环境CO2浓度和群落密度对红桦(Betula albosinensis Burk.)幼苗碳氮吸收和分配的影响

当前大气CO2浓度升高是全球变化的主要趋势之一，CO2浓度升高还会引起全球变暖等其它环境问题，因而CO2浓度浓度升高对植物影响的研究已经成为全球变化领域的焦点。红桦是川西亚高山地区暗针叶林演替初期的先锋树种和演替后期的建群种，在群落演替过程中它对环境因子的响应决定红桦群落的演替进程。本文通过控制CO2浓度的气候室试验，研究了CO2浓度倍增环境下，不同密度水平红桦碳氮固定、分配可能发生的改变，并探讨了升高大气CO2浓度对群体内部竞争的影响。以期通过本研究明确川西亚高山地区代表性物种红桦对未来气候变化的响应，为今后采取措施应对气候变化、妥善进行森林管理提供理论依据和科学指导。主要研究结果如下： 1.升高CO2浓度对红桦幼苗生长的影响以及树皮、树干响应的不同 (1) CO2浓度升高显著促进红桦幼苗的生物量、株高、基茎的生长，同时也改变生物量在体内的分配格局，主要是增加根和主茎、减少叶在总生物量中的比重。(2)树皮和树干对升高CO2浓度的影响有差异，它们对CO2浓度升高的反应程度不同，但反应方向一致。 2.密度的副效应 (1) 增加种植密度对单株生物量、株高和基径的生长具有副效应，也降低升高CO2浓度对红桦生长的正效应。(2) 增加种植密度，显著增加红桦幼苗的群体生物量，从而使红桦群体固定更多的大气CO2气体。可见密度在决定红桦生物量及固碳能力方面具有重要意义。探索适合未来大气CO2浓度升高条件下植物生长的密度，对未来的森林经济生产、生态恢复具有重要意义。 3. 升高CO2浓度对红桦幼苗苗冠结构及冠层内部竞争的影响 (1) 冠幅、冠高、苗冠表面积和苗冠体积等树冠特征均受CO2浓度升高的影响而增加，但是受密度增加的影响而降低。(2) 单位苗冠投影面积叶片数(LDcpa)和单位苗冠体积叶片数(LDcv)均低于相应的现行CO2浓度处理，这主要是由于冠幅和冠高的快速生长所造成的。(3) LDcpa和LDcv的降低表明，红桦在升高CO2浓度的条件下，会作出积极的响应，从而缓解由于群体和个体生长的增加所引起的竞争压力的增加。 4. 升高CO2浓度对红桦幼苗养分元素吸收与分配的影响 (1) CO2浓度升高，植株各器官N、P含量降低，但单株N、P总吸收量均增加。红桦幼苗体内N、P浓度的下降是由于生物量迅速增加引起的稀释效应造成的。(2) CO2浓度升高，N、P向主茎和根的分配增加，向叶片的分配减少，主要是由于前者在总生物量中的比重增加，而后者减少了。(3) CO2浓度升高，氮磷利用效率(NUE和PUE)提高，氮磷累积速率(NAcR和PAcR)显著增加。而NUE和PUE的提高可以有效缓解CO2浓度升高后，亚高山和高山地区森林土壤中养分元素不足对森林生产力的限制。 5. 升高CO2浓度对红桦幼苗群体碳平衡的影响 (1) 升高CO2浓度对植物的光合作用、呼吸速率和生长均具有促进作用。(2) 土壤有机碳含量在实验前期迅速增加，后期积累速率下降。(3) 升高CO2浓度以后，土壤呼吸显著增强；土壤呼吸还具有明显的季节变化。(4) 红桦群体日固碳量受到升高CO2浓度的促进作用。结果(1)-(4)说明所研究群落的碳动态对现行的气候波动是敏感的；所研究群落在作为大气CO2气体的源-汇关系方面至少存在季节间的源汇飘移。(5)种植密度的升高显著增加了群体固碳量。 6. 升高CO2浓度对红桦幼苗生长后期叶片衰老的影响 升高CO2浓度有利于减缓红桦幼苗叶片生长季节末期的衰老。生长季节末期，随着CO2浓度的升高光合速率和可溶性蛋白含量均呈上升趋势，同时MDA（丙二醛）含量下降，保护酶SOD（超氧化物岐化酶）、CAT（过氧化氢酶）活性升高。由此说明，升高CO2浓度有利于减缓生长季节后期叶片的衰老，使叶片维持较高的光合速率，也从生理学的角度支持了本文及前人有关CO2浓度升高促进植物光合和生长的假说及结果。 The increased CO2 concentration is one of the most important problems among global changes. The increase of CO2 will also cause other environmental problems, such as global warming, etc. So the effects of elevated CO2 on plant have drawn sights of many scientists in the research field of global change. Red birch (Betula albosinensis) usually emerges as the pioneer species in initial stage and as constructive species in later stages of forest community succession of the dark coniferous forests in Western Sichuan, China. It’s response to elevated CO2 may determine the succession process of the community where it lives in. By controlling CO2 at the ambient and twice as the ambient level (ambient + 350 umol mol-1) using enclosed-top chambers (ETC), possible effects of elevated CO2 on carbon fixation and allocation under two plantation densities are investigated. The effects of elevated CO2 on competition within canopy of red birch seedlings are also observed in the present paper. We hope to make sure of the effects of elevated CO2 on the representative species, red birch. And so that, our results could provide a strong theoretical evidence and scientific direction for forest management and afforestation under a future, CO2 elevated world. The results are as fowllows: 1. The effects of elevated CO2 on growth and the different responses of wood and bark of red birch seedlings (1) Elevated CO2 increases the growth of seedling biomass, seedling height and basal diameter of red birch. It also changed the biomass allocation in red birch seedlings. The ratio of root and main stem to all biomass is increased and the ratio of leaf is decreased. (2) Tree bark and wood show different response degree but similar response direction to elevated CO2. 2. Negative effects of planting density (1) The increase of planting density showes negative effects on the individual growth of seedling biomass, seedling height and basal diameter of red birch. It also eliminates the positive effects of elevated CO2 on growth of red birch seedlings. (2) Community biomass is increased by the elevated planting density, which means that the high density red birch community could fix more CO2 than the low density one. These results show that planting density plays an important role in determining biomass and carbon fixation ability of red birch community. Thus, exploring proper planting density becomes economically important for the future, CO2 elevated word. 3. The effects of elevated CO2 on crown architecture and competition within canopy of red birch seedlings (1) Crown width, crown depth, crown surface area and crown volume are all increased under the influence of elevated CO2. (2) Leaf number per unit area of projected crown area (LDcpa) and per unit volume of crown volume (LDcv) are lower under elevated CO2. This is resulted from the stimulated growth of tree crown features. (3) The decrease of LDcpa and LDcv indicate that plants will respond forwardly to reduce the possible increase of competition resulted from stimulated growth of individual plant and collectives in conditions of elevated CO2. 4. The effects of elevated CO2 on nutrition accumulation and allocation of red birch seedlings (1) Contents of N and P decrease due to the prompt increase of biomass of plant organs caused by elevated CO2. However, their accumulations increase under elevated CO2. (2) Elevated CO2 increases the allocation of N, P to main stem but reduced its allocation to leaf for that dry weight of the former increased but the dry weight of the later decreased. (3) Using efficiencies of N, P (NUE and PUE) and their accumulation rates (NAcR and PAcR) are found to increase under elevated CO2. Soil nutrition contents are always the limiting factors for plant growth at subalpine and alpine region. The increased NUE and PUE are helpful to eliminate the nutrition limitation in this area in the future world, when CO2 concentration doubles the ambient. 5. The effects of elevated CO2 on carbon balance of red birch communities (1) Net photosynthetic rates (Pn), dark respiration rates (Rd) and growth are all stimulated by elevated CO2. (2) Content soil organic carbon increases sharply at the primary stage of experiments and then the increasing rates decrease to a low level at later stages. (3) Soil respiration rates increase significantly with the elevation of CO2 concentration. (4) The daily carbon fixations of whole community are heightened by elevated CO2. The results (1)-(4) suggest that, the community being studied are sensitive to current climate change; the studied community, as a sink of atmospheric CO2, is pool-sink alternative between seasons. (5) The carbon fixations are increased along the increase of planting densities. 6. The effects of elevated CO2 on physiological features of leaf senescences of red birch seedlings at the later stage of growing season Elevated CO2 helps to postpone the leaf senescences of red birch at the end of the growth season. CO2 enrichment increases the photosynthetic rates, contents of soluble proteins and photosynthetic pigments. And meanwhile contents of malondialdehyde (MDA) decreases and activities of superoxide dismutase (SOD) and catalase (CAT) are both increased. These results suggest that the senescences of red birch leaves are delayed by elevated CO2, which keep the photosynthetic rates at relatively high levels. Our results lend supports to hypothesis and results on stimulated photosynthetic rates and growth from both other researchers and the present paper.

