清江隔河岩坝区杉木—南酸枣林的群落学特征

杉木－南酸枣林是清江隔河岩坝区的一种典型次生林。野外调查结果表明，该群落的组成与结构比较复杂，群落的区系组成凤落叶阔叶树种主主，显示出由中亚热带向北亚热带过渡性植被地段次生群落的特征。该群落的物种多样性在同地区的次生林类型中处于较高水平，表明群落以前受到过中度干扰。目前的恢复状况较好，群落的演替趋势是常绿阔叶落叶阔叶混交林。     

闽北次生常绿阔叶林主要树种空间分布格局及其应用研究

应用聚集度指标、Ｉｗａｏ 方程和Ｔａｙｌｏｒ 幂法则模型等测定方法,研究了闽北次生常绿阔叶林９ 个主要树种的空间分布格局．研究结果表明,闽北次生常绿阔叶林９ 个主要树种的空间分布呈聚集分布,分布的基本成份为个体群,个体群分布聚集．根据Ｉｗａｏ 的Ｍ＊ 与ｘ 的回归方程,计算了９ 个树种在不同密度和允许误差下的理论抽样数．     

广东南部电白小良试验站4种森林群落结构的对比研究

通过对小良试验站不同类型、不同林龄的３种人工林群落（群落Ｂ：桉林；群落Ｃ：松桉混交林；群落Ｄ：阔叶混交林）与当地自然次生热带季雨林（乡土林）相比较，从群落结构的角度探讨人工恢复热带森林的可行性．结果表明：从桉林到松桉混交林到阔叶混交林，３种人工林群落的组成结构和空间结构向着复杂性和稳定性方向发展，并逐渐向地带性自然次生林方向演替；群落的相似性研究也表明，阔叶混交林是３种人工林中与乡土林最为相似．因此，对于极度退化的热带丘陵台地区，在一定工程和生物措施基础上，用先锋绿化树种造林成功后，及时用多层多种的阔叶混交林改造原有先锋林，可以加速人工林向地带性植被类型演替．     

清江隔河岩坝区杉木-南酸枣林的群落学特征

杉木—南酸枣林是清江隔河岩坝区的一种典型次生林。野外调查结果表明 ,该群落的组成与结构比较复杂 ,群落的区系组成以落叶阔叶树种为主 ,显示出由中亚热带向北亚热带过渡性植被地段次生群落的特征。该群落的物种多样性在同地区的次生林类型中处于较高水平 ,表明群落以前受到过中度干扰 ,目前的恢复状况较好 ,群落的演替趋势是常绿阔叶落叶阔叶混交林     

自然条件下植物叶片CO2同化率昼夜变化的生理生态特性

本文利用二氧化碳分析仪及开放式叶室，分别于旱、温季节在野外观测１３种乔木树种的叶片ＣＯ２同化速率的全天变化，分析各种植物白天净光合速率曲线类型的特点和夜间呼吸与气温的回归关系．结果：７月份植物白天光合时间相对较长，中午，植物光合曲线的午休现象表现不一，曲线特征取决于种的生物特性及环境因子．在气温较高的范围内（２５～３０℃）夜间阔叶树种的呼吸与气温呈负相关，但在１月份却不明显，针叶树种的夜间呼吸无论在高温、潮湿的７月份还是低温、干旱的１月份都不与温度呈现线性关系．     

亚热带6种针叶和阔叶树种凋落叶分解比较

针叶和阔叶树种分别代表了不同的生活型,其凋落叶片具有不同的分解速率.应用分解网袋法,在中国亚热带地区,选取了具有代表性的3种针叶树种(马尾松Pinus massoniana、水杉Metasequoia glyptostroboides和杉木Cunninghamia lanceolata)和3种阔叶树种(木荷Schima superb、乐昌含笑Michelis chapensis和青冈Cyclobalanopsisgtauca)的凋落叶,放置于样地杭州千岛湖的林地中,经过1 a的分解实验,分析不同类型树种凋落叶的分解特征.6种树种凋落叶质量损失过程基本符合Olson指数模型,其中,3种针叶树种(马尾松、水杉和杉木)凋落叶的分解系数k值(分别为0.51、0.30和0.44),明显小于3种阔叶树种(木荷、乐昌含笑和青冈)凋落叶的分解系数k值(分别为0.55、1.12和0.66);同时,针叶树种(马尾松、水杉和杉木)凋落叶分解50%和95%所需时间(分别为1.36、2.31、1.78 a和5.87、9.99、7.68 a),大于阔叶树种(木荷、乐昌含笑和青冈)凋落叶的分解时间(分别为1.26、0.62、1.05 a和5.45、2.68、4.54a).多元回归分析表明,凋落物分解系数与初始钾元素含量显著相关(P<0.05).一元线性回归分析表明,凋落物的分解系数与初始钾元素和初始木质素含量均具有显著性差异(P<0.05).亚热带地区针、阔叶树种凋落叶分解的差异与自身质量密切相关,其中初始木质素与钾元素含量是控制凋落物分解的主要因素.图2表2参23     

