【作者】 张树斌；

【导师】 郑征；

【作者基本信息】 中国科学院研究生院（西双版纳热带植物园） ， 生态学， 2008， 硕士

【摘要】 空心树(Hollow-bearing tree)是森林生态系统的重要组成部分,它能为树洞依赖动物提供食物、栖息地、避难所、哺育地等,在维持森林动物群落的物种多样性方面起着重要作用。本研究通过在云南哀牢山国家级自然保护区徐家坝地区建立了有代表性的空心树森林调查样地6公顷,调查分析了哀牢山中山湿性常绿阔叶林空心树的数量、径级分配、树种组成以及树洞的丰度及组成,阐述了哀牢山中山湿性常绿阔叶林空心树分配规律。分别在雨季和干季采集空心树木质残体对其呼吸速率进行了测定,并比较了木质残体呼吸速率与木质密度和含水量之间的相关关系,分析了呼吸速率对温度的敏感性,并对木质残体呼吸速率与含水量、木质密度和气温进行了多元线性回归,以确定空心树木质残体分解的影响因子和限制因子。研究结果如下:1.哀牢山中山湿性常绿阔叶林空心树密度平均为92.8±11.9株/公顷,样地间存在较大的变异。活木和枯立空心树密度和形成空心树的比例都有显著差异(P<0.05),活木和枯立木空心树密度分别为82.2±11.8株/公顷和10.7±1.1株/公顷,空心枯立木的比例(18.0±3.2%)显著高于活木(7.7±0.5)(P<0.05)。活木和枯立空心树的径级分配以20≤DBH<40 cm级别的最多(28.4%),80≤DBH<100 cm级别的最少(3.2%),随着胸径的增大,活木空心树所占比例也显著增大。枯立空心树径级分配也以20≤DBH<40 cm级别的最多(28.4%),显著高于其它几个径级的(P <0.05)。空心树物种组成物种丰富,分属于15科34种,空心树分别占科和种层次的83.3%和68.0%。空心树数量科层次上以壳斗科(Fagaceae)、山茶科(Theaceae)、樟科(Lauraceae)和木兰科(Magnoliaceae)为主,与该区中山湿性常绿阔叶林优势科相一致。空心树数量种层次上以腾冲栲(Castanopsis wattii)、木果柯(Lithocarpus xylocarpus)、硬壳柯(Lithocarpus hancei)、红花木莲(Manglietia insignis)、滇润楠(Machilus yunnanensis)、南洋木荷(Schima noronhae)和舟柄茶(Hartia sinensis)为主。2.哀牢山中山湿性常绿阔叶林中树洞分配不均匀,平均密度为140.3±19.2个/公顷。树洞分配以树干中部洞口和树干基部洞口最多,这两种类型的树洞数量都显著高于树干裂缝、侧枝中部洞口、侧枝顶部洞口和树干顶部洞口(P<0.05)。树洞洞口直径的级别分配以5≤d<15 cm级别的最多,这个级别的树洞数量显著高于其它三个级别的(P<0.05),各样地均表现为随洞口直径增大,树洞密度明显减少。3.空心树树干内层和洞内木质残体的密度显著高于树干表层的(P<0.05),而树干内层和洞内木质残体的密度之间差异不显著(P >0.05)。空心树树干表层木质残体雨季呼吸速率显著高于树干内层和洞内的(P<0.05),在干季,树干表层、树干内层和洞内木质残体呼吸速率之间差异不显著(P>0.05)。含水量和呼吸速率存在季节差异,在树干表层和洞内雨季的含水量和呼吸速率显著高于干季的(P<0.05),而在树干内层季节差异不显著(P>0.05)。空心树三个部位木质残体密度与呼吸速率在雨季显著负相关(P<0.01),三个部位的含水量和呼吸速率在雨季和干季都显著正相关(P<0.01);木质残体的温度系数(Q10)大小顺序为:洞内(2.08)>树干表层(2.01)>树干内层(1.73),树洞内部木质残体对温度响应最敏感。木质含水量、密度和气温的综合作用对三个部位的空心树木质残体呼吸速率的影响显著(P<0.001)。哀牢山干季空心树木质残体较低的含水量和全年温凉的气候条件可能成为该区中山湿性常绿阔叶林空心树木质残体分解重要的限制因子。更多还原