CO2浓度升高对红桦幼苗生理与生长的影响

大气CO2浓度的增加已经成为不可争议的事实。预计本世纪末大气CO2浓度将增加到约700µmol mol-1。森林年光合产量约占陆地生态系统年光合产量的70%。森林树木是一个巨大的生物碳库，约占全球陆地生物碳库的85%。森林树木对CO2的固定潜力是缓解由大气CO2浓度升高引起的未来全球气候变化问题的决定性因子之一。红桦（Betula albosinensis Burk.）是川西亚高山采伐迹地自然或人工恢复的重要树种。本研究以1a红桦幼苗为模式植物，采用人工模拟的方法，研究CO2浓度升高对不同种内竞争强度（种群水平）下红桦幼苗的生理特征、生长、干物质积累及其分配的影响，探讨在种内竞争生长条件下红桦幼苗的“光合适应机理”与生长特征，为西南亚高山森林生产力对未来全球变化的预测提供重要参考。 本研究的主要结果如下： 1）在种内竞争生长条件下红桦幼苗经过CO2浓度升高熏蒸4个月后，叶片出现“光合适应”现象。与对照相比，低种植密度（28株m-2）和高种植密度（84株m-2）条件下的红桦幼苗净光合速率（A）、气孔导度（gs）、蒸腾速率（E）、表观量子产量（AQY）和羧化速率（CE）显著降低，而水分利用效率（WUE）则显著提高。CO2浓度升高处理的红桦幼苗叶片Rubisco活性、单位叶面积N浓度、叶绿素a、叶绿素b和类胡萝卜素浓度都显著降低。但CO2浓度对红桦幼苗的叶绿素a与叶绿素b的比值没有显著影响。CO2浓度升高显著增加红桦幼苗单位叶面积的非结构性碳水化合物（TNC）浓度，结果是红桦幼苗的比叶面积（SLA，cm2 g-1）显著降低。 2）与对照相比，CO2浓度升高处理的红桦幼苗高、基径、单叶面积和侧枝的相对生长速率（R GR）显著提高，尤其在试验处理的早期。CO2浓度升高既增加单株红桦幼苗总叶片数量又增加单叶面积，结果是单株红桦幼苗的总叶面积比对照显著增加。 3）CO2浓度升高处理显著增加红桦幼苗干物质积累（尤其是细根生物量），改变了红桦幼苗生物量的分配格局。与对照相比，CO2浓度升高处理的红桦幼苗叶重比（LWR）、叶面积比（LAR）、叶根重比（Wl/Wr）和源汇重比（leaf weight to non-leaf weight ratio, Wsource/Wsink）显著下降（高种植密度的LWR除外），而根冠比（R/S）则显著增加。在两种种植密度条件下，CO2浓度升高显著增加红桦幼苗根生物量的分配比率，显著降低叶片的生物量分配比率，对主茎、侧枝以及地上生物量的分配比率不变或约有下降。 总之，长期生长在CO2浓度升高条件下的红桦幼苗光合能力下降，并伴随Rubisco活性、叶N浓度、光合色素浓度的显著降低以及TNC浓度的显著增加。支持树木光合速率下降与Rubisco活性、叶N浓度下降以及TNC浓度增加紧密相关的假设。CO2浓度升高处理红桦幼苗的早期相对生长速率大大高于对照，而后期迅速下降，说明红桦幼苗生物量的显著增加主要归功于CO2浓度升高的早期促进作用和叶面积的显著增加。CO2浓度升高显著增加红桦幼苗根系生物量和根冠比，表明红桦幼苗“额外”固定的C向根系转移。 The steady increae of atmospheric CO2 concentration（[CO2]）has been inevitable fact. Models predict that the atmospheric [CO2] will increase to about 700µmol mol-1 at the end of the twenty-first century. As trees constitute a majoor carbon reservoir–85% of total plant carbon is found in forest, and their ability to sequester carbon is a key determinant of future global change problems caused by increases in atmospheric CO2. In addition to the role of forests in the global carbon cycle, inceased growth could be of economic benefit, for example, offsetting deleterious effects of climatic changes. Betula albosinensis (Burk.) usually emerges as the pioneer species in initial stage and as constructive species in later stages of forest community succession of mountain forest area, and also is one of important tree species for afforestation in logged area, in southwesten China. In this experinment, Betula albosinensis seedling (one-year-old) was used as the model plant. B. albosinensis seedlings were grown under two all-day [CO2], ambient (about 350 µmol·mol-1) and elevated [CO2] (about 700 µmol·mol-1), and two planting densities of 28 plants per m2 and 84 plants per m2. The objectives were to characterize birch mature leaf photosynthesis, growth, mass accumulation and allocation responses to long-tern elevated growth [CO2] under the influences of neighbouring plants, and to assess whether elevated [CO2] regulated birch mature leaf photosynthetic capacity, in terms of leaf nitrogen concentration (leaf [N]), activity of ribulose bisphosphate carboxygenase (Rubisco), Rubisco photosynthetic efficiency, and total nonstructural carbohydrates (TNC) concentration, and also to provide a strong reference to predict the productivity of subalpine forests under the future global changes. The results are as follows: 1) B.albosinensis seedlings exposed to elevated [CO2] for 120 days, photosynthetic acclimation phenomena occurred. At two planting densities, leaves of birch seedlings grown under elevated [CO2] had lower net photosynthetic rate (A), stomatal conductance (gs), transpiration (E), apparent quantum yield (AQY) and carboxylated efficiency (CE) and higher water use efficiency (WUE), compared to those of B.albosinensis seedlings grown under ambient [CO2]. Based on the leaf area, leaf [N], Rubisco activity and photosynthetic pigments concentrations of B. albosinensis seedlings grown under elevated [CO2] were significantly lower than those grown under ambient [CO2]. The ratio of chlorophyll a to chlorophyll b concentration was not affected by elevated [CO2]. Under elevated [CO2], the TNC concentration per unit leaf area significantly increased, resulting in significant decrease in specific leaf area. Thus leaf photosynthetic capacity of B. albosinensis seedlings would perform worse under rising atmospheric [CO2] and the influences of neighbouring plants. 2) Under elevated [CO2], the relative growth rate (RGR) of B. albosinensis seedlings height, basal diameter, a leaf area and branch length significantly increased, especially at the initial stage of exposure to elevated [CO2], and a leaf area and leaf numbers per B. albosinensis seedling also significantly increased. Thus the total leaf area per B. albosinensis seedling was significantly increased under elevated [CO2]. 3) As the increase of RGR and total leaf area, biomass of B. albosinensis seedling grown elevated [CO2] was higher, compared to that of B.albosinensis seedlings grown at ambient [CO2]. Elevated [CO2] changed the biomass allocation pattern of B. albosinensis seedling. At two planting densities, B. albosinensis seedlings grown elevated [CO2] had lower leaf weight to total weight ratio (LWR), leaf area to total weight ratio (LAR) and leaf weight to non-leaf weight ratio (Wsource/Wsink), but higher root weight to shoot weight ratio (R/S), compared to those of B.albosinensis seedlings grown at ambient [CO2]. Under elevated [CO2], roots biomass to total biomass ratio was signigicantly increased, leaves biomass to total biomass ratio was significantly decreased. The main stem and branch biomass to total biomass ratio were not affected by elevated [CO2]. In conclusion, our results supported the hypothesis that the decline in photosynthetic capacity of C3 plants will appear after long-term exposure to elevated [CO2], accompanying with the significant decrease in Rubisco activity, leaf N concentration, photosynthetic pigments concentration, and significant increase in total non-structural carbohydrates concentration. Our results also have shown that the increase of biomass of B. albosinensis seedlings should be attributed to initial stimulation on RGR and total leaf area resulted from elevated [CO2]. Under elevated [CO2], the extra carbon sequestered by B.albosinensis seedlings transferred into under-ground part because of increase in root biomass and R/S.

