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201.
安徽省自然条件优越,野生动物资源丰富,但在资源的开发利用上存在不少问题。只有在科学研究的基础上,把资源的开发利用与保护有机地结合起来,才能实现野生动物资源的永续利用。 相似文献
202.
我国野生蔬菜的开发利用 总被引:5,自引:0,他引:5
本文阐述了我国野生蔬菜的特点、利用现状及其存在的问题,提出了进一步开发利用野生蔬菜的建议. 相似文献
203.
报道了西双版纳纳板河流域自然保护区3个拉祜族村寨对土地和野生植物资源的利用现状,认为转变单纯采集为栽培种植价值大的野生植物是发展的根本出路。 相似文献
204.
205.
喀喇昆仑山-昆仑山地区兽类资源的现状与保护 总被引:10,自引:1,他引:10
本区资源兽类 21种,包括中国Ⅰ级保护动物 5种,Ⅱ级 7种。本区最西段的资源动物以中亚类型为主;自此往东,青藏高原特有种的成分渐增;西昆仑山东段北翼的大型特有兽类的种群数量明显少于南翼。据大型有蹄动物栖息地的面积及其不同分布区域的种群密度,估算本区藏野驴的储量有3.57×104多只,野牦牛3.5×104 只和藏羚9.04×104 只左右。据7月末至8月下旬的观察,藏野驴群体为2—60只(单独个体除外,下同),平均每群9.4只,以2—9只居首位;野牦牛每群2—200多只,平均64只,2—10只及上百只的群体均较常见;藏羚种群大小为2—1000只左右,平均每群38只,以2—5只的群体占优势。某些物种的性比及母幼群中幼羊与母羊的比率等,本文已作记述。在合理保护与利用资源方面所存在的问题,以及今后应采取的保护对策,笔者作了扼要的讨论。 相似文献
206.
在调查统计的基础上,论述了凉山野生食用菌资源的分布状况,及其在改善膳食结构和发展当地经济的重要作用.为了有效保护和持续利用凉山野生菌类资源,分析了当前该地区野生菌类资源的开发利用状况,并结合当地实际,提出了相应的合理化建议. 相似文献
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209.
Yoshiaki Tsuzuki Masato Fujii Yasuo Mochihar Kouki Matsu Minoru Yoneda 《环境科学学报(英文版)》2010,22(6):892-897
The first social experiment program in Japan to reduce domestic wastewater pollutant discharge by “soft interventions” in households
has been conducted in the Yamato-gawa River drainage area since 2005. The Yamato-gawa River has been listed as one of the worst
water quality rivers in Japan because of the larger annual average BOD. “Hard interventions” including deployment of wastewater
treatment facilities and artificial installation of natural purification facilities in the river has been conducted in these years to improve
river water quality. At the first Yamato-gawa River social experiment program (YR-SEP) in March 2005, BOD at the monitoring point
near the river mouth decreased about 6% during the Program. Natural purification e ect along the river was evaluated in this article
with one-dimensional water quality model for the six river sections. Larger biological oxygen consumption rate, kb, was estimated in
the sections with artificially installed natural purification facilities. The e ect of “soft interventions” in households in the YR-SEP was
estimated as 25% BOD decrease in the nearest monitoring point to the river mouth, when all the households participate in the Program
and BOD discharge reduction rate with “soft interventions” in households was 40%. 相似文献
210.
Apostolos Kapranas P. Pacheco L. D. Forster J. G. Morse R. F. Luck 《Behavioral ecology and sociobiology》2008,62(6):901-912
We examined whether several facultatively gregarious encyrtid (Hymenoptera: Encyrtidae) endoparasitoids of brown soft scale,
Coccus hesperidum L., manifest precise sex allocation under field conditions. Metaphycus luteolus (Timberlake), Metaphycus angustifrons (Compere), Metaphycus stanleyi (Compere), and Microterys nietneri (Motshulsky) evince brood sex ratios that are female-biased and extremely precise (low variance in the number of sons per
host). Typically, this sex allocation pattern is attributed to extreme local mate competition (LMC) in which only one foundress
exploits a patch of hosts and mating occurs mostly between her offspring. However, such a pattern of sex allocation was not
detected for Metaphycus helvolus (Compere). Also, a large proportion of the broods in all five species contained only daughters; thus, an excess of male-only
broods was expected if unmated females (i.e., females that can produce only sons) contribute offspring before mating. All-male
broods were rare in our samples. This finding coupled with the life history characteristics of these wasps, such as the exploitation
of aggregated hosts and the long life span and mobility of males, suggest that nonlocal mating is frequent. Our empirical
work suggests that it is advantageous to allocate precise sex ratios in cases in which mating opportunities for males are
not restricted to their natal host and/or when multiple foundresses exploit large patches of hosts. Limited theoretical work
also supports this prediction but more detailed studies of this taxon’s mating structure and other life history characteristics
are necessary to understand their sex allocation decisions. 相似文献