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1.
 NEWCOP模型是一个新的适于模拟东北森林的种类组成动态的林窗类计算机模拟模型,它通过模拟在每一个林分斑块上的每株树木的更新、生长和死亡的全过程来反映森林群落的中长期生长和演替动态。由于 NEWCOP模型是一个由气候变量驱动的生态系统模型,故可用于评价气候变化对东北森林生长和演替的影响。在东北大兴安岭、小兴安岭和长白山地区对NEWCOP模型进行了验证和校准。沿环境梯度对NEWCOP模型的数字模拟实验表明:它能准确地再现顶极森林中树种组成及其在东北地区的垂直分布规律和水平分布规律;能准确地再现大兴安岭、小兴安岭和长白山的主要类型森林的生长和演替规律;在一定的场合NEWCOP还可反映林分的径级结构;NEWCOP模型还具有对现有森林的跟踪模拟能力。应用NEWCOP模型评估了东北森林生态系统对可能气候变化的敏感性。在GFDL 2×CO2和GISS 2×CO2气候变化情景下,东北森林的种类组成将发生很大变化,落叶阔叶树将取代目前长白山、小兴安岭的红松(Pinus koraiensis)和大兴安岭的兴安落叶松(Larix gmelinii)成为东北森林主要树种,而针叶树将在地带性森林中占很小的比重,阔叶树中蒙古栎(Quercus mongolica)将是最重要的树种,它将成为小兴安岭和大兴安岭最主要树种;东北地区适于森林生长的区域将大幅度减少,这些变化主要发生在气候变化过渡期。东北森林对不同的气候变化情景有不同响应。但是,总的趋势是未来东北森林中落叶阔叶树的比重将大幅度增加。这些结论对在全球气候变化背景下,我国东北合理地选择造林树种和制定现有森林的保护经营策略具有一定参考价值。  相似文献   

2.
Aim Predictions of ecosystem responses to climate warming are often made using gap models, which are among the most effective tools for assessing the effects of climate change on forest composition and structure. Gap models do not generally account for broad‐scale effects such as the spatial configuration of the simulated forest ecosystems, disturbance, and seed dispersal, which extend beyond the simulation plots and are important under changing climates. In this study we incorporate the broad‐scale spatial effects (spatial configurations of the simulated forest ecosystems, seed dispersal and fire disturbance) in simulating forest responses to climate warming. We chose the Changbai Natural Reserve in China as our study area. Our aim is to reveal the spatial effects in simulating forest responses to climate warming and make new predictions by incorporating these effects in the Changbai Natural Reserve. Location Changbai Natural Reserve, north‐eastern China. Method We used a coupled modelling approach that links a gap model with a spatially explicit landscape model. In our approach, the responses (establishment) of individual species to climate warming are simulated using a gap model (linkages ) that has been utilized previously for making predictions in this region; and the spatial effects are simulated using a landscape model (LANDIS) that incorporates spatial configurations of the simulated forest ecosystems, seed dispersal and fire disturbance. We used the recent predictions of the Canadian Global Coupled Model (CGCM2) for the Changbai Mountain area (4.6 °C average annual temperature increase and little precipitation change). For the area encompassed by the simulation, we examined four major ecosystems distributed continuously from low to high elevations along the northern slope: hardwood forest, mixed Korean pine hardwood forest, spruce‐fir forest, and sub‐alpine forest. Results The dominant effects of climate warming were evident on forest ecosystems in the low and high elevation areas, but not in the mid‐elevation areas. This suggests that the forest ecosystems near the southern and northern ranges of their distributions will have the strongest response to climate warming. In the mid‐elevation areas, environmental controls exerted the dominant influence on the dynamics of these forests (e.g. spruce‐fir) and their resilience to climate warming was suggested by the fact that the fluctuations of species trajectories for these forests under the warming scenario paralleled those under the current climate scenario. Main conclusions With the spatial effects incorporated, the disappearance of tree species in this region due to the climate warming would not be expected within the 300‐year period covered by the simulation. Neither Korean pine nor spruce‐fir was completely replaced by broadleaf species during the simulation period. Even for the sub‐alpine forest, mountain birch did not become extinct under the climate warming scenario, although its occurrence was greatly reduced. However, the decreasing trends characterizing Korean pine, spruce, and fir indicate that in simulations beyond 300 years these species could eventually be replaced by broadleaf tree species. A complete forest transition would take much longer than the time periods predicted by the gap models.  相似文献   

3.
以中国东北长白山阔叶红松林为例,应用林窗模型NEWCOP探索了不同模拟样地面积对林窗模型输出结果的影响.结果表明,模拟样地面积大小变化可影响模拟出的森林群落的树种组成和模拟样地的林窗出现周期,通过应用这一特点确定了阔叶红松林的林窗面积为400~800m2.  相似文献   