增温对南亚热带混交林4个树种养分含量及化学计量的影响

为了解南亚热带针阔叶混交林不同树种的养分元素含量及其计量比对增温的响应情况,基于鼎湖山森林生态系统定位站的模拟增温研究平台,选取混交林中红枝蒲桃(Syzygium rehderianum)、红锥(Castanopsis hystrix)、马尾松(Pinus massoniana)和木荷(Schima superba)4个树种为研究对象,采用沿海拔梯度垂直移位模拟增温的方法,研究了4个树种叶、枝和根中主要元素含量及计量比对增温的响应情况。结果显示,增温降低了各树种各器官的C和N含量,升高了P含量。增温条件下,各树种C含量变化幅度不大,叶的N和P含量大于枝和根,不同树种对增温的响应有所差异,红锥和木荷的C、N和P含量对增温的响应大于红枝蒲桃。增温显著降低了各树种各器官的C/P和N/P,各树种在化学计量比上对增温的响应表现为红锥木荷马尾松红枝蒲桃。增温升高了各树种叶的Ca含量,其他养分在不同器官没有表现出一致的规律。研究结果揭示了南亚热带针阔叶混交林主要树种养分含量及化学计量学特征对增温的响应特征,发现增温对南亚热带主要乡土树种的影响存在一定的种间差异性,这种差异可能会影响不同树种生长,进而影响森林群落结构和功能。     

珠江三角洲四种森林类型土壤CO_2通量特征研究

采用开路式土壤CO2通量测量系统Li-8100＆Li-8150对珠江三角洲地区尾叶桉（Eucalyptus urophylla）人工林、乡土树种恢复林、针阔叶混交林和常绿阔叶林4种林型的土壤CO2通量进行了观测。结果表明：4种森林类型年均土壤CO2通量为尾叶桉人工林（3.35μmol.m-2.s-1）〉针阔叶混交林（2.66μmol.m-2.s-1）〉乡土树种恢复林（2.09μmol.m-2.s-1）〉常绿阔叶林（1.86μmol.m-2.s-1）;旱季土壤CO2通量明显小于雨季。前3种森林类型凋落物呼吸处理表明,旱季对照组土壤CO2通量均小于相应的去除凋落物组、雨季则相反,全年的对比结果显示,3种森林类型的凋落物呼吸贡献分别达到1.3%、7.1%和10.8%。土壤CO2通量与10 cm土壤温度呈显著指数相关,且土壤CO2通量温度敏感指数表现为针阔叶混交林Q10最大（3.49）,尾叶桉人工林Q10最小（1.95）。     

珠江三角洲四种森林类型土壤CO2通量特征研究

采用开路式土壤CO2通量测量系统Li-8100&Li-8150对珠江三角洲地区尾叶桉(Eucalyptus urophylla)人工林、乡土树种恢复林、针阔叶混交林和常绿阔叶林4种林型的土壤CO2通量进行了观测。结果表明:4种森林类型年均土壤CO2通量为尾叶桉人工林(3.35μmol.m-2.s-1)>针阔叶混交林(2.66μmol.m-2.s-1)>乡土树种恢复林(2.09μmol.m-2.s-1)>常绿阔叶林(1.86μmol.m-2.s-1);旱季土壤CO2通量明显小于雨季。前3种森林类型凋落物呼吸处理表明,旱季对照组土壤CO2通量均小于相应的去除凋落物组、雨季则相反,全年的对比结果显示,3种森林类型的凋落物呼吸贡献分别达到1.3%、7.1%和10.8%。土壤CO2通量与10 cm土壤温度呈显著指数相关,且土壤CO2通量温度敏感指数表现为针阔叶混交林Q10最大(3.49),尾叶桉人工林Q10最小(1.95)。     

