鹰咀界天然次生林自然保护区林地土壤特性研究

鹰咀界自然保护区位于沅水上游 ,是湘西南保存较好的一片天然次生林。它的存在对研究该区域天然林的培育、生物多样性保护具有重要意义。同时 ,也为森林类型涵水功能的研究提供了场地。为了摸清该保护区次生林的自然特性 ,为保护和研究积累技术资料 ,我们利用保护区自然科学资助基金对其林地土壤特性进行了调查与研究 ,将其结果报道如下。1　保护区自然概况鹰咀界自然保护区位于湖南省会同县东南部雪峰山山脉的西支南段。地理位置为北纬 2 6°46′～ 2 6°5 9′ ,东经 1 0 9°5 1′～ 1 0 9°5 8′。海拔最高 938ｍ ,最低 2 4 6ｍ ,一般在 3…     

樟树叶油地理变异的研究

对分布在福建省不同地区的樟树〔C innam omum camphora(L.)Presl〕叶油含量和主要化学成分进行分析,结果表明,J3(118°16′~119°29′)和W 1(28°18′~27°30′)交叉区域芳樟叶油含量(1.90%±0.30%)和芳樟醇含量(95.34%±1.10%)较高,可作为优良芳樟选育的重点区域;J2(117°03′~118°16′)和W 3(26°42′~25°54′)交叉区域桉樟叶油含量(1.36%±0.48%)和1,8-桉叶油素含量(10.44%±17.28%)较高,可以作为优良桉樟选育的重点区域。J2和W 2(27°30′~26°42′)交叉区域樟脑叶油含量(1.13%±0.65%)和樟脑含量(4.80%±13.97%)较高,可以作为优良脑樟选育的重点区域;J4(119°29′~120°43′)和W 6(24°18′~23°31′)交叉区域黄樟叶油含量(1.05%±0.34%)和黄樟油素含量(9.01%±16.73%)较高,可以作为优良黄樟选育的重点区域。樟树叶油含量和主成分类型及含量呈明显的地理分布。     

西双版纳28种野生经济树种的物候观察

西双版纳位于云南南部边缘,地理位置为北纬21°09′～22°36′、东经99°58′～101°50′之间。面积19690平方公里,该地地处热北缘,长期受热带季风控制,气候条件十分优越。植物资源极其丰富。在西双版纳海拔800米以下的地区,降雨量在1500毫米左右,年平均气温为20℃左右,相对湿度较大。植被分类划分为热带雨林和热带季雨林。多年生植物呈现出大都无冬季休眠     

神农架自然保护区两栖爬行动物初步调查

神农架自然保护区位于湖北省西部,东经110°3′—110°34′,北纬31°22′—31°37′。整个区域属大巴山脉东段的延伸部分,南临长江西陵峡,北依汉水。区内最低海拔420米,一般海拔在1700米左右,主峰神农顶海拔3105.4     

广东阳春鹅凰嶂自然保护区种子植物区系研究

鹅凰嶂自然保护区位于广东省阳春市境内 (1 1 1°2 1′2 9″～ 1 1 1°3 6′0 3″E ,2 1°5 0′3 6″～ 2 1°5 8′40″N) ,为北热带地区。计有维管植物 2 1 0科 75 4属 1 5 80种 (包括亚种与变型 ) ,其中种子植物有 1 72科 681属 1 44 8种。研究分析和讨论了本区主要植被类型、种子植物区系及珍稀濒危植物 ,其种子植物区系特征是 :种类组成比较丰富 ,地理成分复杂 ,联系广泛 ,以热带成分占绝对优势 ,是典型的热带北缘区系性质 ;植被类型以山地雨林为主 ;区系起源古老 ,原始类群丰富 ;特有性比较高 ,珍稀濒危植物明显。建议对一些濒危物种采取有效的保护措施。     

湖南莽山自然保护区的水生维管束植物——多样性及其生境特征

莽山自然保护区位于湖南省宜章县境内 (2 4°52′0 0″～ 2 5°0 3′12″N,112°4 3′19″～ 113°0 0′10″E) ,属南岭支脉。作者对该地区水生维管束植物及其生境进行了考察 ,采集到水生沼生维管束植物30科 4 7属 6 7种 ,其中 30种为莽山地区新记录。在比较沼泽和湖泊水生植物群落结构特点的基础上 ,讨论了沼泽作为水生植物重要生境的意义 ,建议对作为珍稀濒危水生植物重要产地的长江以南山地沼泽采取有效的保护措施     