土壤微生物和酶对大气CO2浓度与温度升高的响应

土壤微生物(Soil microbes)是生态系统的重要组成部分，它参与土壤中复杂有机物质的分解和再合成，也参与C、N、S、P等的循环。土壤酶(Soil enzyme)是土壤中具有生物活性的蛋白质，它与微生物一起推动着土壤的生物化学过程，并在树木营养物质的转化中起着重要的作用。鉴于土壤微生物和土壤酶对环境变化的敏感性，它们在CO2浓度和温度升高时的反应将在很大程度上影响森林生态系统的结构和功能。因此，要全面评价大气CO2浓度和温度升高对整个生态系统的影响，有必要对CO2浓度和温度升高条件下的土壤微生物的反应进行深入的研究与探讨。本文应用自控、封闭、独立的生长室系统，研究了川西亚高山岷江冷杉（Abies faxoniana）根际、非根际土壤微生物数量，红桦（Betula albosinensis）根际微生物数量以及根际、非根际土壤酶活性对大气CO2浓度(环境CO2浓度+350±25μmol·mol-1，EC)和温度(环境温度+2.0±0.5℃，ET)升高及两者同时升高(ECT)的响应。结果表明： 1) EC和ET显著增加岷江冷杉根际微生物数量，但不同微生物种类对EC和ET的反应有所差异。6、8和10月，岷江冷杉根际微生物数量与对照(CK)相比，EC处理的根际细菌数量分别增加了35%、164%和312%，ET处理增加了30%、115%和209%；EC和ET处理对根际放线菌和根际真菌数量影响不显著。ECT处理的根际放线菌数量分别增加了49%、50%和96%，根际真菌数量增加了151%、57%和48%；而ECT对根际细菌数量影响不显著。EC、ET和ECT处理对岷江冷杉土壤微生物总数的根际效应明显，其R/S值分别为1.93、1.37和1.46(CK的R/S值为0.81)。 2) 红桦根际微生物数量对EC、ET和ECT的响应不同。生长季节(5~10月)，高密度的红桦根际细菌数量与CK 相比，EC的根际细菌数量分别增加28%、33%、423%、65%、43%和79%，而低密度的红桦根际细菌数量增加不显著。ET能显著增加根际细菌数量(7~10月)，其中高密度的根际细菌数量分别增加了377%、107%、35%、22%，而低密度的根际细菌数量分别增加了27%、27%、64%、48%；ECT对两个密度水平下根际细菌数量均未产生有显著的影响。高、低密度的红桦根际放线菌和根际真菌数量与 CK 相比，EC显著增加了低密度的红桦根际放线菌数量，而对高密度的根际放线菌数量无显著影响；ET和ECT对高低密度的红桦根际放线菌数量均未产生显著影响。EC和ET对高低密度的根际真菌数量也无显著影响，而ECT却显著增加了高低密度的根际真菌数量。 3) EC、ET和ECT处理的低密度红桦根际微生物(细菌、放线菌和真菌)数量没有显著高于或低于高密度根际微生物数量，表明短期内密度对红桦根际微生物数量不产生影响。 4) 不同种类的氧化还原酶对EC、ET和ECT的响应不同。5~10月，EC的红桦根际过氧化氢酶活性是CK 的1.44、1.06、1.11、1.10、1.12和1.24倍，差异显著(6月除外)；ET和ECT处理根际过氧化氢酶活性无显著增加。EC的红桦根际多酚氧化酶活性比CK显著增加；ET的根际多酚氧化酶活性显著高于CK(8月除外)。ECT的根际多酚氧化酶活性高于CK，差异不显著。EC的根际脱氢酶活性分别增加了46%、40%、133%、48%、17%和26%，差异显著。5~7月，ET和ECT的根际脱氢酶活性高于CK的脱氢酶活性，而8~9月则相反，差异性均不显著。 5) EC、ET和ECT对不同种类的水解酶的影响不同。EC能显著增加红桦根际脲酶活性，5~10月分别增加了29%、42%，、70%、67%、59%和57%。ET和ECT 对根际脲酶活性未产生显著影响。EC显著提高根际转化酶活性，5、6和9月EC的根际转化酶活性分别比CK高51%、42%和40%。5和10月，ET的根际转化酶活性低于CK，而其余月份却高于CK，但均具有显著性差异。ECT的根际转化酶活性与CK的根际转化酶活性有显著性差异(9月除外)，5、6和7月的根际转化酶活性分别提高了94%、198%和67%。 6) 与CK相比，EC、ET和ECT的非根际土壤微生物数量以及非根际土壤酶活性均无显著提高。EC、ET和ECT的过氧化氢酶、脲酶的根际效应明显，而多酚氧化酶和脱氢酶根际效应不明显。EC和ECT的转化酶根际效应明显，而ET的转化酶根际效应不明显。 It is well known that atmospheric CO2 concentration and temperature are increasing as a consequence of human activities. In past decades, considerable efforts had been put into investigating the effects of climate change on processes of forest ecological system. In general, studies had been mainly focused on the effects of elevated atmospheric CO2 on plant physiology and development, litter quality, and soil microorganisms. Studies showed that there was variation in the responses of root development and below-ground processes to climate between different plant communities. Since the concentration of CO2 in soil was much higher (10~50 times) than in the atmosphere, increasing levels of atmospheric CO2 may not directly in fluence below ground processes. Betula albosinensis and Abies faxoniana, as the dominated tree species of subalpine dark coniferous forest in the western Sichuan province, which play an important role in the structure and function of this kind of forest ecosystem. In our study, effects of elevated atmospheric CO2 concentration (350±25μmol·mol-1), increased temperature (2.0±0.5℃) and both of the two on the number of rhizospheric microbe and rhizospheric enzyme activity were studied by the independent and enclosed-top chamber’ system under high-frigid conditions. Responses of rhizospheric bacteria, actinomycetes and fungi number of Betula albosinensis and Abies faxoniana under different densities(high density with 84 stems·m-2, low density with 28 stems·m-2 ), and rhizospheric enzyme activity of Betula albo-sinensis to elevated CO2 concentration and increased temperature were analyzed and discussed. The results are as the following, 1) In comparion with the control, the numbers of rhizospheric bacteria of Abies faxoniana were increased by 35%, 164% and 312% significantly in June, August and October respectively of EC, and were increased by 30%, 115% and 209% respectively of ET.However the effect of EC and ET on rhizospheric actinomycetes and fungi was not significant. The number of rhizospheric actinomycetes of ECT were increased significantly by 49%, 50% and 96% respectively, and the increment of rhizospheric fungi were 151%, 57% and 48% respectively .The effect of ECT on rhizospheric bacteria was not significant. Rhizospheric effect of soil microbe for all treatments was significant, with the R/S of 1.93, 1.27 and 1.46 for EC, ET and ECT, respectively. 