北京山区落叶阔叶林中核桃楸在生长中期的树干液流研究

北京山区落叶叶林优势种－－核桃楸在生长中期没有水分亏缺的条件下,树干的液流速率在很大程度上为微气候因子所决定,特别是大气相对湿度、温度和太阳辐射强度等。核桃楸树干液流速率的日进程和大气相对湿度、温度的日进程具有很好的生态学同步性。在一天中树干液流速率会出现数次波动,有多个峰值,最高峰一般出现在１５：００左右,可达到１６００ｇ／ｈ。在夜晚时核桃楸树干液流速率非常低,一般在５０ｇ／ｈ以下,但总是存在,     

武夷山黄山松群落能量的研究

在生物量,生产力研究的基础上,通过干重热值测定,对黄山松（Ｐｉｎｕｓｔａｉｗａｎｅｎｓｉｓ）群落的能量现存量,能量净固定量及太阳能转化效率进行分析讨论,测定结果表明,（１）黄山松群各组分样品的干重热值具有一定的差异,树皮的干重热值最高,为２２．１４ｋＪ／ｇ,枯根的干重热最低,为１６．２７ｋＪ／ｇ。（２）黄山松群落的能量现存量为３７９８３２．３ｋＪ／ｍ＾２,其中地上部分为２７５４８８．０ｋＪ／ｍ＾２     

秦岭天然锐齿栎林群落区系研究

锐齿栎林是秦岭林区的主要森林类型之一。通过对秦岭天然锐齿栎林群落的野外调查,报道了组成该群落的植物种类１８３种,隶属于６０科,１３１属,并在此基础上对该群落区系特点作了较为详细的分析。分析表明：１．该群落区系具有明显的温带性质。２．该群落区系是奠基在秦岭古老植物区系的基础上,通过种间竞争、群落演替形成的。３．锐齿栎本身不是一个古老的类群,其出现的时间不会早于上新世。     

长白山红松阔叶林主要树种高度生态位的研究

森林生态系统内主要乔木的高度生态位反映了不同树种在各个高度资源单位内资源利用的互补情况,同时也是表征森林生态系统演替的趋势及其森林循环过程主要特征之一．生物学特性和生态学特性接近的树种的高度生态位重叠较大,反之则较小．在Ｇａｐ内,色木槭和扭筋槭的高度生态位重叠最大,而青楷槭和千金榆、花楷槭和水曲柳、青楷槭和裂叶榆的高度生态位重叠较小;在非Ｇａｐ生态系统内,青楷槭和白牛槭的高度生态位重叠最大,青楷槭和裂叶榆、青楷槭和千金榆、花楷槭和水曲柳的高度生态位重叠较小．红松和阔叶树之间的高度生态位分离较大,利用资源的方式和能力差异较大,它们之间可以在不同空间的资源利用上达到互补,种间竞争较弱,从而能够保持红松和阔叶树之间长期而稳定的共存．但Ｇａｐ内红松和阔叶树的高度生态位重叠均大于非Ｇａｐ生态系统,可见Ｇａｐ的存在加大了红松和阔叶树之间的种间竞争,减小了红松和阔叶树之间的资源互补利用的能力．Ｇａｐ削弱了个体生态位重叠值较大的树种间的种间竞争,增强了个体生态位重叠值较小的树种间的种间竞争     

Birch family and environmental conditions affect endophytic fungi in leaves

We investigated whether variation in foliar endophyte frequency among mountain birch trees from different maternal families was due in part to genetic differences among trees. The effect of different environmental conditions on the susceptibility of these mountain birch families to foliar endophytes was tested. The 3-year study was conducted in two tree gardens (altitudinal difference 180 m) with ten families of mountain birch. The frequency of the commonest endophytic fungus in mountain birch leaves, Fusicladium sp., was significantly affected by mountain birch family, with the ranking of families relative to Fusicladium sp. frequency being consistent from environment to environment. Variation in the frequency of Melanconium sp. was difficult to interpret because of significant family × garden × year interaction. Fusicladium sp. and Melanconium sp. endophytes were most frequent in different tree individuals, families and gardens. We conclude that mountain birch trees show heritable variation in their foliar endophyte frequency, and thus one of the conditions necessary for foliar endophytes of mountain birch trees to be able to affect the evolution of their host plant is fulfilled. However, the effect of mountain birch family on the frequency of endophytic fungi varies depending on the endophytic genera in question and partially also on environmental conditions. Received: 28 March 1998 / Accepted: 14 October 1998     

