نتایج جستجو برای: overexploitation
تعداد نتایج: 943 فیلتر نتایج به سال:
15 The endemic pine, Pinus canariensis, forms one of the main forest ecosystems in the 16 Canary Islands. In this archipelago, pine forest is a mosaic of natural stands (remnants 17 of past forest overexploitation) and artificial stands planted from the 1940’s. The 18 genetic makeup of the artificially regenerated forest is of some concern. The use of 19 reproductive material with uncontrolled ...
The high diversity of mutualisms has probably limited the development of a general theory about their evolution and their stability. Here we review conflicts of interests occurring in the 13 known nursery pollination systems, where pollinators reproduce within the inflorescence they pollinate. We found three main conflicts of interest between mutualists that correspond to the following evolutio...
The large amount of money spent and the great number of travelers depicts the importance of tourism. Tourists travel to and from all areas around both hemispheres searching for a variety of experiences. Tourism industry has developed positively and has increased in different ways, regarding its type or scale. Therefore, tourists and tourism industry develop accordingly and frequently very fast,...
Hatcheries constitute nowadays the only viable solution to support the husbandry of bivalve molluscs due to the depletion and/or overexploitation of their natural beds. Hatchery activities include the broodstock conditioning and spawning, rearing larvae and spat, and the production of microalgae to feed all stages of the production cycle. However, outbreaks of disease continue to be the main bo...
Decalepis hamiltonii. Wight and Arn. (Asclepiadaceae) has been extensively used in traditional systems of medicine for a wide range of ailments. Phytochemical studies have shown the presence of many valuable compounds such as saponins, tannins, flavonoids, phenolics, triterpenes, ketones, aldelydes, resinol, sterols, inositol, fatty acids, volatile flavour compounds, cardiac glycosides, volatil...
Identifying hotspots of species threat has been a successful approach for setting conservation priorities. One important challenge in conservation is that, in many hotspots, export industries continue to drive overexploitation. Conservation measures must consider not just the point f impact, but also the consumer demand that ultimately drives resource use. To understand which species threat hot...
From the pioneering explorations of Joseph Banks (later a President of the Royal Society), to the present day, a great deal has been learnt about the extent, distribution and stability of biological diversity in the world. We now know that diverse life can be found even in the most inhospitable places. We have also learned that biological diversity changes through time over both large and small...
Amphibians are considered reliable indicators of environmental quality. In the western United States, a general decline of frog populations parallels an apparent worldwide decline. The factors thought to be contributing to declines in frog populations include habitat loss, introduction of exotic species, overexploitation, disease, climate change, and decreasing water quality. With respect to wa...
This article examines how environmental degradation of fisheries resources in the context of Mauritius is linked up with human investment in education, economic growth, and income inequality. Empirical evidence shows that public-sector investment in education promotes economic growth, but at the expense of greater inequality of income. Among the vulnerable groups affected by this type of develo...
The importance of aquaculture in the fishery sector is increasing. The growth of aquaculture complements the stagnant growth of extractive fisheries. Many countries are now entering this emerging economic activity. This positive feature has some serious drawbacks when the country has no local institutions to ensure the environmental sustainability of aquaculture. The Chilean salmon farming indu...
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