【Abstract】 Hollow-bearing tree is an essential component of forest ecosystems, which plays a key role in animal biodiversity of forest fauna in forest ecosystem. Many forest animals use cavities of hollow-bearing trees for nesting, resting, habitat and feeding sites. The formation of hollow-bearing tree is the result of a series of abiotic and biotic events after the wounding of trunk and branch tissue. Six representative plots (6 ha.) in Xujiaba of Ailao Mountains national nature reserve were chosen. The abundance, DBH (Diameter at Breast Height) class distribution and species composition of hollow-bearing tree, the abundance and composition of cavity were investigated. The distribution pattern of hollow-bearing tree in middle mountain moist evergreen broad-leaved forest of Ailao Mountains was analyzed. The woody debris of hollow-bearing tree was selected and its respiration rate was measured during the rainy season and the dry season in the middle mountain moist evergreen broad-leaved forest of Ailao Mountains, SW China. Furthermore, the correlations among respiration rate, wood density and moisture were analyzed and temperature sensitivity of the respiration rate was simulated. We regressed linearly respiration with wood density, moisture and air temperature in order to confirm the influencing and limiting factors of respiration of woody debris of hollow-bearing tree. The results were as following:1. The average density of hollow-bearing tree was 92.8±11.9 stems·hm-2 and there existed notable variation for different plots. The density and proportion of hollow-bearing tree differed significantly for living trees and standing dead wood (P<0.05). The density of living and standing dead hollow-bearing tree were 82.2±11.8 stems·hm-2 and 10.7±1.1 stems·hm-2 respectively. The proportion of hollow-bearing tree for standing dead wood (18.0±3.2%) was higher significantly than living trees (7.7±0.5) (P<0.05). The DBH class for the living hollow-bearing tree distributed mostly in the class (20≤DBH<40 cm) (28.4%) and least in the class (80≤DBH<100 cm) (3.2%). With the increasing of DBH, the proportion of the living hollow-bearing tree increased markedly. The DBH class for the standing dead hollow-bearing tree also distributed mostly in the class (20≤DBH<40 cm) (46.9%), which was higher significantly than other classes (P<0.05). The species composition of hollow-bearing tree was very abundant. The hollow-bearing tree belonged to 15 families and 34 tree species, which accounted for 83.3% of all families and 68.0% of tree species. The families of hollow-bearing tree distributed in Fagaceae, Theaceae, Lauraceae and Magnoliaceae that were dominating families. The species of hollow-bearing tree distributed mainly in Castanopsis wattii、Lithocarpus xylocarpus、Lithocarpus hancei、Manglietia insignis、Machilus yunnanensis、Schima noronhae and Hartia sinensis.2. The cavities distributed unevenly with their average density 140.3±19.2 hollows·hm-2. There were the most cavities for the type of Trunk middle and the type of Butt Hollow secondly. The cavities for the type of Trunk middle and the type of Butt Hollow were more significantly than the other four types (P<0.05). There was the most cavities for the entrance size class of 5≤d<15 cm, which was more than the other three classes (P<0.05). With the entrance size increasing, the density of cavities decreased dramatically.3. The density of woody debris of inner layer of trunk and hollow was higher significantly than surface layer of trunk of hollow-bearing tree (P<0.05), but the difference of density between inner layer of trunk and hollow was not significant (P >0.05). The respiration rate of surface layer of trunk during rainy season was significantly higher than that of inner layer of trunk and hollow (P<0.05), but the difference of respiration rate during dry season was not significant for three positions (P>0.05). The wood moisture and respiration rate of the surface layer, the inner layer and the hollow were higher during the rainy season than the dry season, and the difference was significant (P<0.01) for the surface layer and hollow,but not significant (P>0.05) for the inner layer. There was negative correlation between wood density and respiration rate, and the correlations for three different positions during rainy season were significant (P<0.01). There was positive correlation between wood moisture and respiration rate for the three different positions during both rainy season and dry season. The temperature coefficient (Q10) for three positions ranks as: Hollow (2.08) > Surface layer (2.01)> Inner layer (1.73), which shows wood debris of hollow was the most sensitive to temperature. The respiration rate of woody debris of hollow-bearing tree was significantly due to the integrative effect of wood moisture, density and air temperature (P<0.001). The low wood moisture during dry season and the cold climate during whole year were key limiting factors for the decomposition of woody debris of hollow-bearing tree in the middle mountain moist evergreen broad-leaved forest of Ailao Mountains, SW China.更多还原