Climate and vegetation in China IV. Distribution of tree species along the thermal gradient

The aim of this study was to examine correlations between vegetational zones and thermal climate on the basis of analysis of the thermal distribution of main-component trees in each zone. The whole and main thermal distribution ranges for 73 tree species were obtained from their distributions along the warmth index (WI) gradicnt. Cluster analysis using the WI values at the upper and lower limits of the main distribution ranges as parameters gave seven species groups. The geographical distributions of the species in each group were described. Moreover, the frequency distribution curves of the seven species groups were determined along the WI grandient, and four borderlines (lines I, II, III and IV) were found among them. The WI values at the lines I, II and IV were 50, 90, 175°C month, respectively, and corresponded to boundaries between the subarctic and cool-temperate zones (I), the cool-and warm-temperate zones (II) and the warmtemperated and subtropical/tropical zones (IV), respectively. Line III corresponded to a WI of 135°C month. The WI values at the forest limit and at the lower limit of the subarctic forest were estimated, and their averages were 15.2 and 49.6°C month, respectively. In conclusion, thermal climatic zones in China could be divided by the following WI values: alpine (arctic) zone, WI<15; subarctic zone, 15–50; cool-temperate zone, 50–90; warm-temperate zone, 90–175; subtropical/tropical zone >175°C month.     

中国热带森林植被类型研究历史和划分探讨

热带森林是我国森林植被的重要组成部分,明确其森林植被类型分类对于生物多样性维持机制研究和保护管理等都具有重要意义。该文以中国热带森林植被分类研究中存在的问题为出发点,通过阐述我国各省区植被类型分类的研究历史,在综合考虑多种生物和非生物影响因素的基础上,提出一个新的热带森林植被类型分类框架以供探讨。结果表明:(1)尽管针对我国热带森林的分布范围和群落特征等都已开展了诸多研究,但对我国热带森林植被类型的划分依据和分类体系仍存在争议。(2)尽管我国的热带森林都处于季风气候区带内,但许多热带地区的森林植被类型并不只是受季风影响,而是气候带、关键气候因子、地形、土壤反馈和物种适应等多种因素共同作用的结果。(3)我国的热带森林植被包括5个植被型,即非典型性热带雨林、热带季雨林、热带山地雨林、热带山顶苔藓矮林(热带云雾林)和热带针叶林,其中热带季雨林植被型包含4种植被亚型[热带落叶季雨林、热带半落叶(半常绿)季雨林、热带常绿季雨林和热带石灰岩(石山)季雨林]。(4)阐明了上述热带森林植被型和植被亚型在我国各省区的分布情况,并提出未来有必要对人工恢复后的热带森林进行评估和植被类型划分。综上所述,该文提出一个新的热带森林植被类型分类框架,以期为今后基于不同地区开展热带森林比较研究提供参考。     

Changes in the distribution of South Korean forest vegetation simulated using thermal gradient indices

To predict changes in South Korean vegetation distribution, the Warmth Index (WI) and the Minimum Temperature of the Coldest Month Index (MTCI) were used. Historical climate data of the past 30 years, from 1971 to 2000, was obtained from the Korea Meteorological Administration. The Fifth-Generation National Center for Atmospheric Research (NCAR) /Penn State Mesoscale Model (MM5) was used as a source for future climatic data under the A1B scenario from the Special Report on Emission Scenario (SRES) of the Intergovernmental Panel on Climate Change (IPCC). To simulate future vegetation distribution due to climate change, the optimal habitat ranges of Korean tree species were delimited by the thermal gradient indices, such as WI and MTCI. To categorize the Thermal Analogy Groups (TAGs) for the tree species, the WI and MTCI were orthogonally plotted on a two-dimensional grid map. The TAGs were then designated by the analogue composition of tree species belonging to the optimal WI and MTCI ranges. As a result of the clustering process, 22 TAGs were generated to explain the forest vegetation distribution in Korea. The primary change in distribution for these TAGs will likely be in the shrinkage of areas for the TAGs related to Pinus densiflora and P. koraiensis, and in the expansion of the other TAG areas, mainly occupied by evergreen broad-leaved trees, such as Camellia japonica, Cyclobalanopsis glauca, and Schima superba. Using the TAGs to explain the effects of climate change on vegetation distribution on a more regional scale resulted in greater detail than previously used global or continental scale vegetation models.     

Climate and vegetation in China II. Distribution of main vegetation types and thermal climate

The authors examined relationships between Kira's warmth index (WI) and four other important thermal indices: the sums of daily mean temperatures above 5°C and 10°C, Thornthwaite's potential evapotranspiration (PE) and Holdridge's annual biotemperature. The thermal records of 671 meteorological stations evenly located all over China were used to make these comparisons. Close correlations were found within the four relationships, and accordingly WI was used to analyse the thermal distributions of the main vegetation types. Vegetation types around the 671 stations were read from a vegetation map with a scale of 1/4000000. Vegetation types at 269 stations corresponded to the natural or seminatural vegetation, and 29 vegetation types were distinguished by arranging the 269 data into the same or similar types. The geographical distribution of these 29 types and the corresponding main climatic features were described. The relations between WI and distribution of these vegetation types were discussed in detail. As a result, WI values (°C month) corresponding to the vegetation zones could be summarized as follows: (1) arctic or alpine vegetation zone: 0–15; (2) boreal or subalpine vegetation zone: 15-(50–55); (3) cool-temperate vegetation zone: (50–55)–(80–90); (4) warm-temperate vegetation zone: (80–90)–(170–180). These values almost coincided with Kira's values. Chinese postgraduate student in Japan sent by the Chinese Government.     