2) Treatment EC improved the number of rhizospheric bacteria of Betula albosinensis under high density significantly in comparison with the control, over the growing season, the greatest increment of rhizospheric bacteria was from July. However, EC had no effect on the number of rhizospheric bacteria under low density. Except May and June, treatment ET improved the number of rhizospheric signifcantly. The effect of treatment ECT on the number of rhizospheric bacteria under different densities was not significant. Of treatment EC, the number of rhizospheric actinomycetes of Betula albosinensis under low density were increased significantly, however, treatment EC did not stimulate the number of rhizospheric actinomycetes under high density. Simultaneously, treatment ET and ECT did not stimulate the number of rhizospheric actinomycetes. Finally, in treatment ECT, the number of rhizospheric fungi under high density were increased significantly, however treatment EC and ET did not stimulate the number of rhizospheric fungi under different densities. 3) Of treatment EC, ET and ECT, the number of rhizospheric microbe of Betula albosinensis under low density were not more or fewer than that of microbe under hign density along the growing season, which showed that plant density had no effect on the nmber of microbe. 4) From May to October, 2004，rhizospheric catalase activity of Betula albosinensis of treatment EC was 1.44, 1.06, 1.11, 1.10, 1.12 and 1.24 times as treatment CK respectively, and the difference was statistically significant(except June). Treatment ET and ECT did not increase rhizospheric catalase activity significantly. In treatment EC, the rhizospheric pohyphenol oxidase activity was higher than treatment CK significantly. The rhizospheric pohyphenol oxidase activity of treatment ET was higher than CK significantly (except August). The rhizospheric pohyphenol oxidase activity of treatment ECT was higher than CK, but the difference was not statistically significant. Over the growing period, the rhizospheric dehydrogenase activity were increased 46%, 40%, 133%, 48%, 17% and 26% respectively by treatment EC, and the difference was statistically significant. From May to July, the rhizospheric dehydrogenase activity in treatment ET and ECT was higher than CK, but from August to October, the rhizospheric dehydrogenase activity was lower than CK, the difference was not significant. 5) Treatment EC increased rhizospheric urease activity significantly, from May to October, rhizospheric urease activity were increased 29%, 42%, 70%, 67%, 59% and 57% respectively by EC. Treatment ET and ECT had no effect on rhizospheric urease activity. Treatment EC improved rhizospheric invertase activity significantly, in May, June and September, the rhizospheric invertase activity of treatment EC were increased 51%, 42% and 40% in comparison with the control. Except May and October, the rhizospheric invertase activity of treatment ET was markly higher than CK. The rhizospheric invertase activity of treatment ECT was significantly different from CK (except September), in May, June and July treatment ECT increased rhizospheric invertase activity by 94%, 198% and 67% respectively. 6) In comparison with the control, treatment EC, ET, and ECT had no effect on the number of non-rhizospheric microbe and non-rhizospheric enzyme activity. Rhizospheric effect of catalase and urease for all treatments was significant, but rhizospheric effect of pohyphenol oxidase and dehydrogenase was not significant. Rhizospheric effect of invertase of EC and ECT was significant, but rhizospheric effect of invertase of ET was not significant.

