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161.
贵州关岭县喀斯特峰丛石漠区苔藓群落生态特征 总被引:2,自引:6,他引:2
为了了解喀斯特峰丛石漠化区苔藓植物的种类和群落特征,本文选取贵州省安顺市关岭县喀斯特峰丛石漠化区的三种典型生境(裸地、人工植被和自然植被),对苔藓植物进行样地调查,并利用种间相遇几率(PIE)、生态优势度、Shaanon-Wiener信息指数(衡量生态位宽度)和Morisita-Horn指数(衡量生态位重叠)来分析该区苔藓植物群落的组成、分布规律及生态特征。结果表明:(1)该区苔藓植物共有11科17属22种,真藓科为优势科,苔藓植物群落有19个类型。(2)苔藓群落PIE值与植被覆盖度呈正比,与岩石裸露率呈反比,自然植被生境的苔藓群落PIE值高于人工植被和裸地生境,但研究区苔藓群落PIE总体偏低,反映了喀斯特峰丛地区恶劣的生境条件。(3)研究区内卷叶湿地藓群落(Hyophiletum)、直蒴卷柏藓群落(Racopietum)和皱叶牛舌藓群落(Anomodetum)有着较高的生态优势度和生态位宽度,并且与其它苔藓群落的生态位重叠值很高。表明这三种苔藓群落对不同类型的峰丛石漠化生境都有着较好的适应能力,能够很好地与其它苔藓群落互利共生。 相似文献
162.
天然气水合物分解及其生态环境效应研究进展 总被引:8,自引:2,他引:8
了解大陆/大洋边缘地区天然气水合物形成与分解及其在海底沉积物、水体及海底化学自氧生物群落中的一系列物理、化学及生物作用有助于我们在全球和区域尺度上探讨天然气水合物分解对气候变化的影响;天然气水合物在碳循环中的作用和大陆边缘流体活动与物质交换机制等问题。从水合物分解与全球变暖、贫/缺氧甲烷氧化作用、自生矿物沉淀、化学自养生物群落等方面综述了水合物的环境生态效应研究进展。天然气水合物的形成/分解及
其对海洋乃至全球环境生态变化的影响,深刻地反映了地球上岩石圈、水圈、大气圈和生物圈之间相互联系与相互作用,生物,特别是微生物对全球CH 4的平衡和自生矿物沉淀至关重要。 相似文献
163.
应用Terra和Aqua卫星的MODIS资料和三维叶分布模式,结合MODIS陆地植被覆盖产品数据,估算了6种生物群落的LAI,并与我国西北地区叶面积仪观测结果进行了对比和分析。结果表明,从两颗卫星连续8天的观测资料可以估算出LAI,反演结果的相对误差基本在±20%以内,平均相对误差为13.7%,说明该方法可以反演实际植被的LAI;根据植被类型的差异,建立了6种生物群落LAI与NDVI的指数关系,相关性较好;青藏高原东部的LAI时间变化有不一致性的特征,反映了不同生物群落的生物学特性的差异;不同季节的LAI变化在空间上有很大差异,说明本研究区域西部冷、干和高原东部相对暖、湿的复杂气候特征。 相似文献
164.
专家系统是一门新兴的计算机人工智能实用学科,它能够应用专家的知识和思维方式去解决实际问题。它主要由知识库和推理机组成。HNDPES系统是在总结河南主要矿产成矿规律的基础上建造的矿床预测专家系统。在河南省富铝土矿成矿预测中取得了良好的效果。 相似文献
165.
N.V. Aladin A.A. Filippov I.S. Plotnikov M.I. Orlova W.D. Williams 《International Journal of Salt Lake Research》1998,7(4):301-343
The construction of a dam between the Small and Large Aral Sea in 1993 has had an effect on biological communities. From field and laboratory investigations and analysis of the literature, the structure and function of the main plant and animal communities in the northern (Small) Aral Sea are described and discussed, first, for the period before 1985, and, second, between 1985 and 1994. A prognosis for future changes is provided. 相似文献
166.
PATRICIA NELSON LIMERICK 《Geographical review》1998,88(4):483-491
ABSTRACT. Adopting the persona of the nonacademic, J. B. Jackson was, nonetheless, a major influence on academic scholarship. Expertly and deftly, he played on his understanding of scholarly convention, pushing the boundaries of “legitimate” generalization and assertion. Careful observation of his style reveals eight strategies for testing, mocking, and challenging habits of mind that can unnecessarily constrict scholarly inquiry. From daring in the drawing of conclusions to the wily use of the pronoun “we,” from a refusal to defer to middle-class values to the baiting of environmentalists, Jackson at once had a good time and called much of academic propriety into question. An examination of his “game plan” gives scholars a chance to examine their own habitual practices. 相似文献
167.
The notion of ‘eco‐civic regionalisation’ has been applied recently to New South Wales by Brunckhorst, Coop and Reeve (2004) in order to identify the appropriate administrative boundaries for ‘socio‐civic’ regions and ‘biophysical’ regions. On the basis of this analysis, they recommended inter alia that 49 future non‐metropolitan ‘local government areas’ be established. This proposal was adopted with alacrity by advocates of the NSW government's program of compulsory council amalgamation, including official ‘Facilitators’ appointed by the State government to draft formal consolidation proposals. This paper disputes the applicability of ‘eco‐civic regionalisation’ as the foundation for local government boundaries in Australia. 相似文献
168.
Stefano Schiaparelli Michela Castellano Paolo Povero Gianfranco Sartoni & Riccardo Cattaneo-Vietti 《Marine Ecology》2007,28(3):341-353
In this contribution we document an anomalous mucilage growth which occurred in June 2003 along the rocky cliffs of the Portofino Promontory (Ligurian Sea, NW Mediterranean Sea), and we describe its dynamics and its negative effects on many benthic taxa. The zooxanthellate scleractinian Cladocora caespitosa underwent ‘bleaching’ and about 40% of biomass of the erect algae was detached by mucilage ‘lianas’ created and strengthened by bottom currents. The 2003 event differed from any other previously occurred in the northern Tyrrhenian Sea, in that the mucilage aggregates were formed by the free‐living form of the Phaeophyceae Acinetospora crinita (Harvey) Kornmann, a not usually dominant species in mucilage aggregates from the north Tyrrhenian Sea. The damage suffered by the benthic organisms living in this area was curtailed by a severe storm, occurred in July, which removed the mucilage to deeper depths, preventing irreversible damages. Only slow growing, perennant organisms, such as corallinales or scleractinians, were seriously affected, but a survey carried out 1 year later, in June 2004, allowed to appreciate a complete recovery of those organisms. This anomalous mucilage event occurred in coincidence of the 2003 European heatwave, and the anomalous temperature increase of seawater has to be regarded as the major contributing event that led to the mucilage outbreak. 相似文献
169.
170.