九龙大雾山北坡的植物群落

九龙大雾山北坡的植物群落可划分为南亚热带常绿阔叶林、南亚热带山地常绿阔叶林、南亚热带常绿针叶林、南亚热带灌丛,以及南亚热带山坡草地等几个群落类型,它们均属于次生性植被,是华南南亚热带植被的主要代表类群。     

内伶仃岛主要植被及群落类型的特征和分布

广东省内伶仃岛位于珠江口伶仃洋的东部,属南亚热带季风气候区,其自然植被的主要类型有：南亚热带常绿针叶林、南亚热带针阔叶混交林、南亚热带常绿阔叶林、南亚热带红树林、南亚热带竹林、南亚热带常绿灌丛、南亚热带灌草丛、滨海砂生灌草丛等,包括８个植被亚型、１８个群系。人工植被主要有台湾相思林等４个群系,以及果园林４类、作物园４类。地带性植被为南亚热带常绿阔叶林;优势植被类型为台湾相思林、马尾松林,两者的建群种均为衰退种群,已形成多个发育阶段。论文对各主要植被类型及群落结构特征进行分析。     

内伶仃岛主要植被及姥落类型的特征和分布

广东省伶仃岛位于不拘珠江口伶仃洋的东部,属南亚热带季风气候区,其自然植被的主要类型有：南亚热带常绿针叶林、南亚热带针阔叶混交林、南亚热带常绿阔叶林、南亚热带红树林、南亚热带竹林、南亚热带常绿灌丛、南亚热带灌草丛、滨海砂生灌草丛等,包括８个植业型、１８个群系。人工植被主要有台湾相思林等４个群系,以及果园林４类、作物园４类。地带性植被为南亚热带党绿阔叶林;优势植被类型为台湾相思林、马尾松林,两者的建群     

广东省海岸带沙生植被的改造利用

广东省海岸带沙生植被的改造利用邓义,陈树培,梁志贤（中国科学院华南植物研究所）１生境条件广东省海岸线（包括海南岛）长达６０００多ｋｍ,约占全国海岸线总长度的１／３。地处热带和南亚热带,气候的基本特点是：光照充足、热量丰富（由北至南年均温２１～２５℃）...     

珠江口内伶仃岛植被

内伶仃岛现状植被主要是:南亚热带常绿阔叶林,南亚热带针叶林,红树林,南亚热带灌丛,南亚热带山坡草地,滨海砂生灌草丛,人工林。文内还阐述了猕猴生态环境和植物资源。     

粤西南亚热带森林演替过程中的生物量与净第一性生产力动态

以粤西黑石顶自然保护区为对象,探讨了南亚热带森林群落演替系列上3个主要演替阶段的代表类型：针叶林(马尾松群落)、针阔混交林(马尾松+吊皮椎+木荷+枫香群落)、南亚热带常绿阔叶林(粘木+小叶胭脂+光叶红豆+黄果厚壳桂群落)的生物量和净第一性生产力及其分配规律。结果表明,针叶林生物量为246．697t·hm^-2,净第一性生产力为14．715t·hm^-2·yr^-1;针阔混交林生物量为287．367t·hm^-2,净第一性生产力为17．179t·hm^-2·yr^-1;常绿阔叶林生物量为357．976t·hm^-2,净第一性生产力为18．730t·hm^-2·yr^-1,可见黑石顶自然保护区南亚热带3种森林群落的发展阶段已比较接近,即针叶林、针阔混交林较为成熟,常绿阔叶林相对年轻,在不受或低度外界干扰的情况下,随着森林群落的正向演替,其生物量和净第一性生产力均呈增加趋势。     

论季雨林的水平地带性

季雨林是受制于湿度因子的经度地带性植被类型,它是随着湿度条件的下降由热带雨林向热带疏林过渡的居间类型,而不是受制于温度因子的纬度地带性植被类型,不是随着温度条件的下降由热带雨林向亚热带常绿阔叶林过渡的居间类型。我国南亚热带的榕树群系、黄桐群系,以及热带北缘的青皮群系均不应是季雨林,前二者是典型的南亚热带低地常绿阔叶林或南亚热带雨林,后者则是热带雨林的一分类群。     

关于华南的热带与亚热带分界线问题

关于华南的热带与亚热带的分界线问题,地理学工作者和植物学工作者都发表过一些文章,从各个角度进行讨论。华南的地植物学工作者多赞成以雷州半岛北部作为华南热带与亚热带的分界线,把广东大陆的亚热带分为两个亚带,即华南南亚热带常绿季雨林亚带和南岭山地中亚热带常绿阔叶林亚带。侯宽昭、徐祥浩(1955年)首先从地植物学角度提出,华南的热带与亚热带的分     