4.
In the face of climate change and accompanying risks, forest management in Europe is becoming increasingly important. Model simulations can help to understand the reactions and feedbacks of a changing environment on tree growth. In order to simulate forest growth based on future climate change scenarios, we tested the basic processes underlying the growth model BALANCE, simulating stand climate (air temperature, photosynthetically active radiation (PAR) and precipitation), tree phenology, and photosynthesis. A mixed stand of 53- to 60-year-old Norway spruce (Picea abies) and European beech (Fagus sylvatica) in Southern Germany was used as a reference. The results show that BALANCE is able to realistically simulate air temperature gradients in a forest stand using air temperature measurements above the canopy and PAR regimes at different heights for single trees inside the canopy. Interception as a central variable for water balance of a forest stand was also estimated. Tree phenology, i.e. bud burst and leaf coloring, could be reproduced convincingly. Simulated photosynthesis rates were in accordance with measured values for beech both in the sun and the shade crown. For spruce, however, some discrepancies in the rates were obvious, probably due to changed environmental conditions after bud break. Overall, BALANCE has shown to respond to scenario simulations of a changing environment (e.g., climate change, change of forest stand structure).  相似文献   

5.
用森林演替模型BKPF研究黑龙江省伊春地区红松针阔叶混交林采伐迹地上森林演替在未来50年气候变化和CO2浓度增加的反应得出:伊春地区采伐迹地演替50年后红松和硬阔叶树的数量增加,落叶松、山杨与白桦减少;林分密度略有降低;林分生产力增加约7%~28%;林分地上部分总生物量增加15%~24%;叶面积指数增加约5%~8%.气候变化有利于采伐迹地阔叶红松林恢复.  相似文献   

6.
Question: What is the effect of climate change on tree species abundance and distribution in the Italian peninsula? Location: Italian peninsula. Methods: Regression tree analysis, Random Forest, generalized additive model and geostatistical methods were compared to identify the best model for quantifying the effect of climate change on tree species distribution and abundance. Future potential species distribution, richness, local colonization, local extinction and species turnover were modelled according to two scenarios (A2 and B1) for 2050 and 2080. Results: Robust Random Forest proved to be the best statistical model to predict the potential distribution of tree species abundance. Climate change could lead to a shift in tree species distribution towards higher altitudes and a reduction of forest cover. Pinus sylvestris and Tilia cordata may be considered at risk of local extinction, while the other species could find potential suitable areas at the cost of a rearrangement of forest community composition and increasing competition. Conclusions: Geographical and topographical regional characteristics can have a noticeable influence on the impact of predicted climate change on forest ecosystems within the Mediterranean basin. It would be highly beneficial to create a standardized and harmonized European forest inventory in order to evaluate, at high resolution, the effect of climate change on forest ecosystems, identify regional differences and develop specific adaptive management strategies and plans.  相似文献   

7.
用森林动态模型BK荭松针阔叶混交林群落在气候变化和CO2倍增后的反应得出,在气候变化50a后现存的天然红松林林木总株数减少20%以上,地上部分生物量将减少90%以上,蒙古栎的生物量占锯林分的57%以上,林分生产力与现在气候条件下比较接近,略高4%,但主要以蒙古栎、山杨、白桦为主,林分叶面积指数大幅度减少。  相似文献   

8.
气候变化将会对森林树种结构、空间结构以及林龄结构等产生重大影响,准确预测森林景观演替对未来气候变化的响应,不仅能够为科学管理森林生态系统提供理论依据,而且对制定生物多样性保护与珍稀物种保护策略也具有重要意义。本文运用LANDIS Pro 7.0与LINKAGES模型,模拟天宝岩国家级自然保护区8个树种在2种不同气候变化情景(RCP4.5和RCP8.5)下未来300年的森林植被演替动态,分析森林景观格局变化特征及其对气候变化的响应。结果表明:毛竹、马尾松、猴头杜鹃、长苞铁杉以及杉木的潜在面积分布与景观格局指数对气候变化的响应较为显著。在气候变化情景下,各树种的景观分维度均介于1.03—1.08,保护区内各景观斑块相对简单规则。毛竹、猴头杜鹃和杉木聚集度下降趋势明显而斑块密度显著上升,长苞铁杉随演替进行面积逐渐减少而聚集度相对较高且斑块密度剧增,马尾松斑块密度缓慢增加而聚集度先降后升,随气候变化这些树种的景观完整度都遭到了不同程度的破坏,且在RCP8.5气候情景下景观破碎化更严重。而气候变化对阔叶林与柳杉的影响则较小,且阔叶林在演替期间斑块密度下降而聚集度稳中有增,潜在面积分布呈现出良好的...  相似文献   