8种乡土树种在铁矿废弃地的定植与生长

应用生态系统演替原理,选取青冈(Cyclobalanopsis glauca)、苦槠(Castanopsis sclerophylla)、白栎(Quercus fabri)、麻栎(Quercus acutissima)、小叶栎(Quercus chenii)、榔榆(Ulmus parvifolia)、紫楠(Phoebe sheareri)和薄叶润楠(Machilus leptophylla)8种乡土树种在安徽省马鞍山市南山铁矿排土场进行定植试验.定植后3 a小叶栎高度达(194.89±2.71) cm(平均值±标准误,下同),比移栽时增加119.89 cm,平均年增高39.96 cm,高度最小的紫楠也达(72.67±2.91) cm,比移栽时增加了62.67 cm,平均年增高20.89 cm;地径最大的榔榆已达(3.87±0.11) cm,最小的紫楠也达(1.27±0.15) cm,说明在人工管理条件下,这些植物生长良好.观测结果表明,落叶阔叶树种比常绿阔叶树种定植成活率高,株高和地径增长速度也较快,是该地自然群落恢复的重要候选树种.     

Tree species diversity and its relationship to stand parameters and geomorphology features in the eastern Black Sea region forests of Turkey

We studied the effects of stand parameters (crown closure, basal area, stand volume, age, mean stand diameter number of trees, and heterogeneity index) and geomorphology features (elevation, aspect and slope) on tree species diversity in an example of untreated natural mixed forest stands in the eastern Black Sea region of Turkey. Tree species diversity and basal area heterogeneity in forest ecosystems are quantified using the Shannon-Weaver and Simpson indices. The relationship between tree species diversity basal area heterogeneity stand parameters and geomorphology features are examined using regression analysis. Our work revealed that the relationship between tree species diversity and stand parameters is loose with a correlation coefficient between 0.02 and 0.70. The correlation of basal area heterogeneity with stand parameters fluctuated between 0.004 and 0.77 (R2). According to our results, stands with higher tree species diversity are characterised by higher mean stand diameter number of diameter classes, basal area and lower homogeneity index value. Considering the effect of geomorphology features on tree species or basal area heterogeneity we found that all investigated relationships are loose with R < or = 0.24. A significant correlation was detected only between tree species diversity and aspect. Future work is required to verify the detected trends in behaviour of tree species diversity if it is to estimate from the usual forest stand parameters and topography characteristics.     

Interactions among Frugivores and Fleshy Fruit Trees in a Philippine Submontane Rainforest

Abstract: We assessed the potential effect of frugivore extinctions on forest regeneration in the North Negros Forest Reserve, a forest fragment that is one of the last remaining wet tropical rainforest ecosystems in the biogeographic region of the central Philippine Islands. We evaluated foraging observations of 19 species of birds, fruit bats, and other mammals in three successional habitats and identified tree species that are potentially at risk because their seeds are dispersed by frugivores that are seriously endangered. The relative abundance of zoochorous trees in this forest community was exceptionally high (80%), suggesting that the process of forest regeneration will change drastically if endangered frugivores are hunted to extinction. We grouped 45 tree species as early-, mid-, or late-successional species based on their population structure and we demonstrated that early-successional tree species were visited by a wide spectrum of frugivores, whereas mid- and late-successional species were visited mostly by hornbills (Bucerotidae) and fruit pigeons (Columbidae). Late-successional tree species were most specialized with respect to dispersers and could therefore be susceptible to extinction. We recommend tree species that could be useful for assisted natural regeneration projects in the reserve because they are visited by a variety of frugivores. Of those, we recommend early-successional trees for open-field plantations and mid-successional tree species for enrichment plantings.     

Patterns of animal diversity in different forms of tree cover in agricultural landscapes.