The Geographical Distribution and Floristic Composition of the Orchids in the Gongga Mountain Region,Sichuan

The Gongga Mountain Region, located on the eastern fringe of QinghaiXizang Plateau and at the north-eastern end of Hengduan Mountains, is one of the well-known large mountain areas in Sichuan Province. There are forty five high peaks with the elavation of 6000 m or over in the area, among which the Gongga Mountain is the highest one, with its summit being at the altitude of 7556 m, whereas the Dadu River Valley in the eastern part of the area is only 1150 m above sea level; The relative height in the region is thus about 6400 m. As we know so far the orchids in Gongga Mountain Region comprise 34 genera and 75 species with 1 variety, of which 12 species are epiphytes, 59 species with 1 variety terrestrials and 4 species saprophytes (Table 1.). I. The geographical distribution in the Gongga Mountain Region. The vertical distribution of the orchids in the area. Eastern flank: There are 39 species with I variety of orchids at 1150-2300 (-2400) m alt. in the subtropical evergreen broadleaf forest zone, of which 12 species, such as Bulbophyllum andersonii, Dendrobium hancockii, Otochilus porrecta, etc., are epiphytic (including a semiepiphyte, Pleione bulbocodioides), 25 species with 1 variety, such as Bletilla formosana, Calanthe davidii, Cypripedium henryi, etc., are terrestrial, and 2 species are saprophytic (i.e. Gastrodia elata and Neottia listeroides), the upper limit of the real epiphytic orchids is 1800 m alt. At the altitude 2300(-2400)-3600 (-3800) m, in the coniferous forest zone, found are 23 species, including 20 terrestrial species with 1 variety, such as Amitostigma gonggashanicum, Calanthe fimbriata, Coeloglossum viride, etc., 2 saprophytic species (Neottia acuminata and Risleya atropurpurea) and one semiepiphytic species. There are only 2 terrestrial species (i.e. Cypripedium tibeticum and Orchis chusua) at 3600(-3800)-4000m alt., in alpine shrub zone, the upper limit of the terrestrial orchids being 4000 m alt. At 4000-4400 m alt., in alpine meadow zone no orchids have so far been found. Western flank: There are 14 species of orchids, such as Habenaria limprichtii, Hemipilia flabellata, Satyrium ciliatum, etc., at 2300-2800 m alt., in the river valley shrub zone, and they all belong to the terrestrial orchids. At the altitude of 28003800m, in the coniferous forest zone found are 19 species of orchids, among which 18 species are terrestrial (such as Amitostigma monanthum, Cephalanthera longifolia, Peristylus coeloceras, etc.) and one is saprophytic. There are only 4 species of terrestrial orchids (i.e. Cypripedium tibeticum, Gymnadenia orchidis, Orchis chusua and O. diantha) at 3800-4800 m alt., in the alpine shrub-meadow zone, the upper limit of vertical distribution of terrestrial orchids being 4400 m alt. Twelve species here are common to the eastern flank. II. The floristic composition of orchids in Gongga Mountain Region. 1. Twenty three species, belonging to 13 genera, are widespread in Whole EastAsian Region. 2. Eight species, belonging to 8 genera, are the elements of the Sino-Japanese Subregion. 3. Forty one species with 1 variety, belonging to 24 genera, are the elements of the Sino-Himalayan Subregion, more than five times the elements of the Sino-Japanese Subregion. 4. The floristic features of the orchids in the area. (1) The floristic elements are mainly temperate and subtropical ones. (2) The life form is mostly terrestrial. (3) The species endemic to China are prolific (35 species with 1 variety, belonging to 18 genera, are endemic to China, and 26 species with 1 variety are distributed in south-western China and its adjacent region; Amitostigma gonggashanicum is endemic to the area). The floristic composition of orchids in the area is characterized by the dominance of terrestrial species and temperate and subtropical East-Asian elements, though with a few Indo-African tropical elements (such as genus Satyrium (1 species) ). In conclusion, it may be considered that the species of orchids are abundant and floristic elements are comparatively complex in the Gongga Mountain Region.     