全球气候变化的中国自然植被的净第一性生产力研究

本文根据已建立的植物生理生态学特点与水热平衡关系的植物净第一性生产力模型对中国自然植被的净第一性生产力现状及全球变化后的自然植被的净第一性生产力进行了分析,给出了中国陆地生态系统自然植被的净第一性生产力在全球气候变化条件下的变化图景,为合理开发、利用自然资源,以及监测和预测中国陆地生态系统自然植被净第一性生产力的变化及应采取的策略提供了科学依据。     

南亚热带六种典型人工林碳收支研究

集成生物圈模型(IBIS)有效整合了陆地生态系统的地表过程、植被冠层过程、植被物候和植被动态,被广泛应用于研究生态系统的碳平衡和碳收支情况。在采集研究区域气象数据、植被功能型和光合参数、叶面积指数、各植被类型枯落物月分解比例、土壤参数的基础上,运用IBIS 模型对广州市六种林分的总生产力(GPP)、净第一性生产力(NPP)、生态系统净生产力(NEE)进行了预测,结合每种林分碳储量、年固碳量的野外实测数据,对模型的运行结果进行了验证。结果表明,阔叶林的GPP 和NPP 均高于针叶林;从时间序列来看,NPP 和NEE 月变化数据呈双峰曲线,两个峰值分别出现在春季和秋季,而夏季较少,这可能与夏季的自养呼吸和异养呼吸高有关。该研究有助于理解位于南亚热带植被的碳动态规律。     

Uncertainty in Calculations of Net Primary Production for Grasslands

Net primary production (NPP) is a fundamental characteristic of all ecosystems and foundational to understanding the fluxes of energy and nutrients. Because NPP cannot be measured directly, researchers use field-measured surrogates as input variables in various equations designed to estimate ‘true NPP’. This has led to considerable debate concerning which equations most accurately estimate ‘true NPP’. This debate has influenced efforts to assess NPP in grasslands, with researchers often advocating more complex equations to avoid underestimation. However, this approach ignores the increase in statistical error associated with NPP estimates as a greater number of parameters and more complex mathematical functions are introduced into the equation. Using published grassland data and Monte Carlo simulation techniques, we assessed the relative variability in NPP estimates obtained using six different NPP estimation equations that varied in both the number of parameters and intricacy of mathematical operations. Our results indicated that more complex equations may result in greater uncertainty without reducing the probability of underestimation. The amount of uncertainty associated with estimates of NPP was influenced by the number of parameters as well as the variability in the data and the nature of the mathematical operations. For example, due to greater variability in the field-measured belowground data than aboveground data, estimates of belowground NPP tended to have more uncertainty than estimates of aboveground NPP. An analysis in which the input data were standardized allowed us to isolate the details of the calculations from the variability in the data in assessing the propagation of uncertainty. This analysis made clear that equations with product terms have the potential to magnify the uncertainty of the inputs in the estimates of NPP although this relationship was complicated by interactions with data variability and number of parameters. Our results suggest that more complex NPP estimation equations can increase uncertainty without necessarily reducing risk of underestimation. Because estimates can never be tested by comparison to “true NPP”, we recommend that researchers include an assessment of propagation of statistical error when evaluating the ‘best’ estimation method.     

鼎湖山黄果厚壳桂群落的生物量

用样木收获法和相关生长法测定并推算了鼎湖山黄果厚壳桂群落的生物量和净生产量.结果表明,群落的生物量是195.97(t·ha~(-1)),净生产量20.64(t·ha~(-1),·a~(-1)).     

Decreasing Net Primary Production in forest and shrub vegetation across southwest Australia

Monitoring changes in the terrestrial carbon cycle and vegetation health can only be undertaken over large areas and on a regular basis using ecological indicators derived from satellite-based sensors. Climate conditions in Mediterranean ecosystems have undergone, and are projected to undergo, significant change in the future with marked impacts on forest and shrubland vegetation. In the southwest of Australia (SWAU), endemic tree species have experienced significant declines in health and mortality since the early 1990s primarily due to these climatic changes. In this paper we examine trends in Net Primary Production (NPP) from 2000 to 2011 as an indicator of productivity and health condition of the woody vegetation across the SWAU region. To do so, we examine NPP estimates derived from satellite imagery and climate data to answer the questions: (1) what is the extent and rate of change in NPP for the SWAU region over the study period, and (2) how important is fire as a contributing factor in the observed trends? Our results suggest that, similar to the global trend in Mediterranean ecosystems, between 2000 and 2011, overall NPP declined across the study region, with the majority of declines occurring in the ecological transition zone between trees and shrubs. Twenty-six percent of the 37,042 square kilometre of woody vegetation that showed a declining NPP trend, was affected by fire. The overall rate of NPP decline for the region was estimated to be −0.38 megaton C per year since 2000, indicating a reduction in the capacity of the region to act as a carbon sink. Under climate change projections, the observed decline trends are likely to continue and our results suggest that the carbon storage potential in this region is gradually decreasing following an ecological shift from tall tree-dominated to lower shrub-dominated vegetation.     