大气CO2浓度升高对红桦碳水化合物含量和分配的影响

碳水化合物按其存在的形式可分为结构性碳水化合物和非结构性碳水化合物两种。前者主要用于植物体的形态建成；后者是参与植物生命代谢的重要物质。迄今为止，有关CO2浓度升高对植物叶片中的碳水化合物含量的研究较多，而对其它器官中碳水化合物含量以及碳水化合物在植物体内的分配响应研究较少。碳水化合物含量在植物各器官中的变化能够反映光合同化产物在叶和茎、枝和根中的转运情况；碳水化合物的分配与植物的生长模式相关，它的变化会对植物的生长情况产生影响。因此，为全面认识植物生理生化与生长过程对大气CO2浓度升高响应情况，需要对CO2浓度升高条件下植物体内碳水化合物的含量及分配变化进行深入的研究与探讨。本文应用自控、独立、封闭的生长室系统，研究了红桦幼苗根、茎、叶和枝的碳水化合物含量以及分配格局对大气CO2浓度升高(环境CO2浓度+350 µmol·mol-1) 的响应。研究结果表明：1) CO2浓度升高使红桦幼苗叶片中的非结构性碳水化合物含量显著增加。这可能会对光合作用造成反馈抑制，降低光合速率。2) CO2浓度升高使红桦幼苗根、茎和枝中的还原糖、蔗糖、总可溶性糖、淀粉和总的非结构性碳水化合物(TNC) 含量显著增加。说明CO2浓度升高促进了碳水化合物由叶片向枝、茎和根中的运输转移，支持了Finn和Brun的假设。3) 在总的非结构性碳水化合物(TNC) 中，淀粉所占比例最大。同样地，CO2浓度升高使TNC含量增加的部分中，淀粉所占的比例也最大。在叶片、枝、茎和根中淀粉含量增加部分占TNC含量增加部分的91.45%、88.23%、83.23%和82.01%。4) CO2浓度升高使红桦幼苗根、茎、叶和枝内的纤维素含量有增加的趋势，但未达到显著水平。需要进一步研究长期CO2浓度升高下，纤维素含量的响应程度。5) CO2浓度升高使碳水化合物在红桦幼苗体内的分配发生了改变。红桦幼苗体内碳水化合物分配变化的一致趋势是由地上部分向地下部分分配转移。其中，测定的所有碳水化合物均向根中分配增多。同时，CO2浓度升高使红桦幼苗的根冠比显著增大；根系干重显著增加。这些结果支持了Gorissen 和Cotrufo的假设，即碳水化合物向根中分配增多是根冠比增大的主要原因。6) CO2浓度升高使红桦幼苗体内的氮含量显著下降。氮含量的下降可能主要是由生长的加快和TNC (主要是淀粉) 含量的增加对氮的稀释造成的。Carbohydrates found in plants are frequently grouped into two different classes:structural carbohydrates and non-structural carbohydrates. The former mainlyconstruct the plant basic framework, while the latter are essential for plant growth andmetabolism. As yet there is lack of information on the effects of elevated CO2concentration on carbohydrate contents in stem, branch and root of plant, and oncarbohydrate allocation in organs of plant although there have been many reports onthe responses of carbohydrate contents to elevated CO2 concentration in plant foliages.A shift of carbohydrate contents in plant reflects a change in transporting ofphotosynthetic production from leaf to stem, branch and root of plant. The allocationof carbohydrates that is correlated to plant growth patterns affects plant growth. Thus,in order to understand the influences of elevated CO2 on biochemical process,physiological change and plant growth well, the response of carbohydrate contentsand allocation in plant to elevated CO2 should be further investigated. In our study, theeffects of elevated CO2 on carbohydrate contents and their allocation between leaf,stem, branch and root tissue of Betula albosinensis seedlings were determined. Theseedlings were grown in independent and enclosed-top chambers. Chambers werecontrolled to reproduce ambient (CK) and ambient + 350 µmol·mol-1 CO2 (EC)concentration for 1 year. The results here showed that,1) Elevated CO2 significantly increased non-structural carbohydrate contents in leafof red birch seedlings. This will reduce photosynthetic rate.2) Elevated CO2 also significantly increased non-structural carbohydrate contentsin root, stem and branch of red birch seedlings. These findings supported thehypothesis that elevated CO2 accelerated carbohydrates from leaf to branch, stem androot.3) Starch makes up the largest parts of total non-structural carbohydrate. In thesame way, the increase of starch plays a main role in the increase of totalnon-structural carbohydrate under elevated CO2. In leaf, branch, stem and root, theincrements of starch contents comprised 91.45%, 88.23%, 83.23% and 82.01% of theincrements of total non-structural carbohydrate contents.4) Under elevated CO2 the cellulose contents have an increasing tendency in redbirch seedlings. It is needed to investigate the effects of long-term elevated CO2 oncellulose contents in plant.5) There are significant CO2 effects on the allocation of carbohydrate in organs ofred birch seedlings. Under elevated CO2 more carbohydrates were allocated to root.Moreover, CO2 enrichment significantly increased the root to shoot ratio of red birchseedlings and the dry weight of roots. These results supported Gorissen and Cotrufo ‘shypothesis that increase of carbohydrate allocation to root mostly contributed to theincrease of root to shoot ratio.6) Elevated CO2 brought about a reduction in the nitrogen contents of leaf, stem,branch and root. The decline of nitrogen contents under elevated CO2 is mainlycaused by the dilution effects of increasing starch level and growth of red birchseedlings.