太行山猕猴的肥满度

太行山猕猴自然保护区位于河南省西北部 ,已于 1 998年升格为国家级自然保护区。地理坐标为北纬 3 4°5 4′～ 3 5°2 0′,东经 1 1 0°0 2′～ 1 1 4°1 0′。保护区内生活有国家二级保护动物太行山猕猴约 1 5 0 0余只 ,现已成为我国乃至世界野生猕猴分布的最北限[1 ] 。该种群属华北亚种 (Ｍａｃａｃａｍｕｌａｔｔａｔｃｈｅｌｉｅｎｓｉｓ) ,为我国特产动物 ,不仅在生理、生态、行为、形态等方面与南方种群有明显差异 ,且具有独特的、其它地区猕猴无法替代的遗传多样性[2 ] 。近年来 ,由于环境恶化及诸多人为因素的影响 ,致使该区域猕猴…     

蛇雕繁殖生态的初步观察

蛇雕(Ｓｐｉｌｏｒｎｉｓｃｈｅｅｌａ)属隼形目鹰科猛禽。有关其繁殖行为研究,到目前未见报道。笔者于1997～1998年,在贵州茂兰国家级自然保护区内,对蛇雕东南亚种(Ｓｐｉｌｏｒｎｉｓｃｈｅｅｌａｒｉｃｋｅｔｔｉ)的繁殖生态作了初步观察,现将观察情况报道如下。1　自然概况茂兰保护区位于贵州南部的荔波县境内。东经107°10′10″～108°05′40″,北纬25°09′20″～25°20′50″。海拔500～1100ｍ,最高点为肯西山1170ｍ。林区总面积2100ｈｍ2。为中亚热带季风湿润气候。年平均气温153℃,年降雨量1750ｍｍ左右,集中于4～10月,年平均相对…     

梧桐科植物在中国的地理分布

对中国梧桐科植物的地理分布进行研究 ,指出中国梧桐科植物的分布区 ,东起台湾的北部 (1 2 2°1 0′E) ,西至西藏的墨脱 (95°3 0′E ,2 9°2 0′N) ,北起河北的东陵和小五台山 (约 40°2 0′N) ,南达西沙群岛的永兴岛(约 1 6°1 0′N)。其分布范围主要在热带、亚热带 ,只有少数种类可分布到温带。主要根据《中国种子植物属的分布区类型》的划分原则 ,把中国梧桐科植物野生各属划分为 1 0个类型。且对中国梧桐科植物一些属的分布格局进行探讨。     

神农架的部分大型真菌

(一)基本特征湖北省西部的神农架地区,位于东经109°56′—110°58′,北纬31°15—31°57′之间。地处我国亚热带向北温带过渡地带,又是东部低山丘陵区向西部高山区过渡区域。神农架系大巴山之余脉,最高的无名峰     

广东鼎湖山马尾松年轮元素含量及其相关性研究

The concentrations of the elements in the annual rings of Pinus massoniana reflect the influence of both regional factors and species characteristics in absorbing,accumulating and distributing elements.The changes of environmental factors may result in concentration changes of elements in tree rings.Therefore,variations of tree ring element concentration may provide some clue in studying environmental changes.Some of eight elements studied are strongly correlated with others,the reason of which might be their similar structural and enzymatic functions in the plant cell,similar chemical properties and similar or opposite reaction to variations in some environment factors.     

The history of pollution elements in Zhengzhou,China recorded by tree rings

Several tree ring samples in Zhengzhou, China, were collected to research the pollution elements variation history and the application of dendrochemistry in urban environmental pollution research. Bark and soil samples were also collected in the study area. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to analyse the concentrations of pollution elements in Cedrus deodara (Roxb.). The results indicated that the variations in pollution elements concentrations in the tree rings were roughly consistent with the history of the Zhengzhou No. 3 cotton mill (GM3). The autocorrelation coefficients determined for the element concentrations indicated that Zn and Pb were translocated within tree rings to a certain degree, especially Zn, and that Cu was not translocated within tree rings. We also found that the accumulation of Pb in the bark was extremely high, which indicated that trees are prone to Pb absorption from the atmosphere, not soil. This research reveals the history of different pollution elements in the environment and demonstrates that dendrochemical methods represent an effective component in an environmental monitoring programme.     