Above- and Belowground Net Primary Production in a Temperate Mixed Deciduous Forest

Our current ability to detect and predict changes in forest ecosystem productivity is constrained by several limitations. These include a poor understanding of belowground productivity, the short duration of most analyses, and a need for greater examination of species- or community-specific variability in productivity studies. We quantified aboveground net primary productivity (ANPP) over 3 years (1999–2001), and both belowground NPP (BNPP) and total NPP over 2 years (2000–2001) in both mesic and xeric site community types of the mixed mesophytic forest of southeastern Kentucky to examine landscape variability in productivity and its relation with soil resource [water and nitrogen (N)] availability. Across sites, ANPP was significantly correlated with N availability (R² = 0.58, P = 0.028) while BNPP was best predicted by soil moisture content (R² = 0.72, P = 0.008). Because of these offsetting patterns, total NPP was unrelated to either soil resource. Interannual variability in growing season precipitation during the study resulted in a 50% decline in mesic site litter production, possibly due to a lag effect following a moderate drought year in 1999. As a result, ANPP in mesic sites declined 27% in 2000 compared to 1999, while xeric sites had no aboveground production differences related to precipitation variability. If global climate change produces more frequent occurrences of drought, then the response of mesic sites to prolonged moisture deficiency and the consequences of shifting carbon (C) allocation on C storage will become important questions.     

Modeling the Values of Net Primary Production for the Zonal Vegetation of European Russia

Several modern approaches to the problem of estimating the net primary production of terrestrial ecosystems are discussed. A method for predicting the dynamics of this parameter as a function of radiation balance and annual evapotranspiration is described. The values of annual carbon by the zonal vegetation of European Russia are calculated in two ways: by methods based on the empirically determined relationships between the annual average values of climatic parameters and net primary production and on the basis of models describing carbon flows between the compartments of ecosystems. The model estimations of net primary production are compared with experimental data.     

香港桃金娘灌木群落植物生物量和净第一性生产量

本文研究香港桃金娘灌木林植物生物量和净第一性生产量。结果表明：（１）桃金娘茎的直径与高度与各组分的生物量有明显的相关关系。（２）桃金娘叶子占地上部活植物生物量的２０．２％,花和果如果以它的峰值计算,其占地上部活植物生物量的９．６％,茎和枝占７０．４％。（３）地上部和地下部活植物生物量分别为１５５３ｇｍ－２和１４０８ｇｍ－２,其中桃金娘分别占８５％和８２％。（４）桃金娘叶子生物量在研究期间的波动较大,但没有以年为周期的季节变化。花和果的变化则较有规律,花蕾通常于３或４月开始形成,到７月底达到峰值,然后开始下降。（５）桃金娘的净生产量为８２０ｇｍ－２ａ－１,其中,花和果占１５．２％,茎和枝占１８．８％,根和叶分别占２１．３％和４３．７％。灌木林的净第一性生产量为１０１０ｇｍ－２ａ－１。（６）由于未考虑草食和根系的枯死损失,本研究所得的净第一性生产量（尤其是根的生产量）可能偏低。     

Effects of Climate Change and Shifts in Forest Composition on Forest Net Primary Production

Forests are dynamic in both structure and species composition, and these dynamics are strongly Influenced by climate.However, the net effects of future tree species composition on net primary production (NPP) are not well understood. The objective of this work was to model the potential range shifts of tree species (DISTRIB Model) and predict their impacts on NPP (PnET-Ⅱ Model) that will be associated with alterations in species composition. We selected four 200 × 200 km areas In Wisconsin, Maine, Arkansas, and the Ohio-West Virginia area, representing focal areas of potential species range shifts. PnET-Ⅱ model simulations were carried out assuming that all forests achieved steady state, of which the species compositions were predicted by DISTRIB model with no migration limitation. The total NPP under the current climate ranged from 552 to 908 g C/m2 per year. The effects of potential species redistributions on NPP were moderate (-12% to 8%) compared with the influence of future climatic changes (-60% to 25%). The direction and magnitude of climate change effects on NPP were largely dependent on the degree of warming and water balance. Thus, the magnitude of future climate change can affect the feedback system between the atmosphere and biosphere.     