As tropical regions are converted to agriculture, conservation of biodiversity will depend not only on the maintenance of protected forest areas, but also on the scope for conservation within the agricultural matrix in which they are embedded. Tree cover typically retained in agricultural landscapes in the neotropics may provide resources and habitats for animals, but little is known about the extent to which it contributes to conservation of animal species. Here, we explore the animal diversity associated with different forms of tree cover for birds, bats, butterflies, and dung beetles in a pastoral landscape in Nicaragua. We measured species richness and abundance of these four animal taxa in riparian and secondary forest, forest fallows, live fences, and pastures with high and low tree cover. We recorded over 20,000 individuals of 189 species including 14 endangered bird species. Mean abundance and species richness of birds and bats, but not dung beetles or butterflies, were significantly different among forms of tree cover. Species richness of bats and birds was positively correlated with tree species richness. While the greatest numbers of bird species were associated with riparian and secondary forest, forest fallows, and pastures with >15% tree cover, the greatest numbers of bat species were found in live fences and riparian forest. Species assemblages of all animal taxa were different among tree cover types, so that maintaining a diversity of forms of tree cover led to conservation of more animal species in the landscape as a whole. Overall, the findings indicate that retaining tree cover within agricultural landscapes can help conserve animal diversity, but that conservation efforts need to target forms of tree cover that conserve the taxa that are of interest locally. Preventing the degradation of remaining forest fragments is a priority, but encouraging farmers to maintain tree cover in pastures and along boundaries may also make an important contribution to animal conservation.     

滇西北香格里拉森林4个建群种的含碳率

森林群落的生物量及其组成树种的含碳率是研究森林植被碳储量2个关键因子,对其测定可为估算区域和全国森林生态系统碳储量的提供依据。采用重铬酸钾容量法对滇西北香格里拉县4主要树种的含碳率进行了测定,并对不同树种不同林龄不同器官的含碳率进行分析。结果表明：4树种中,云南松Pinus yunnanensis的林分平均含碳率最大达到51.48%,其次是高山松Pinus densata 51.31%,冷杉Abies georgei 50.79%,川滇高山栎Quercus aquifolioides的含碳率最小为48.71%,通过统计检验,4树种之间的含碳率差异显著;同一树种不同林龄之间的含碳率也存在着差异,但是变化较小,均未超过3%;不管是同一树种不同器官之间还是同一器官不同树种之间的含碳率都存在差异,但含碳率变化不大,变异系数均未超过6%;针叶树种平均含碳率普遍高于阔叶树种。     

我国珍贵树木保护中若干法律问题的思考

保护珍贵树木具有十分重要的意义,本文从立法、司法的角度,归纳了当前我国保护珍贵树木的法律制度及相关的法律责任,对于进一步完善与珍贵树木保护相关的法律规定提出了自己的设想.     

Ecological problems of tree species in protected ecosystems of Orissa, India

The tree layer vegetation of two protected ecosystems i.e. Similipal Biosphere Reserve (SBR) and Bhitarkanika National Park (BNP) of eastern ghat was analysed for structure, composition and diversity. With respect to the tree species composition the two protected ecosystems were differed from each other at the family, genera and species level. About 117 tree species representing 85 genera and 42 families were recorded in SBR. The average number of species per hectare was 32.5. However, a total of 29 tree species representing 22 genera and 16 families were recorded in BNP with an average number of species per hectare of 24.17. Species dominancy of the two protected areas was also different due to their difference in habitat condition. In SBR Shorea robusta was the most dominant species while in BNP Excoecaria agallocha was the most dominant species. Shannon-Wiener species diversity was 3.15 for Similipal and 2.314 for Bhitarkanika indicating that Similipal was highly diverse than Bhitarkanika. In general both the protected ecosystems of Orissa are highly rich in biodiversity and are characteristics of good ecological wealth of eastern ghat. Thus conservation and management practices are essential for the sustainability of their biodiversity.     

Tree species and mycorrhizal associations influence the magnitude of rhizosphere effects

Previous research on the effects of tree species on soil processes has focused primarily on the role of leaf litter inputs. We quantified the extent to which arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) tree species influence soil microbial activity and nutrient availability through rhizosphere effects. Rhizosphere soil, bulk soil, and fine roots were collected from 12 monospecifc plots (six AM and six ECM tree species) planted on a common soil at the Turkey Hill Plantations in Dryden, New York. Rhizosphere effects were estimated by the percentage difference between rhizosphere and bulk soil samples for several assays. Rhizosphere effects on soil microbes and their activities were significant for ECM species but in only a few cases for AM species. In AM tree species, microbial biomass, net N mineralization, and phosphatase enzyme activity in the rhizosphere were 10-12% greater than in bulk soil. In ECM tree species, rhizosphere effects for microbial biomass, C mineralization rates, net N mineralization, and phosphatase activity were 25-30% greater than bulk soil, and significantly greater than AM rhizosphere effects. The magnitude of rhizosphere effects was negatively correlated with the degree of mycorrhizal colonization in AM tree species (r = -0.83) and with fine root biomass (r = -0.88) in ECM tree species, suggesting that different factors influence rhizosphere effects in tree species forming different mycorrhizal associations. Rhizosphere effects on net N mineralization and phosphatase activity were also much greater in soils with pH < 4.3 for both AM and ECM tree species, suggesting that soil pH and its relation to nutrient availability may also influence the magnitude of rhizosphere effects. Our results support the idea that tree roots stimulate nutrient availability in the rhizosphere, and that systematic differences between AM and ECM may result in distinctive rhizosphere effects for C, N, and P cycling between AM and ECM tree species.     

