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51.
52.
Paul Laris 《Human ecology: an interdisciplinary journal》2002,30(2):155-186
Data are presented indicating a seasonal mosaic pattern of burning in the savanna of southern Mali. A seasonal mosaic is a landscape that is annually re-created by people, and which contains patches of unburned, early burned, and recently burned vegetation. A survey of over 100 farmers and in-depth interviews demonstrates that rural inhabitants of southern Mali begin an annual burning regime early in the dry season in order to fragment the landscape, with the goal of preventing later fires that can damage natural resources. The process of gradually burning off the driest vegetation creates a seasonal mosaic of habitat patches that increases the potential of the landscape for a variety of dry season land uses, including hunting, gathering of savanna products, and grazing. An analysis of a series of Landsat images shows that the practice of mosaic burning is widespread in the wooded savanna, in which burning usually begins early and large fires are rare. On the basis of recent developments in ecological theory and empirical evidence from similar burning regimes in parts of Australia, it is suggested that seasonal mosaic burning in Mali not only prevents damaging late-season fires but increases biodiversity. It is concluded that discourse on African savanna burning overemphasizes the ecologically detrimental aspects of fire, while neglecting the beneficial ones resulting in misguided policies that pose a threat to human livelihoods and savanna ecosystems. 相似文献
53.
Rye bread and synthetic bread odorants – effective trap bait and lure for German cockroaches 下载免费PDF全文
Bread‐in‐beer and bread‐in‐water are prevalent home recipe trap baits for attracting German cockroaches (GCRs), Blattella germanica (L.) (Dictyoptera: Blattellidae), which are significant urban pests. Our objectives were to (1) test the attractiveness of these baits, (2) study the underlying factors of GCR attraction, and (3) determine whether a blend of synthetic bread odorants could replace bread in a trap lure. In large‐arena laboratory experiments with laboratory‐reared GCR males, traps baited with rye bread not only captured eightfold more males than unbaited control traps but also most males released into bioassay arenas. Neither beer nor water enhanced the attractiveness of bread. Bread crust as a bait was more effective than bread crumbs. As Porapak Q headspace volatile extracts of rye bread attracted GCRs, all rye bread odorants in extracts were identified by gas chromatography‐mass spectrometry. Synthetic rye bread odorants and other known bread odorants were then assembled into a master blend. This master blend, and even partial blends lacking certain groups of organic volatiles such as aldehydes and ketones, proved very attractive to GCRs. We conclude that rye bread could be used as an effective bait in retainer traps or, laced with insecticide, as a food source in bait stations. A lure of synthetic bread odorants may eventually replace bread as bait, but the minimum number of essential odorants for that lure has yet to be determined. 相似文献
54.
What about cultural ecosystems? Opportunities for cultural considerations in the “International Standards for the Practice of Ecological Restoration” 下载免费PDF全文
The Society for Ecological Restoration's 2016 (SER) “International Standards for the Practice of Ecological Restoration” is a living document intended to guide restoration projects “anywhere in the world.” Given its intended global scope and in hopes of informing future editions, this document is critically assessed in light of the role people have played in ecosystems around the world. We argue that the Standards has an underlying nature–culture dichotomization that limits its applicability; in qualifying what it calls “cultural ecosystems” for rehabilitation, rather than restoration, the Standards privileges colonial visions of ecological restoration. We also discuss the Standards' representation of the ecological impacts and practices of indigenous groups. Whereas the Standards claims that preindustrial cultural ecosystems exist in states similar to unmodified areas, many historians, anthropologists, and paleoecologists would point out that preindustrial people sometimes had massive environmental impacts through agriculture, hydrological engineering, over‐hunting, living in dense urban environments, transporting species, burning on a scale capable of changing the climate, and other practices. Furthermore, the Standards does not discuss how the cultural goals of indigenous groups fit into the overall picture of ecological restoration. Future drafts of the Standards should more accurately frame the diverse roles people play in nature, and create global standards that account for the validity of cultural goals for ecological restoration. 相似文献
55.
