森林植被的自然火干扰

森林植被的自然火干扰邱扬（山西大学黄土高原研究所,太原０３０００６）ＮａｔｕｒａｌＦｉｒｅＤｉｓｔｕｒｂａｎｃｅｏｆＦｏｒｅｓｔＶｅｇｅｔａｔｉｏｎ．ＱｉｕＹａｎｇ（ＩｎｓｔｉｔｕｔｅｏｆＬｏｅｓＰｌａｔｅａｕ,ＳｈａｎｘｉＵｎｉｖｅｒｓｉｔｙ,...     

RS和GIS在植被生态学中的应用及其前景

近年来,随着遥感和计算机软、硬件技术的发展与完善,利用遥感数据所进行的生态学研究已经深入到生态学的许多领域,取得了丰富的研究成果,并将继续在区域和全球尺度上的生态学研究中起着极为重要的作用。利用遥感所进行的生态学研究主要是基于植物的反射光谱特征来实现的。植物的反射光谱曲线具有显著特征。在可见光谱段,绿色植物的平均光谱反射率低于干土,而高于或接近于水体。在近红外谱段,植物的平均光谱反射率比土壤或水体高,以水体为最低。在中红外谱段,植物的平均光谱反射率比水体略高（或相近）,但明显高于干土。在０．３５…     

芦芽山自然保护区旅游开发与植被环境的关系Ⅰ.植被环境质量分析

采用敏感水平、群落景观重要值、物种多样性信息指数等一系列评价指标 ,探讨了芦芽山自然保护区旅游开发与植被生态环境的关系。通过一系列评价指标分析 ,结果表明 :保护站～冰口凹段 ,敏感水平不断增大 ,景观重要值不断减小 ;冰口凹到 2 4 2 0 m段 ,敏感水平开始逐步减小 ,景观重要值则不断上升 ;2 4 2 0～ 2 5 80 m段 ,敏感水平又开始逐步回升 ,景观重要值则又迅速下降。物种多样性信息指数随着海拔的不断上升 ,呈一条波动且渐趋上升的曲线。但阴生种比值不能很好地反映生态环境质量的优劣。这些指标的变化趋势和其相互关系相吻合 ,且与植被现状大体一致 ,反映了整个自然保护区植物群落的旅游价值及其生态环境质量。同时 ,距游径的水平距离对植物群落及其景观特征的影响也较为明显。研究结果较好地反映了芦芽山旅游开发现状 ,与实际状况大致吻合 ,说明这一方法是可行的     

Vegetation classification,mapping, and monitoring at Voyageurs National Park,Minnesota: An application of the U.S. National Vegetation Classification

Question: How can the U.S. National Vegetation Classification (USNVC) serve as an effective tool for classifying and mapping vegetation, and inform assessments and monitoring? Location: Voyageurs National Park, northern Minnesota, U.S.A and environs. The park contains 54 243 ha of terrestrial habitat in the sub-boreal region of North America. Methods: We classified and mapped the natural vegetation using the USNVC, with ‘alliance’and ‘association’as base units. We compiled 259 classification plots and 1251 accuracy assessment test plots. Both plot and type ordinations were used to analyse vegetation and environmental patterns. Color infrared aerial photography (1:15840 scale) was used for mapping. Polygons were manually drawn, then transferred into digital form. Classification and mapping products are stored in publicly available databases. Past fire and logging events were used to assess distribution of forest types. Results and Discussion: Ordination and cluster analyses confirmed 49 associations and 42 alliances, with three associations ranked as globally vulnerable to extirpation. Ordination provided a useful summary of vegetation and ecological gradients. Overall map accuracy was 82.4%. Pinus banksiana - Picea mariana forests were less frequent in areas unburned since the 1930s. Conclusion: The USNVC provides a consistent ecological tool for summarizing and mapping vegetation. The products provide a baseline for assessing forests and wetlands, including fire management. The standardized classification and map units provide local to continental perspectives on park resources through linkages to state, provincial, and national classifications in the U.S. and Canada, and to NatureServe's Ecological Systems classification.     