Discrete versus continuous analysis of anatomical and δ13C variability in tree rings with intra-annual density fluctuations

Intra-annual density fluctuations (IADFs) are anomalies of tree rings where wood density is abruptly altered after sudden changes in environmental conditions. Their characterisation can provide information about the relationship between environmental factors and eco-physiological processes during tree growth. This paper reports about the variability of anatomical traits and stable carbon isotopic composition along tree rings as resulting from the application of two different methodological approaches: (a) the separation of each ring into different regions (earlywood, latewood and IADF) and the comparison of anatomical and isotopic parameters measured in those specific sectors and (b) the analysis of such features in continuum along ring width. Moreover, different parameters of vessels (i.e. ecd—equivalent circle diameter, elongation, sphericity and convexity of vessel lumen) were considered to identify those more appropriate for the representation of intra-annual anatomical variations. The analysis was conducted on Arbutus unedo L. growing on the Elba Island (Italy); tree rings of this species form IADFs with features clearly responsive to the environmental conditions experienced during plant growth. Results showed that the first approach, although more suitable to obtain data for subsequent statistical comparisons and for the calculation of correlations with environmental parameters, suffers from elements of subjectivity due to the size and position of the selected tree-ring regions. The in continuum method allows a clearer identification of the variation of tree-ring properties along ring width. Regarding anatomical parameters, shape indexes were not suitable indicators of intra-annual variability. The overall analysis suggested that using both methodologies in synergy helps to gain complete information and avoid misleading interpretations of IADFs in tree rings.     

树木年轮中的微量元素含量与克山病关系的初步分析

森林是陆地生态系统中的一个重要组成部分,在一定程度上可以说它是“历史的见证”,因为在森林中记录了过去生态环境的一些变化和特点。 树木年轮是过去环境记录的一个重要各面,大家知道,通过观察树木年轮,可分析研究近千年来地球上气候的变化。这一方法在国内外已得到广泛的应用。但是从生物地球化学观     

Long Tree-Ring Chronologies Provide Evidence of Recent Tree Growth Decrease in a Central African Tropical Forest

It is still unclear whether the exponential rise of atmospheric CO₂ concentration has produced a fertilization effect on tropical forests, thus incrementing their growth rate, in the last two centuries. As many factors affect tree growth patterns, short -term studies might be influenced by the confounding effect of several interacting environmental variables on plant growth. Long-term analyses of tree growth can elucidate long-term trends of plant growth response to dominant drivers. The study of annual rings, applied to long tree-ring chronologies in tropical forest trees enables such analysis. Long-term tree-ring chronologies of three widespread African species were measured in Central Africa to analyze the growth of trees over the last two centuries. Growth trends were correlated to changes in global atmospheric CO₂ concentration and local variations in the main climatic drivers, temperature and rainfall. Our results provided no evidence for a fertilization effect of CO₂ on tree growth. On the contrary, an overall growth decline was observed for all three species in the last century, which appears to be significantly correlated to the increase in local temperature. These findings provide additional support to the global observations of a slowing down of C sequestration in the trunks of forest trees in recent decades. Data indicate that the CO₂ increase alone has not been sufficient to obtain a tree growth increase in tropical trees. The effect of other changing environmental factors, like temperature, may have overridden the fertilization effect of CO₂.     

Trace elements distribution in tropical tree rings through high-resolution imaging using LA-ICP-MS analysis

BackgroundThe distribution of trace elements in tree rings although poorly known may be useful to better understand environmental changes, pollution trends, long-term droughts, forest dieback processes, and biology of trees.MethodLaser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is used for imaging micronutrients and potentially toxic elements distribution, allowing the investigation of trace elements at high spatial resolution within the tree rings. To ensure a more efficient determination of micronutrients and potentially toxic elements, LA-ICP-MS instrumental conditions were optimized and carbon, a major element in wood, is used as an internal standard during analysis to correct for random fluctuations.ResultsSpatial distributions maps of Ba, Cu, Fe, Mn, Ni, and Pb in growth layers of six tropical tree species were built-up using the LA-iMageS software, namely: Amburana cearensis (Fabaceae), Cedrela fissilis (Meliaceae), Hymenaea courbaril (Fabaceae), Maclura tinctoria (Moraceae), Parapiptadenia zehntneri (Fabaceae), Peltogyne paniculata (Fabaceae). A correlation between the trace element composition and different cell types (parenchyma, fiber, and vessel) was distinctly observed. It was observed a general pattern of Ba, Cu, Ni, Mn, and Pb accumulation mainly in the axial parenchyma and vessels. But the elemental composition of xylem cells is strongly species dependent. The multivariate analysis also points to a distinct accumulation of minerals between heartwood and sapwood in the same species.ConclusionsImaging both essential and deleterious element distributions in the tree rings may improve visualization and can effectively contribute to understanding the lifetime metabolism of trees and evaluating the effects of environmental changes related to climatic seasonality, pollution, and future paleoclimate reconstructions.     