桦木科植物的系统发育和地理分布

本文对桦木科植物的研究历史作了详细的总结;在钻研文献的基础上，补充了部分系统学资料，使得花序、花、花粉、叶表皮等各类性状能够在属间进行比较，根据外类群比较、和谐性分析等原则确定了性状的演化极性，利用最大同步法和最小平行演化法对桦木科植物进行了分支分析;对各属的现代分布和地史分布作了描述，在此基础上，讨论了桦木科植物的分布中心、起源地、起源的时间和散布的途径;在第四章，作者试图回到遥远的晚白垩纪和早第三纪，从描绘桦木科植物起源和早期分化的古地理和古气候背景入手，分析了在这种背景下桦木科植物所发生的空间辐射以及植物体本身所产生的形态进化，以求得对桦木科植物起源、散布和分化作出比较合理的解释;最后对桦木科组以上的等级作了分类处理。全文包括五个部分，主要的结论如下： 1、分支分析：广泛阅读桦木科、壳斗科和南青冈科的文献，详细研究中国科学院植物研究所标本馆所藏的桦木科植物的标本。首先以壳斗科和南青冈科作为外类群对各类性状进行了分析，得到一个由22个性状组成的数值矩阵;接着又对上述的22个性状作了和谐性分析，结果有7个性状的CN>O,2，其中3个性状在调整性状状态后被保留，有4个性状在颠倒极性和调整性状状态后仍不和谐被去除．最后得到由18个性状组成的矩阵，该矩阵和谐性检验的结果是：所有性状的KN值和CN值均为O，将此矩阵用最大同步法和最小平行演化法进行分支分析，得到一个相同的分支图。分支图用了19个演化步数，与矩阵的最小步数相同，较好地反映了桦木科植物的属间关系。分支图说明：桤木属是从桦木科植物的祖先中最早分出的一个分支，几乎保留了祖先所有的原始性状;桦木属和桤木属近缘，但并非姊妹群;榛届在桦木科中占有特殊的地位，是桦木科植物的原始类群向进化类群演化的中间纽带;虎棒子属是榛属向鹅耳枥属和铁木属进化过程中分化出的一支;铁木属和鹅耳枥属为姊妹群，在桦木科植物中演化水平最高。 2、地理分布：地理分布分析是以经典分类、系统发育和古植物学三方面的资料为基础，根据生物进化的时、序、空相互统一的观点来讨论的。 根据Takhtajan (1978)对世界植物系的分区，认为：东亚区分布6属、13组、77种，占桦木科植物全部种类的59%，为第一分布中心;大西洋一一北美区分布5属。8组、20种，为第二分布中心;环北方区分布5属、8组，35种，是桦木科植物分化的重要地区。在中国，根据吴征镒(1979)对中国植物区系的分区，认为：中国一一日本森林亚区和中国一一喜马拉雅亚区在种数，组数和属数的分布上分别位居第一和第二。四川及其毗邻省区分布6属、52种，占全部中国种类的70, 3%，是中国桦木科植物的分布中心。 桦木科最早的化石记录是具多个角萌发孔并有带状加厚的桤木粉，发现于日本桑托期．随之这类花粉和另外一种花粉类型：副桤木粉（有微弱带状加厚的三孔粉）在欧亚大陆和北美的地层中便开始普遍起来;可能的桤木属植物的叶子发现于白垩纪最晚期，而可辨认的果序的记录则开始于古新世． 8孔的具带状加厚的桦粉最早见于日本的坎佩尼期，而缺少带状加厚的拟桦粉最早发现于中国内蒙古的梅斯特利克蒂期，以上两类花粉均和现代桦木属植物的花粉相似;可归于同一个化石植物Betula leopoldae的叶子、雄花序，果序和果实的化石发现于加拿大大不列颠哥伦比亚的中始新世地层中。基于果实化石的榛属植物的最早记录发生在欧洲和北美古新世;被认为和榛属有亲缘关系的绝灭属——古鹅耳枥属的叶子，果序和雄花序的化石发现于古新世和始新世;开始见于中国梅斯特利克蒂期的拟榇粉和最早发现于苏格兰古新世的米勒三孔粉也均和榛属植物有关。基于可辨认的花粉和果苞的化石，鹅耳枥属和铁木属分别在晚始新世和早渐新世有了最早的化石记录． 最后根据化石证据和现代地理分布特征提出：以四川为中心的中国中部地区是桦木科植物起源和早期分化的中心;最早的桦木科植物生活在晚白垩纪桑托期，桤木属、榇属、桦木属可能在白垩纪最晚期或古新世时就已经出现了，而最迟不晚于中始新世;鹅耳枥属和铁木属的形成均不晚于晚始新世，到渐新世时，除虎榛子属外，桦木科其它各属均广泛分布在北半球。 3、进化分析：桦木科植物起源和早期演化的晚白垩纪和早第三纪在古地理和古环境方面主要有四个特点：(1)地球板块相对稳定;(2)气候相对一致，区带环流是大气环流的基本成份; (3)恐龙绝灭，哺乳动物作为传播媒介变得重要起来; (4)风媒和虫媒植物共荣。桦木科植物就是在上述背景下起源的。桤木属蒙自桤木组和桤木组最早从祖先类群中分化出来，接着一方面较缓慢地向欧洲散布，并在古新世到达欧洲;另一方面，向中国东北地区散布，然后迅速地扩散到了北极地区，通过白令陆桥在白垩纪最晚期到达了北美。从北美西北部和从欧洲通过大西洋北极陆桥散布到北美东部的桦木科植物在始新世时汇合，形成第二个分化中心。虎榛子属、鹅耳枥属和铁木属植物的大量分化很可能是从全球气候恶化的渐新世开始的，并在分化的同时伴随着其它的桦木科植物向南迁移。桤木属在渐新世时就散布到了当时位于中国东南部的加里曼丹岛;桤木属、鹅耳枥属和铁木属中新世时散布到了墨西哥和中美洲;第四纪冰期加速了桦木科植物的南移，桤木属到达非洲北部和南美洲，桤木属和鹅耳枥属到达台湾岛均发生在更新世。 在环境的选择压力下，桦木科植物经历了一系列的形态演化，作者将这些演化归纳成34个进化趋势。为了对桦木科植物可能祖先的大概轮廓有一个认识，我们又从34个进化趋势中总结出桦木科植物的11个原始特征，并且认为这些特征中的大多数应该是它的祖先拥有的。 (1)裸芽有柄。 (2)气孔器为轮列型或无规则型。 (3)木材具管胞，导管有螺旋加厚，为梯状穿孔。 (4)雌、雄花序共生成总状花序，雄花序位于上部。 (5)花序两性。 (6)雄花序有梗、裸露过冬。 (7)小聚伞花序由多个花组成，苞片多数。 (8)花两性，有花被，子房3室。 (9)花药药室木分离，花丝也不分叉。 (10)花粉粒4-5孔;孔具孔室;孔间有带状加厚;外壁较厚，在孔处翘起并加厚。 (11)具翅坚果小型。 本文提出桦术科植物不可能起源于现存的壳斗科植物，而两者有可能共祖，它们共同的祖先和正型粉类复合群有关，可能来源于正型粉类复合群的某些成员，那么‘正型粉类复合群是否就是金缕梅目和壳斗目进行的中间链环呢?’本文仅作为一个问题提出，而未作回答。 4、系统分类：根据分支分析和表征分类的结果，桦木科是非常自然的一个类群，科内表现出从原始到高级的演化次序并具有三条主要的演化路线。因此，将桦木科划分为三个族与科内的三条演化线相一致，比较符合其属间的系统发育关系。按照各属的变异程度，进一步在桦木族和鹅耳枥族之下分别设立两个亚族。此外在桦木科植物属之下共确立了13个组。桦木科组以上的系统排列为： Betulaceae S. F. Gray Trib. 1. Betuleae Subtrib. 1. Alninae Z. D. Chen subtrib. nov. Alnus Mill. Sect. 1. Clethropsis ( Spach ) Endl. Sect. 2. Alnus Sect. 3. Cremastogyne H. Winkl, Sect. 4. Alnobetula W. D. Koch Subtrib. 2. Betulinae Betula L. Sect. 1. Betulaster ( Spach ) Regel Sect. 2. Betula Sect. 3. Costatae Regel Sect. 4. Chinenses ( Nakai ) Z. D. Chen comb. et stat.nov. Sect. 5. Humiles W.D.Koch Trib. 2. Coryleae Aacheraon Corylus L. Sect. 1, Acanthochlamys Spach Sect. 2. Corylus Trib. 3. Carpineae A. DC. Subtrib. 1. Ostryopsinae Z. D. Chen subtrib. nov.Ostryopsis Dence. Subtrib. 2. Carpininae Ostrya Scop. Carpinus L. Sect. 1. Distegocarpus ( Sieb. et Zucc. ) Sarg. Sect. 2. Carpinus