A Preliminary Study on the Relationship Between the Pollen Percentages in Forest Surface Samples and Surrounding Vegetation on west Mountain of Kunming,Yuunan

Pollen analysis of five moss patches collected from the forest floor on West Mountain of Kunming (N 24˚57', E 102˚37') provided informations about the quantitative relations between pollen content and coverage of principal plant taxa. Vegetational data with coverage are estimated from each sampling site within the range of 30 m. Trees were calculated in percentage of the total arboreal, herbs and ferns are respectively computed as percentages of the latter two sorts. A preliminary R-value was estimated. According to the difference of R-values, the pollen types could be divided into two groups: 1. R> 1, means overreprsented the type containing Pinus, Alnus, Cyclobalanopsis, Artemisia, and ferns; 2, R <1, means under-represented the type containing Keteleeria and Michelia. But the differences in the values for RPinus, RAlnus etc. in five samples reflected the significant differences in pollen productivity or pollen dispersal efficiency of Pinus, Alnus, etc. Therefore, the ratio of R-value was equal. Five genera have been calculated. The relative R-values for five tree species were: Ra:Rb:Rc:Rd:Re=l:21:5:25:30 (a. Keteteeria; b. Cyclobalanopsis; c. Castanopsis; d. Pinus and e. Alnus). These computations are only a rough estimate because the samples are too few.     

岷山山系大熊猫自然保护区2003年生物多样性监测

岷山山系是全球生物多样性保护的热点地区之一,有着全世界最大的大熊猫种群和面积最大的大熊猫栖息地。到2003年底,在该地区已建立了20个以保护大熊猫为主的自然保护区。从2003年开始,岷山17个大熊猫自然保护区实施了野外大熊猫及其栖息地监测。通过监测,了解了岷山自然保护区野生动物分布状况、人为活动对自然保护区的干扰情况,以及自然保护区周边社区经济情况,为自然保护区管理决策提供了依据。同时,通过监测活动还提高了自然保护区工作人员的业务水平。建议今后将自然保护区监测工作纳入自然保护区日常工作中。     

贵州佛顶山国家级自然保护区东方蜜蜂群体遗传分析

为探究贵州佛顶山国家级自然保护区东方蜜蜂Apis cerana的群体遗传现状和生态廊道效应,基于15个微卫星遗传标记对该保护区内168群东方蜜蜂开展群体遗传分析,并与梵净山、雷公山国家级自然保护区的东方蜜蜂进行比较分析。结果显示佛顶山保护区东方蜜蜂的平均期望杂合度为0.6948±0.0374、等位基因数为10.07±5.55、香农指数为1.5345±0.5060、多态信息含量为0.6552±0.1608,有效种群大小为825.3,与梵净山、雷公山保护区的东方蜜蜂没有遗传分化。佛顶山保护区东方蜜蜂遗传多样性处于全国较高水平,并与梵净山、雷公山东方蜜蜂存在明显的基因交流。研究结果揭示了佛顶山保护区维持蜜蜂遗传多样性的作用和生态廊道作用,揭示了距离110 km内多个保护区能够保证东方蜜蜂畅通的基因交流、避免近交衰退。同时,研究明确了多个保护区在蜜蜂遗传资源保护上的作用,为东方蜜蜂资源保护提供了积极的科学依据。     

Alpine community recruitment potential is determined by habitat attributes in the alpine ecosystems of the Himalaya‐Hengduan Mountains,SW China

The fragility and sensitivity to climate change of alpine ecosystems make it difficult to maintain the stability of their plant communities. Thus, it is important to determine which plant propagules are stored in the soils in order to understand community recruitment potential, especially under different environmental conditions. Based on a soil seed germination and seedling cultivation experiment, we aimed to identify differences in the soil seed attributes between three typical habitat types in the alpine subnival ecosystems of the Himalaya‐Hengduan Mountains and hence to predict the community recruitment potential of each of these different communities. We found that the seed assemblages in the soils differed between habitats. The most abundant taxa were from the genera Saxifraga, Kobresia, Arenaria, Polygonum, Draba, and Viola, while the taxa with lowest abundance were Apiaceae, Campanulaceae, Circaea, Crassulaceae, and Gentiana. Different habitats exhibited variable soil seed richness, diversity, and density. However, the patterns differed between study sites. Specifically, at Baima (BM) and Shika (SK) snow mountains, soil seed richness, diversity, and density were generally highest in grassland, followed by rock bed and bare ground. In contrast, on Jiaozi (JZ) snow mountain, the rock bed supported the highest soil seed richness and density, followed by grassland and bare ground. These results suggest that the attributes of habitats and communities can both affect the accumulation of soil seeds. Bare ground supports the lowest seed diversity and density but also harbors the most empty niches. We, therefore, predict that, once the thermal conditions become suitable as a result of global warming, this habitat has the potential to see greater changes than grassland and rock bed in terms of community recruitment.