes per capita caloric intake, we propose that group hunting is
favored because it maximizes an individual’s likelihood of obtaining important micronutrients that may be found in small quantities
of meat. We describe a mathematical model demonstrating that group hunting may evolve when individuals can obtain micronutrients
more frequently by hunting in groups than by hunting solitarily, provided that group size is below a certain threshold. Twenty
five years of data from Gombe National Park, Tanzania are consistent with this prediction. We propose that our ‘meat-scrap’
hypothesis is a unifying approach that may explain group hunting by chimpanzees and other social omnivores. 相似文献
124.
Will Allen Ockie Bosch Margaret Kilvington Don Harley and Ian Brown 《Natural resources forum》2001,25(3):225-233
Adaptive, or 'learning by doing', approaches are often advocated as a means of providing increased understanding within natural resource management. However, a number of organisational and social issues need to be resolved if these approaches are to be used successfully. A case study in the South Island high country of New Zealand is used to review what is needed to support an ongoing community-based monitoring and adaptive management programme. First, the case study is described, paying attention to the social context of the resource management problem. The results of a workshop that explored this problem are then outlined, along with a proposed information flow suggested by participants. Requirements for future steps to resolve these problems (such as information protocols and a multi-stakeholder information system) are discussed. Finally, some broad lessons are drawn from this exercise that could help others developing similar approaches. 相似文献
125.
This work has been the first application of DGT samplers for measuring metals in water and sediment porewater in the Antarctic environment, and whilst DGT water sampling was restricted to quantification of Cd, Fe and Ni, preconcentration using Empore chelating disks provided results for an additional nine elements (Sn, Pb, Al, Cr, Mn, Co, Cu, Zn, As). Although higher concentrations were measured for some metals (Cd, Ni, Pb) using the Empore technique, most likely due to particulate-bound or colloidal species becoming entrapped in the Empore chelating disks, heavy metal concentrations in the impacted Brown Bay were found to be comparable with the non-impacted O'Brien Bay. Sediment porewater sampling using DGT also indicated little difference between Brown Bay and O'Brien Bay for many metals (Cd, Al, Cr, Co, Ni, Cu), however, greater amounts of Pb, Mn, Fe and As were accumulated in DGT probes deployed in Brown Bay compared with O'Brien Bay, and a higher accumulation of Sn was observed in Brown Bay inner than any of the other three sites sampled. Comparison of DGT derived porewater concentrations with actual porewater concentrations showed limited resupply of Cd, Pb, Al, Cr, Mn, Co, Ni, Cu, Zn and As from the solid phase to porewater, with these metals appearing to be strongly bound to the sediment, however, resupply of Fe and Sn was apparent. Based upon our observations here, we suggest that Sn, and to a lesser extent Pb, are critical contaminants. 相似文献
126.
Renewable energy often provokes heated debate on climate change, energy security and the local impacts of developments. However, how far such discussions involve thorough and inclusive debate on the energy and environmental-social justice issues associated with renewable energy siting remains ambiguous, particularly where government agendas prioritise renewable energy and planning systems offer limited opportunities for public debate on value-based arguments for and against renewable energy developments. Using the concept of justice self-recognition, we argue for greater attention to public discussion of the justice dimensions of renewable energy to assist in developing mechanisms to integrate distributive and procedural fairness principles into renewable energy decision-making. To explore how justice is currently invoked in such contexts, we examine recent U.K. policies for renewable energy and public submissions to applications for small-scale wind energy projects in Cornwall, U.K. The analysis of public comments revealed that justice concerns were rarely discussed explicitly. Comments instead did not raise concerns as justice issues or focused implicitly on distributive justice, stressing local aesthetic, community and economic impacts, clean energy and climate change. However, the findings indicated limited discussion of procedural or participatory justice, an absence that hampers the establishment of coherent procedures for deciding acceptable impacts, information standards, public participation and arbitrating disputes. We conclude by suggesting procedural reforms to policy and planning to enable greater public expression of justice concerns and debate on how to negotiate tensions between energy and environmental-social justice in renewable energy siting decisions. 相似文献
127.
David A. Wiedenfeld Allison C. Alberts Ariadne Angulo Elizabeth L. Bennett Onnie Byers Topiltzin Contreras-MacBeath Gláucia Drummond Gustavo A. B. da Fonseca Claude Gascon Ian Harrison Nicolas Heard Axel Hochkirch William Konstant Penny F. Langhammer Olivier Langrand Frederic Launay Daniel J. Lebbin Susan Lieberman Barney Long Zhi Lu Michael Maunder Russell A. Mittermeier Sanjay Molur Razan Khalifa al Mubarak Michael J. Parr Jonah Ratsimbazafy Anders G. J. Rhodin Anthony B. Rylands Jim Sanderson Wes Sechrest Pritpal Soorae Jatna Supriatna Amy Upgren Jean-Christophe Vié Li Zhang 《Conservation biology》2021,35(5):1388-1395
Some conservation prioritization methods are based on the assumption that conservation needs overwhelm current resources and not all species can be conserved; therefore, a conservation triage scheme (i.e., when the system is overwhelmed, species should be divided into three groups based on likelihood of survival, and efforts should be focused on those species in the group with the best survival prospects and reduced or denied to those in the group with no survival prospects and to those in the group not needing special efforts for their conservation) is necessary to guide resource allocation. We argue that this decision-making strategy is not appropriate because resources are not as limited as often assumed, and it is not evident that there are species that cannot be conserved. Small population size alone, for example, does not doom a species to extinction; plants, reptiles, birds, and mammals offer examples. Although resources dedicated to conserving all threatened species are insufficient at present, the world's economic resources are vast, and greater resources could be dedicated toward species conservation. The political framework for species conservation has improved, with initiatives such as the UN Sustainable Development Goals and other international agreements, funding mechanisms such as The Global Environment Facility, and the rise of many nongovernmental organizations with nimble, rapid-response small grants programs. For a prioritization system to allow no extinctions, zero extinctions must be an explicit goal of the system. Extinction is not inevitable, and should not be acceptable. A goal of no human-induced extinctions is imperative given the irreversibility of species loss. 相似文献
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130.
Future Taxonomic Partnerships: Reply to Goldstein 总被引:1,自引:0,他引:1