黑龙江嘉荫地区古新世孢粉植物群及古植被、古气候研究

植物是环境变化的重要指示物之一。晚白垩至早第三纪时期，全球生态系统发生了剧烈变化，研究这一时期植物对了解地质历史时期环境变化趋势, 认识和保护当今环境有重要意义。我国黑龙江省嘉荫县有这一时期的地层发育，其中乌云煤矿和白山头是主要的露头剖面。前人曾从地质时代、孢粉及植物化石角度对这两个剖面进行过研究，但是仍有部分问题尚存争议。在本项工作中，我们对两个剖面的孢粉样品进行了系统采样，部分孢粉类型同时在光镜和电镜下进行了拍照。我们还对存在争议的这两个剖面的地质时代进行了讨论。同时，首次用共存分析法对这两个剖面的在沉积时期的气候进行了整体及分段的定量重建。另外，我们结合中其它地点的气候重建工作对不同时期的纬度温度梯度进行了研究。 乌云煤矿和白山头两个乌云组剖面的古新世孢粉植物群的研究结果表明：乌云煤矿孢粉植物群主要是与榛属（Corylus），桤木属（Alnus），桦木属（Betula），榆属（Ulmus）及松属（Pinus）有亲缘关系的植物；白山头剖面的孢粉植物类型与乌云煤矿基本一致，但是其中针叶类植物的花粉所占比重较大。 根据乌云煤矿与白山头剖面的孢粉类型在地层中的分布，以及与其它古新世地层的对比，我们认为乌云煤矿与白山头含孢粉段的地质时代为古新世。 用共存分析法得到乌云组古新世气候参数有两组。孢粉类型的共存结果为：年均温14.8-14.9℃，年降水量816-1389mm；植物化石类型的共存结果为：年均温16.3-16.8℃, 年降水：1124-1623mm。对乌云煤矿与白山头两个剖面孢粉带中的孢粉类型的气候参数分别进行共存，结果表明，除乌云煤矿孢粉第三带到第四带外，乌云地区的年均温在整个沉积时期均呈上升趋势；年均降水量的变化趋势与年均温基本一致。 根据从古新世到现代不同地点气候定量重建的年均温参数，我们计算得到了不同时期纬度温度梯度变化的值：<0.1℃/古纬度（古新世）、 0.1℃/古纬度（始新世）、0.45℃/纬度（中新世）、0.55℃/纬度（上新世）。结合当今全球的平均温度梯度值（0.7℃/纬度），我们得出纬度温度梯度的值从古新世以来呈不断上升的趋势。这一结果显示65Ma 以来赤道与极地间的温度差异逐渐增大，同时也提示了全球温度可能呈下降趋势。

中国北方花粉--气候走势面研究及内蒙中部全新世环境变迁

本文在对中国北方表土花粉研究的基础上，采用多项式函数回归方法建造了中国北方松属(Pinus)、桦属(Betula)、栎属(Quercus)、蒿属(Artemisia)、藜科(Chenopodiaceae)、菊科(Compositae)、云杉属(Picea)、麻黄属(Ephedra)、禾本科(Gramineae)等的花粉——气候趋势面，从而为利用化石花粉资料直接恢复古气候、古环境提供了一种方便易行的方法;采用多元分析方法对内蒙古中部草原区表土花粉进行了主成分分析，探讨了草原区表土花粉组合的规律及与植被类型的关系;本文还应用孢粉分析方法，结合14C测年技术，通过内蒙古中部察素齐泥炭剖面高分辨率的化石花粉数据，初步恢复了大青山山地南部及土默特平原地区分辨率为70年的全新世以来植被演替和环境变迁的状况，并与邻近地区的全新世古气候、古环境进行了对比研究，研究发现，本区域全新世古环境的变迁序列基本上可以与周围地区及华北地区进行对比，其环境变迁经历了凉干～温湿～暖湿～温干～凉干的变化，且气候最适宜期出现在5000～4100aB.P.期间;最后，对利用花粉——气候趋势面方法恢复古气候进行了尝试和探讨，经与常规方法对比，表明利用趋势面模型重建古气候是一种行之有效的新方法。