Deirdre Howard-Wagner 《Ethnic and racial studies》2018,41(7):1332-1351
Thinking about the governance of Indigenous poverty as an economic, social and racial project, the paper offers a way of understanding the dynamics of Indigenous policy formation in Australia in the neo-liberal age as what Howard Winant first coined a racial formation. In providing this analysis, this paper sits alongside a small, but growing body of work that reveals the racialized effects of governing through poverty in the neo-liberal age. 相似文献
56.
Cultural, practical, and economic value of wild plants: A quantitative study in the Bolivian Amazon 总被引:4,自引:0,他引:4
Victoria Reyes-García Tomás Huanca Vincent Vadez William Leonard David Wilkie 《Economic botany》2006,60(1):62-74
Researchers have developed several indices to estimate the significance of plant species for humans. We build on previous
methods in ethnobotany and anthropology to develop a new way to value plant species along three dimensions: cultural, practical,
and economic. We used interview and observational data on the use of wild plants by the Tsimane’, a foraging-horticultural
society in the Bolivian Amazon. We calculated the cultural, practical, economic, and total values of 114 plant species from
46 families. We found a low correlation between the practical and the cultural values of species: some species rarely used
were frequently mentioned in interviews, whereas some species frequently used were rarely mentioned in interviews. Indices
of cultural, practical, and economic value measure different dimensions of the importance of plant species to society. The
combination of the three indices offers a more comprehensive valuation of the significance of plants for humans than the use
of only one index. 相似文献
57.
Japanese freshwater fishes, including lampreys, comprise 15 orders, 35 families, and 96 genera, with 211 species and subspecies. Most belong to the families Cyprinidae (29% of species and subspecies), Gobiidae (21%), Salmonidae (10%), and Cobitidae (8%). Cyprinids and cobitids presumably originated from east Asia, gobiids from southeast Asia, and cottids and salmonids from the north Pacific. Japanese freshwater fishes include 88 endemic species and subspecies, of which three have been extirpated. Fishes introduced into natural rivers and lakes for inland commercial fisheries and sport fishing, and by accident, include many exotic species, of which 23 now inhabit natural freshwaters. These often have destroyed the local fish fauna by predation, and caused genetic pollution by hybridization with local strains. Destruction of freshwater environments by land development also poses a threat to Japanese freshwater fish communities. In addition Japanese freshwater systems have been markedly altered by development of rice paddy fields which have caused some species to decline but others to flourish, and changed the distribution patterns of fishes between upstream and downstream areas. To conserve endangered species and declining communities of Japanese freshwater fishes, we need to clarify the characteristics of their original habitats and the effects of developing paddy fields, from both the ecological and historical points of view. 相似文献
58.
Human introduction or natural dispersion? Atlantic Ocean occurrence of the Indo‐Pacific whitetip reef shark Triaenodon obesus 下载免费PDF全文
H. Bornatowski R. Loose C. L. S. Sampaio O. B. F. Gadig A. Carvalho‐Filho R. R. Domingues 《Journal of fish biology》2018,92(2):537-542
Occurrence of multiple whitetip reef sharks Triaenodon obesus in the Atlantic Ocean is reported for the first time from near a sunken ferry off the Paraná coast in south‐eastern Brazil. This occurrence is hypothesized to have been caused by either a human introduction or a remarkably long oceanic displacement. 相似文献
59.