植被科学与多元向量分析

提出植被分析的新数学方法－－多元向量分析法。植被群落是由多种植物组成的。植被状态可以用多维物种空间的点,或连接空间点和原点的多元向量来,向量同时具有量值和方向。向量的量值（长度）表示植被所含物质,能量,信息的总量,而方向表示这个总量在各物种间的分配。在射影空间里,同一射线上的点表示成分相同的植被（或代表相同植被的点组成射线）。用余弦表示的向量方向是植被数量化,进而施行植被成分分析的关键。向量分析既可以用来进行植被分类,也可以用于植被动态监测。     

温、湿度对粘虫蛾飞行能源物质利用的影响

系统研究了不同温、湿度对粘虫蛾飞行能源物质消耗的影响,结果表明,温、湿度对成虫飞行能源物质消耗有显著影响,在适宜的温、湿度下飞行时,粘虫蛾主要飞行能源物质（甘油三酯和糖原）消耗最少,其飞行单位距离所需的甘油三酯也最少,即能源利用效率最高,随着温,湿度从适宜到不适宜,甘油三酯消耗有逐渐增多的趋势,但温,湿度对成虫飞行能源物质消耗会因蛾龄及性别的不同而异,在所测试的几种温,湿度下（高温35℃除外）,5日龄成虫在飞行中消耗的甘油三酯最多,低龄和高龄时消耗均较少,高温下飞行时,雄蛾比雌蛾消耗的能源物质多,而在高温或低湿条件下,雌蛾比雄蛾消耗的多,进一步对影响成虫飞行能源物质消耗的海藻糖酶活力及呼吸强度研究表明,温、湿度对海藻糖酶活性有明显影响,在适宜的温,湿度下,酶的活性高,反之,酶的活性降低,其中高温对酶活性的抑制作用比低温明显,但高湿和低湿对酶活性的抑制作用基本一致,成虫呼吸强度随温度的升降而升降,飞行初期成虫呼吸强度急剧增加,但0.5h后开始下降并维持在一个较稳定的水平,根据所获结果对温、湿度与粘虫蛾飞行能源物质消耗之间的内在联系进行了讨论.     

江苏盐城黑嘴鸥的繁殖栖息地选择

对江苏盐城黑嘴鸥繁殖期觅食地和营巢地及其主要特征进行了调查,黑嘴鸥繁殖觅食地有盐田,碱蓬滩,草滩,水产品养殖塘,农田,泥质滩涂及河口港汊7种类型,生境选择的结果表明黑嘴鸥对碱蓬滩涂和泥质滩涂都有正选择性,对农田和河口港汊具有负选择性,繁殖前期对养殖塘具有正选择性,不同繁殖时期黑嘴鸥对碱蓬滩和养殖塘的利用情况变化最明显,两年中,黑嘴鸥对河口港汊的利用情况稳定,黑嘴鸥营巢地有獐毛滩,碱蓬滩和大米草滩3种类型,其中碱蓬滩是其主要营巢栖息地,对巢址选择因子的分析的结果表明：影响黑嘴鸥巢址选择的因子主要有4类,依次为：植被盖度和群集度,人为活动干扰强度,底栖生物量及距水源距离,其贡献率分别为26．23％,20．55％,14．82％,14．02％。     

Vegetation structure and species coexistence

“Vegetation Structure and Species Co-existence” was the topic of a symposium organized in 1992, in Tartu, Estonia. The symposium was dedicated to the memory of Professor Teodor Lippmaa (1892–1943), who made important contributions, especially to the concept of synusia in community ecology. Current views on relation between vegetation structure and species co-existence vary. This variation is partly due to the traditional opposite views of plant community structure (the individualistic and organismic concept); these views refer both to the strength and role of biotic interactions within a community, and to the community structure.