中国东北样带孢粉-植被的定量关系及古生物群区的反演

基于中国东北样带（NECT）30个植被样方调查和表土孢粉资料，从个体、群落水平研究了孢粉－植被关系，结果表明，孢粉类型与植被关系密切，在 ＝ 0．05的显著性水平上，相关系数大于0．5;表土孢粉组合与植物群落间有较大的相似性，相似系数大于50％。采用定量描述花粉与植物关系的参数：联合指数（association）A、超代表性指数（over-representation）O、低代表性指数（under-representation）U、相关系数（correlation coefficient）C和代表性系数（representation coefficient）R等值，应用TWINSPAN分类、PCA排序和回归分析，把表土花粉类型划分为4类：具代表性类群组Group1，它们能正确反映植被;超代表性类群组Group2，它们常具有高花粉值与植被不成比例;低代表性类群组Group3，它们的花粉很难分离提取;以及低代表性类群的Group4，其花粉在土壤地层中较常见;指出一些常见花粉类型：松（Pinus）、桦（Betula）、栎（Quercus）、椴（Tilia）、槭（Acer）、榆（Ulmus）、蒿（Artemisia）、藜（Chenopodiaceae）、禾本科（Gramineae）和莎草科（Cyperaceae）的回归参数在东部森林区和西部草原区是有变化的，因此回归参数在应用于古植被恢复中要注意适用范围。 以Biomization模型为基础，根据植物的生理生态特性，定义了NECT孢粉类型的植物功能型（PETs）各种生物群区（Biome）的PFTs组合，构建了经表土孢粉检验的适用于NECT的以孢粉数据为驱动的模型框架，该模型模拟的生物群区与其化指标（气候、植物生理、土壤等）模拟划分的BIOME（Holdrige, BIOME3）是可比的，与植被类型有较好的对应性。 根据29剖面（986个样品）的孢粉数据，重建了NECT 6 kaB.P以来的生物群区。从时空二方面阐述了NECT6kaB.P以来生物群区的分布特点： （1）6ka B. P是一暖湿期，气温比现在高1～4℃，降水比现在多50％。落叶阔叶林分最广，面积最大。森林草原、落叶阔叶林、针阔混交林向西延伸最远。 （2）5ka B. P 是一降温期，气温比现在低2℃，降水多30％。有苔原、寒温带针叶林分布。 （3）4ka B. P是一暖湿期，气温比现在高1～2℃，降水比现在多50％。针阔光林和森林草原有最大分布面积。 （4）3Ka－2kaBP的气温与现代相似，降水比现在多20％左右。与4Ka B. P相比，森林和森林草原过渡带都向东移动。 （5）1Ka B. P的气温与现代相似，降水比现在多10％左右。草原向东大幅度扩张，森林分布面积减小。 （6）东部森林，中部森林草原，西部草原的分布格局的3Ka B. P基本确定，此后随着气候的不断变干冷，草原向东扩张。 （7）森林向扩张最大距离的时期发生在6Ka B. P，此时也是森林草原向西扩张最远时期。落叶阔叶林、针阔混交林、森林草原向西移动最大距离的时间是6Ka B. P，草原向西移动最远距离的时期发生在3Ka B. P。

暖温带地区典型森林群落叶面积指数、生产力和树木年轮特征的分析

以辽东栎(Quercus liaotungensis)为主的落叶阔叶林、华北落叶松林(Larix principisrupprechtii)和油松(Pinus tabulaeformis)林是我国暖温带地区具有代表性的森林群落类型。本研究：1）应用国内外流行的半球图方法，通过对这三种森林群落叶面积指数和林冠开阔度的测定和综合比较，分析了叶面积指数和林冠开阔度的季节动态，揭示了暖温带地区不同类型森林群落叶面积指数和林冠开阔度的特征;2）基于野外调查的样地资料，利用维量分析法估算了中国科学院北京森林生态系统定位研究站三种森林群落乔木层的生物量和生产力，并揭示生产力和叶面积指数之间的相关关系;3）利用油松森林群落和落叶松森林群落采集树芯作为研究对象，用树木年轮学方法，建立相应的年表，联系气候资料进行相关分析，揭示树木生长的限制因子。 研究结果表明：1）落叶阔叶林(优势种为：辽东栎、棘皮桦(Betula dahurica)、五角枫(Acer mono))和华北落叶松林两种落叶森林群落的叶面积指数值均随生长季的到来而呈现增长的趋势，最大值出现在8月;林冠开阔度值随着生长季的到来而下降，最大值出现在11月。落叶阔叶林的叶面积指数和林冠开阔度的季节动态较之华北落叶松林明显。油松是常绿树种，其群落叶面积指数和林冠开阔度的变化程度均不明显，但林冠开阔度的变化趋势也是与叶面积指数的变化趋势相反。通过计算得出叶面积指数和林冠开阔度相关显著，并且呈现指数回归的关系。2） 油松、落叶松、落叶阔叶林三种森林群落乔木层的生物量和生产力分别为93.59 t•hm-2、119.36 t•hm-2 、169.94 t•hm-2和4.02 t•hm-2•a-1、5.58 t•hm-2•a-1、7.04 t•hm-2•a-1;三种森林群落乔木层生产力和叶面积指数回归曲线分析显示，生产力和叶面积指数呈现线性正相关关系。3）油松和落叶松生长与气候因子相关分析结果显示，两种群落树木的生长受当地降水和气温的影响，油松与5月份的温度显著负相关，落叶松与2月份和5月份的降水显著正相关。 以上研究结果为以遥感途径获取暖温带地区叶面积指数提供了地面校正依据，为研究该地区利用LAI估算生产力以及利用遥感途径得到的NDVI测定生产力、研究气候因子对树木年轮宽度形成的影响，以及进一步对该地区林分、景观和区域尺度上碳、水、通量等方面的模拟提供了基础数据。