Three closely related 4-hydroxy-3(2H)-furanones have been found in a range of highly cooked foodstuffs where they are important flavour compounds with aroma threshold values as low as 20 micrograms kg-1 water (approximately 0.14 mumol l-1). The compounds are formed mainly as a result of the operation of the Maillard reactions between sugars and amino acids during heating but one compound, 5-(or 2)-ethyl-2-(or 5)-methyl-4-hydroxy-3(2H)-furanone, appears in practice to be produced by yeast, probably from a Maillard intermediate, during the fermentation stages in the production of soy sauce and beer. The compounds are also important in the flavour of strawberry, raspberry, pineapple and tomato but the route of biosynthesis is unknown. Two 3-hydroxy-2(5H)-furanones, emoxyfuranone and sotolon, which are produced spontaneously from amino acids such as threonine and 4-hydroxy-L-leucine are major contributors to meaty and spicy/nutty flavours in foods. The biosynthesis of 5-(1,2-dihydroxyethyl)-3,4-dihydroxy-2(5H)-furanone (ascorbic acid, vitamin C) and 5-hydroxymethyl-3,4-dihydroxy-2(5H)-furanone (erythroascorbic acid) from sugars in plants and yeast, respectively, has been characterized to the enzymic level. After treatment with chlorine, humic waters contain a range of chloro-furanones, some of which, particularly 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX), are powerful mutagens. The furanones which occur in foods are also mutagenic to bacteria and cause DNA damage in laboratory tests. However, these compounds are, in practice, very effective anti-carcinogenic agents in the diets of animals which are being treated with known cancer-inducing compounds such as benzo[alpha]pyrene or azoxymethane. Two of the food-derived furanones have antioxidant activity comparable to that of ascorbic acid. A biological function has been discovered for some of the furanones besides vitamin C. 5-Methyl-4-hydroxy-3(2H)-furanone is a male pheromone in the cockroach Eurycolis florionda (Walker) and the 2,5-dimethyl derivative deters fungal growth on strawberries and is an important component of the attractive aroma of the fruit. The red seaweed Delisea pulchra (Greville) Montagne produces a range of brominated furanones which prevent colonisation of the plant by bacteria by interfering with the acylated homoserine lactone (AHL) signalling system used by the bacteria for quorum sensing. In addition, these compounds can deter grazing by marine herbivores. It is proposed here that the evolved biological function of a number of furanones is to act as inter-organism signal molecules in several different systems. This has resulted in two coincidental effects which are important for humans. Firstly, the easily oxidized nature of the furanones in general, which is likely to be an important property in their functioning as signal molecules, results in both mutagenic and anti-carcinogenic activity. The balance of these two effects from compounds in the diet has yet to be fully established. Secondly, and more specifically, the 4-hydroxy-3(2H)-furanones associated with fruit aromas act to attract animals to the fruit, which ensures seed dispersal. In the case of humans, the coincidental synthesis of some of these compounds in foods during preparation results in these foods appearing particularly attractive through the transferred operation of the original signalling mechanisms. 相似文献
60.
Modeling Sustainability of Arctic Communities: An Interdisciplinary Collaboration of Researchers and Local Knowledge Holders 总被引:1,自引:0,他引:1
Jack A. Kruse Robert G. White Howard E. Epstein Billy Archie Matt Berman Stephen R. Braund F. Stuart Chapin III Johnny Charlie Sr. Colin J. Daniel Joan Eamer Nick Flanders Brad Griffith Sharman Haley Lee Huskey Bernice Joseph David R. Klein Gary P. Kofinas Stephanie M. Martin Stephen M. Murphy William Nebesky Craig Nicolson Don E. Russell Joe Tetlichi Arlon Tussing Marilyn D. Walker Oran R. Young 《Ecosystems》2004,7(8):815-828
How will climate change affect the sustainability of Arctic villages over the next 40 years? This question motivated a collaboration of 23 researchers and four Arctic communities (Old Crow, Yukon Territory, Canada; Aklavik, Northwest Territories, Canada; Fort McPherson, Northwest Territories, Canada; and Arctic Village, Alaska, USA) in or near the range of the Porcupine Caribou Herd. We drew on existing research and local knowledge to examine potential effects of climate change, petroleum development, tourism, and government spending cutbacks on the sustainability of four Arctic villages. We used data across eight disciplines to develop an Arctic Community Synthesis Model and a Web-based, interactive Possible Futures Model. Results suggested that climate warming will increase vegetation biomass within the herd’s summer range. However, despite forage increasing, the herd was projected as likely to decline with a warming climate because of increased insect harassment in the summer and potentially greater winter snow depths. There was a strong negative correlation between hypothetical, development-induced displacement of cows and calves from utilized calving grounds and calf survival during June. The results suggested that climate warming coupled with petroleum development would cause a decline in caribou harvest by local communities. Because the Synthesis Model inherits uncertainties associated with each component model, sensitivity analysis is required. Scientists and stakeholders agreed that (1) although simulation models are incomplete abstractions of the real world, they helped bring scientific and community knowledge together, and (2) relationships established across disciplines and between scientists and communities were a valuable outcome of the study. Additional project materials, including the Web-based Possible Futures Model, are available at http://www.taiga.net/sustain. 相似文献