天目山柳杉树轮δ13C年序列差异

对天目山3株柳杉树轮δ¹³C年序列分别进行了测定,分析了柳杉树轮δ¹³C年序列变化的异同及其原因.结果表明,在1837～1982年的共同时段,3个树轮δ¹³C年序列彼此间相关系数为：r₁₂=0.47,r₁₃=0.65,r₂₃=0.52 (n=146),都通过了显著性水平α=0.001的信度检验.用多项式拟合法去除原δ¹³C年序列中的高频变化后,所得3个低频序列间高度正相关;原δ¹³C年序列与拟合序列的差值序列即高频序列间也显著正相关,相关系数均达到0.79～0.99,说明气候因素引起树轮δ¹³C年序列的高频变化及大气CO₂浓度引起的低频变化对不同的柳杉个体是共同的.3株树轮δ¹³C年序列间的差异主要是树木立地处局部环境条件的不同所造成的,但是局部环境条件所引起的树轮δ¹³C年序列间的个性差异对其共性变化影响较小.所以,3个树轮δ¹³C年序列间的个性差异,并不影响树轮δ¹³C年作为气候变化研究代用资料的适宜性及重建历史气候结果的可靠性与一致性.     

Anatomical characteristics of xylem in tree rings and its relationship with environments

The anatomical traits of xylem are the characteristics of tree rings at the cellular and subcellular scales, and are often reflection of environmental signals. Studying the relationships between anatomical traits of xylem and environmental change not only provide physiological explanations to the statistics in dendroclimatology, but can also provide a new vision for studying the adaptation process and response strategies of tree growth to climate change. In this paper, with the relationships between the anatomical characteristics of xylem in tree-rings (cell chronology) and climate change as a main thread, we first outline the basic principles and mechanisms of wood anatomical features to record environmental signals, and expounded the basic methods involved in the process of xylem anatomy. Secondly, we discuss the relationship between the anatomical features of xylem and climate factors. We then propose the following as possible directions of future research based on the existing knowledge gap in the topical area: (1) to explore the temporal and spatial variations in the anatomical characteristics of xylem in tree-rings along radial and tangential directions and the relationships with environmental changes; (2) to explore the threshold of tree growth response to environmental plasticity and adaptation processes; (3) to assess the synergistic and antagonistic effects as well as the formation mechanisms of climate response among different tree-ring proxies, and to determine the specific roles and contributions of major climatic factors during different periods of tree-ring formation.     

Seasonal profiles of sulphur, phosphorus, and potassium in Norway spruce wood

Seasonal profiles of sulphur, phosphorus, and potassium content in the wood of trees have been established for the first time. This became possible by using a novel laser ablation system coupled to HR-ICP-MS for measuring these elements in Norway spruce drill cores. This technique combines excellent spatial resolution with superior detection power, and makes it possible to measure low element concentrations even in relatively narrow annual rings. Despite its low quantity in wood, sulphur is an important macronutrient for plants and seems to display seasonal variations of its concentration, which correspond to actual theories of sulphur metabolism in plants. A similar seasonal pattern was also found for phosphorus, another crucial element in tree nutrition. This was unexpected, because it was previously assumed that the distribution of phosphorus remains constant throughout the year. Potassium, the third element measured, seems to be especially accumulated in the latewood. The profiles presented in this article suggest a seasonal variation, revealing some new aspects of Norway spruce (PICEA ABIES) metabolism.     

Anatomical characteristics of xylem in tree rings and its relationship with environments北大核心CSCD

The anatomical traits of xylem are the characteristics of tree rings at the cellular and subcellular scales, and are often reflection of environmental signals. Studying the relationships between anatomical traits of xylem and environmental change not only provide physiological explanations to the statistics in dendroclimatology, but can also provide a new vision for studying the adaptation process and response strategies of tree growth to climate change. In this paper, with the relationships between the anatomical characteristics of xylem in tree-rings (cell chronology) and climate change as a main thread, we first outline the basic principles and mechanisms of wood anatomical features to record environmental signals, and expounded the basic methods involved in the process of xylem anatomy. Secondly, we discuss the relationship between the anatomical features of xylem and climate factors. We then propose the following as possible directions of future research based on the existing knowledge gap in the topical area: (1) to explore the temporal and spatial variations in the anatomical characteristics of xylem in tree-rings along radial and tangential directions and the relationships with environmental changes; (2) to explore the threshold of tree growth response to environmental plasticity and adaptation processes; (3) to assess the synergistic and antagonistic effects as well as the formation mechanisms of climate response among different tree-ring proxies, and to determine the specific roles and contributions of major climatic factors during different periods of tree-ring formation.