摘要
发表于 2025-3-23 10:16:00
Plants in communities and their distributionsther plants and animals that share the land with it. The pressures of living in a community, together with the adaptations to the non-living habitat factors dealt with above, are selective determinants in the evolution of the general range and size of a species. Within this general range, each indiv
AND
发表于 2025-3-23 14:22:29
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暂时中止
发表于 2025-3-23 20:14:58
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FOIL
发表于 2025-3-24 01:17:12
Tropical formations with conspicuous grasslands: savannasominated formation with a greater or lesser proportion of open woody vegetation and associated trees. In the USA, the word ‘savanna’ is not confined in its usage to tropical formations. These rather vague definitions have challenged a number of authors to define the vegetation type more precisely. W
OFF
发表于 2025-3-24 05:02:44
The temperate deciduous forestse, even in relatively recently settled North America, so that only remnants remain from which to piece together their original character. Some fragments, such as the much-studied cove hardwood forests of Tennessee, are richer in species than others, so that conclusions about their ecology may not be
奖牌
发表于 2025-3-24 08:04:44
The coniferous forests of the Northern Hemisphereard of North America, lands with cool, very damp climates have extensive coniferous forests. In mountainous regions, the sub-alpine stages are dominated by conifers. There are extensive coniferous forests in Brazil and they are important in the Mediterranean Basin. Clearly all these types are not of
Exploit
发表于 2025-3-24 10:46:24
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Ornithologist
发表于 2025-3-24 16:00:03
Adaptations and selective factors: an introduction altitude, where there is chronic aridity and where the land meets either salt water or permanently flooded ground. The particular stresses that these environments impose on plant life have been strong selective forces in evolution, so that highly specialized kinds of vegetation have developed with
Phagocytes
发表于 2025-3-24 22:42:54
Vegetation of arid landsworld’s land surface (Fig. 15.1). However, to define them precisely is not easy. Rainfall alone cannot be used, as they cover tropical and temperate lands with very different evaporation rates. The various indirect criteria that have been proposed — the presence of lakes with no outflow, intermitten
充气女
发表于 2025-3-25 03:04:20
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