Life history trade-offs in tropical trees and lianas

It has been hypothesized that tropical trees partition forest light environments through a life history trade-off between juvenile growth and survival; however, the generality of this trade-off across life stages and functional groups has been questioned. We quantified trade-offs between growth and survival for trees and lianas on Barro Colorado Island (BCI), Panama using first-year seedlings of 22 liana and 31 tree species and saplings (10 mm < dbh < 39 mm) of 30 tree species. Lianas showed trade-offs similar to those of trees, with both groups exhibiting broadly overlapping ranges in survival and relative growth rates as seedlings. Life history strategies at the seedling stage were highly correlated with those at the sapling stage among tree species, with all species showing an increase in survival with size. Only one of 30 tree species demonstrated a statistically significant ontogenetic shift, having a relatively lower survival rate at the sapling stage than expected. Our results indicate that similar life history trade-offs apply across two functional groups (lianas and trees), and that life history strategies are largely conserved across seedling and sapling life-stages for most tropical tree species.     

重庆缙云山常绿阔叶林群落物种多样性与土壤因子的关系

探讨了缙云山常绿阔叶林物种多样性的变化特征，并运用去势典范对应分析(DCCA)方法，分析了不同样方中土壤因子与群落多样性指数之间的关系．结果表明：(1)17个样方中物种丰富度指数是草本层最高，均匀度指数是乔木层最高．(2)土壤含水量和水解氮与乔木层物种丰富度和均匀度相关性明显，有效磷和乔木层均匀度有明显相关；全氮含量和有机质含量与草本层物种的均匀度有明显相关．(3)多酚氧化酶活性和乔木层物种的均匀度有明显相关，转化酶活性与乔木层物种丰富度和均匀度均有一定相关，多酚氧化酶活性和酸性磷酸酶活性与草本层的物种均匀度和丰富度有明显相关．图2表3参20     

宁夏六盘山8种木本植被的叶片水分利用效率

为了解宁夏六盘山地区主要树种的叶片水分利用效率（WUE）的种间和水分生境差异及季节变化,2010年6-9月份在宁夏六盘山具有半湿润气候和较多树种的香水河小流域和具有半干旱气候及较少树种的叠叠沟小流域,选择8个主要树种测定其叶片的 WUE。结果表明,（1）在香水河小流域,树种叶片 WUE 大小排序为油松 Pinus tablaeformis＞山桃 Prunus davidiana＞沙棘Hippophae rhamnoides＞辽东栎Quercus liaotungensis＞华北落叶松Larix principris-rupprechtii＞华山松Pinus armandii＞少脉椴Tilia paucicostata＞白桦Betula platyphylla;在不同生活型之间,叶片WUE的大小排序基本上呈现出灌木＞小乔木＞常绿针叶树＞落叶针叶树＞落叶阔叶树的变化规律;所有8个测试树种的叶片WUE的季节变化均为生长季初期较高,在中后期持续降低,但季节变幅随树种而异。（2）对2个小流域共有的测试树种（华北落叶松、山桃和沙棘）的叶片WUE进行了比较,结果表明存在着明显的水分生境差异,即在半干旱区极显著（p＜0.01）大于半湿润区,前者为后者的2.03倍以上。（3）对于沙棘、山桃、油松和华北落叶松,它们在较干旱气候类型立地和较干旱季节条件下都具有较高的叶片WUE,属抗旱能力较强的生态型节水树种,可选为干旱缺水区主要造林树种。此外,树种叶片WUE同时具有保守性和变异性,说明可采取适度抗旱锻炼来在一定范围内提高造林树种的WUE。