海南岛尖峰岭地区热带植被生态系列的研究

 本文通过对海南岛尖峰岭地区热带植被随环境条件递变而变化的分析,反映出在一较短的水平距离内植被变化的多样性,并通过群落生态学方法的分析,说明尖峰岭地区的植被在种类组成、多样性、群落外貌等方面都具有较典型的热带性质,但在群落的结构方面则比典型的热带雨林逊色,说明它是地处热带北缘和在季风气候影响下的必然结果。用重要值方法来描述热带植物群落,其结果较为理想。研究该地区热带植被的特点,对认识、了解我国的热带植被和经营热带林等方面,提供了一些理论依据。     

Study of changes in life zone distribution in north-east China by climate–vegetation classification

Life zones and their changes in distribution in north-east China were studied based on climate–vegetation relationships. The warmth index (WI) and aridity index (the ratio of evaporation [evaporation rate, ER] to precipitation) were used to represent the site condition. The typical site condition of each vegetation type was determined as the classification criterion. The boundaries of the four potential vegetation zones were estimated based on the combinations of WI and ER in relation to vegetation (i.e. cold-temperate conifer forest zone, temperate broad-leaved conifer mixed forest zone, warm-temperate deciduous forest zone, and temperate steppe zone). The distribution changes in vegetation zone caused by human activities were estimated by comparing the potential vegetation with the actual one. The percentage cover of forest has shrunk from about 70% to the present 27%. About 23% of the study area was replaced by agricultural vegetation and industrial use. Nearly half of the region could have been covered by broad-leaved conifer mixed forest which was shrunk to a small area, less than 5% of the region. The broad-leaved deciduous forest zone in the southern part could have occupied about 7% of the area, and had almost no virgin stand.     

Vegetation Dynamics and Forest Landscape Restoration in the Upper Min River Watershed, Sichuan, China

The Upper Min River (UMR) watershed, with an area of 23,000 km² in the Upper Yangtze basin in Sichuan province, is ecologically and environmentally fragile. This situation is due to natural catastrophes and increasing anthropogenic disturbance. Forest cover has decreased dramatically, especially along the main Min River. Restoration of the vegetation in a watershed needs to consider the natural vegetation distribution and dynamics. In the UMR watershed, 625 sample plots were randomly placed to study the soil types, current vegetation distribution, vegetation dynamics, afforestation, and potential tree species for restoration. We investigated the relationship between vegetation types and soil orders, predicted the percentages of potential tree species for forest landscape restoration using logistic regression, identified priority areas for rapid restoration, and pinpointed areas for forest restoration where low precipitation is a constraint. The results showed that the vegetation types were well correlated with soil orders, and the latter could be used to deduce the potential vegetation for areas of degraded secondary forest. Priority areas for rapid restoration were demonstrated, and the difficult areas with precipitation as a limiting factor for vegetation restoration were specified. Suitable tree species were suggested for restoration on different soil orders at different elevations.     

广西常绿阔叶林分类系统及特点

常绿阔叶林是广西分布最广泛、最为复杂多样的植被类型.遵循《中国植被》一书的植被分类原则,并参考宋永昌先生的《中国常绿阔叶林分类试行方案》.根据高级单位以生态外貌、中级单位以优势度类型、低级单位以特征种组的分类原则,将广西常绿阔叶林划分出5个植被亚型、11个群系组和102个群系.在5个植被亚型中,典型常绿阔叶林和季风常绿...     

中国东北植被生态学研究中的焦点问题

中国东北植被经过半个多世纪的系统研究,但有关植被生态学一些争论性问题尚未统一．本文仅就作者近年来研究工作涉及到的内容和关注的问题,提出一些看法：1)中国东北植被地带性分布规律可用Kira的温暖指数(WI）、寒冷指数(CI）和作者的湿度指数(HI)进行定量解释．2)大兴安岭北部山地,在海拔1400m以上存在冻原植被,是作者于1963年首次发现的我国第三块冻原植被,其WI<15℃·月．3)大小兴安岭植被分界线是我国植被区划中第一级分区界线,其位置在爱辉-果松沟-嫩江以南附近,WI为45℃·月．4)大兴安岭植被地带性分异显著,南段、中段为典型草原地带和森林草原地带,北段为针叶林地带,HI值分别为3．5～5．5、5．5～7．5、>7．5mm／℃·月．大兴安岭东麓阔叶林是森林草原带上的森林植被类型．5)东北东部山地岳桦林是山地植被垂直带谱重要组成部分之一,是山地森林垂直分布林线,WI为20～15℃·月为地带性植被类型,而WI>20℃·月为非地带性植被类型．6)内蒙古浑善达克沙地云杉林是陆地上非常罕见的森林生态系统类型,但这种云杉林究竟是哪一树种组成,在中国植物分类上一直是个争论性问题,作者通过核型分析和同工酶实验进一步证明是一个新种即沙地云杉Picea mongolica(H．Q．Wu)W．D．Xu,cmb．NOV．-Picea meyeri Rehd．et Wils var．mogolica(H．Q．Wu)．     

中国东北主要植被类型的分布与气候的关系

本文根据吉良的热量指标和作者提出的湿度指数,研究了我国东北主要植被类型的分布与气候之间的关系：1．确定了东北地区10个水平地带性植被类型的热量分布范围和水热指标的平均值。2．研究了东北山地垂直地带性植被类型的水热指标分布特点,并用定量指标讨论了东北东部山地岳桦林带的分布、大兴安岭存在山地冻原和东北植被区域的分界线问题。