我国不同季节陆地植被NPP对气候变化的响应

阐明不同季节陆地植被净第一性生产力(NPP)对全球变化的响应将有助于理解陆地生态系统和气候系统之间的相互作用以及NPP变化机制.本文使用1982～1999年间的AVHRR/NDVI、气温、降水以及太阳辐射等资料,结合植被分布图和土壤质地图,利用生态过程模型,研究不同季节我国陆地植被NPP的年际变化及其地理分异.结果表明,在1982～1999年的18年间,4个季节的NPP都呈显著增加趋势.其中,春季是NPP增加速率最快的季节,夏季是NPP增加量最大的季节.不同植被类型对全球变化的响应有很大差异.常绿阔叶林、常绿针叶林和落叶针叶林NPP的增加主要由生长季节的提前所致,而落叶阔叶林、针阔混交林、矮林灌丛、温带草原及草甸、稀树草原、高寒植被、荒漠以及人工植被NPP的增加主要来自生长季生长加速的贡献.从区域分布看,在四季中春季NPP增加量最大的地区主要集中在东部季风区域;夏季NPP增加量最大的地区包括西北干旱区域和青藏高原的大部分地区、小兴安岭-长白山区、三江平原、松辽平原、四川盆地、雷州半岛、长江中下游部分地区以及江南山地东部;而秋季植被NPP增加量最大的地区主要有云南高原-西藏东部和呼伦湖的周围等地区.不同植被和地理区域NPP的这些响应方式与区域气候特征及其变化趋势有关.     

Controls of Aboveground Net Primary Production in Mesic Savanna Grasslands: An Inter-Hemispheric Comparison

Patterns and controls of annual aboveground net primary productivity (ANPP) are fundamental metrics of ecosystem functioning. It is generally assumed, but rarely tested, that determinants of ANPP in one region within a biome will operate similarly throughout that biome, as long as physiognomy and climate are broadly consistent. We tested this assumption by quantifying ANPP responses to fire, grazing history, and nitrogen (N) addition in North American (NA) and South African (SA) savanna grasslands. We found that total ANPP responded in generally consistent ways to fire, grazing history, and N addition on both continents. Annual fire in both NA and SA consistently stimulated total ANPP (28–100%) relative to unburned treatments at sites with deep soils, and had no effect on ANPP in sites with shallow soils. Fire did not affect total ANPP in sites with a recent history of grazing, regardless of whether a single or a diverse suite of large herbivores was present. N addition interacted strongly and consistently with fire regime in both NA and SA. In annually burned sites that were not grazed, total ANPP was stimulated by N addition (29–39%), but there was no effect of N fertilization in the absence of fire. In contrast, responses in forb ANPP to fire and grazing were somewhat divergent across this biome. Annual fire in NA reduced forb ANPP, whereas grazing increased forb ANPP, but neither response was evident in SA. Thus, despite a consistent response in total ANPP, divergent responses in forb ANPP suggest that other aspects of community structure and ecosystem functioning differ in important ways between these mesic savanna grasslands.     

我国不同季节陆地植被NPP对气候变化的响应

阐明不同季节陆地植被净第一性生产力（NPP）对全球变化的响应将有助于理解陆地生态系统和气候系统之间的相互作用以及NPP变化机制。本文使用1982－1999年间的AVHRR／NDVI、气温、降水以及太阳辐射等资料,结合植被分布图和土壤质地图,利用生态过程模型,研究不同季节我国陆地植被NPP的年际变化及其地理分异。结果表明,在1982－1999年的18年间,4个季节的NPP都呈显著增加趋势。其中,春季是NPP增加速率最快的季节,夏季是NPP增加量最大的季节,不同植被类型对全球变化的响应有很大差异。常绿阔叶林,常绿针叶林和落叶针叶林NPP的增加主要由生长季节的提前所致。而落叶阔叶林、针阔混交林、矮林灌丛,温带草原及草甸,稀树草原、高寒植被,荒漠以及人工植被NPP的增加主要来自生长季生长加速的贡献。从区域分布看,在四季中春季NPP增加量最大的地区主要集中在东部季风区域;夏季NPP增量最大的地区包括西北干旱区域和青藏高原的大部分地区,小兴安岭－长白山区,三江平原,松辽平原,四川盆地,雷州半岛,长江中下游部分地区以及江南山地东部;而秋季植被NPP增加量最大的地区主要有云南高原－西藏东部和呼伦湖的周围等地区。不同植被和地理区域NPP的这些响应方式与区域气候特征及其变化趋势有关。