9.
应用林窗模型LINKAGES对小兴安岭红松针阔混交林在不同季节增温方式下的未来演替过程进行了模拟预测.以温度增加5℃、降水无明显变化作为未来变暖气候的模拟假设,共设计3种气候变暖方式预案,分别为冬季增温幅度大于夏季、冬季与夏季增温幅度相同以及冬季增温幅度小于夏季.模拟结果表明,当冬季增温幅度大于夏季时,小兴安岭现存林分的演替受气候变暖的影响相对最小,树种组成仍然能够保持较为稳定的针阔混交林状态;当冬季增温幅度小于夏季时,现存林分的演替受气候变暖的影响最显著,树种衰退最迅速.可见,小兴安岭针阔混交林的演替与未来的增温方式关系密切,上限温度是现存树种能否继续存活的重要决定因子.  相似文献   

10.
范泽孟  范斌 《生态学报》2019,39(14):5028-5039
欧亚大陆复杂多样的植被生态系统在全球气候变化的驱动下,其时空分布格局将发生系列的偏移变化,进而对欧亚大陆"一带一路"沿线国家和地区的生态环境产生重要影响。如何从全球气候变化驱动的角度来实现欧亚大陆植被生态系统时空偏移趋势的模拟分析,已成为"一带一路"沿线国家和地区生态环境研究的热点科学问题之一。在对HLZ生态系统模型进行改进和构建植被生态系统平均中心时空偏移分析模型的基础上,基于欧亚大陆的气候观测数据(1981—2010年)和CMIP5 RCP2.6、RCP4.5和RCP8.5三种情景数据(2011—2100年),实现欧亚大陆植被生态系统平均中心时空偏移趋势的模拟分析。结果表明:欧亚大陆植被生态系统平均中心主要分布在欧亚大陆的中部和南部地区;3种气候情景下,欧亚大陆的亚热带干旱森林、暖温带湿润森林、亚热带有刺疏林、亚热带潮湿森林、冷温带潮湿森林、寒温带湿润森林、冷温带湿润森林、亚热带湿润森林、暖温带干旱森林、亚极地/高山湿润苔原和极地/冰原等植被生态系统的平均中心偏移幅度大于其他植被生态系统类型;欧亚大陆植被生态系统在RCP8.5情景下的植被生态系统平均中心偏移幅度大于其他两种情景;在2011—2100年期间,3种气候变化情景下,欧亚大陆植被生态系统平均中心整体上将呈向北偏移的变化趋势。  相似文献   

11.
全球气候变暖对陆地生态系统尤其是森林生态系统有着重要的影响,气温升高、辐射强迫的增强将显著改变森林生态系统的结构和功能.南方人工林作为我国森林的重要组成部分,对气候变化的响应日益强烈.为了探究未来气候情景下我国南方人工林对气候变化的响应,降低未来气候变化对人工林可能带来的损失,本研究采用3种最新的气候情景—典型浓度排放路径情景(RCP2.6情景、RCP4.5情景、RCP8.5情景)预估数据,应用生态系统过程模型PnET-Ⅱ和空间直观景观模型LANDIS-Ⅱ模拟2014—2094年间湖南省会同森林生态实验站磨哨实验林场森林的地表净初级生产力(ANPP)、物种建立可能性(SEP)和地上生物量的变化.结果表明: 不同森林类型的SEP和ANPP对气候变化的响应有明显的差异,各森林类型对气候变化的响应程度表现为: 对于SEP,在RCP2.6和RCP4.5情景下,人工针叶林>天然阔叶林>人工阔叶林;在RCP8.5情景下,天然阔叶林>人工阔叶林>人工针叶林.对于ANPP,在RCP2.6情景下,人工阔叶林>天然阔叶林>人工针叶林;在RCP4.5和RCP8.5情景下,天然阔叶林>人工阔叶林>人工针叶林.人工针叶林的地上生物量在2050年左右开始下降,天然阔叶林和人工阔叶林整体呈现上升趋势.2014—2094年,研究区地上总生物量在不同气候情景下增加幅度不同,RCP2.6情景下增加了68.2%,RCP4.5情景下增加了79.3%,RCP8.5情景下增加了72.6%.3种情景下的总地上生物量大小排序为: RCP4.5> RCP8.5> RCP2.6.我们认为,适当的增温将有助于未来研究区森林总地上生物量的积累,但过度的增温也可能会阻碍森林的生产和生态功能的持续发展.  相似文献   

12.
An overview is presented of the phenological models relevant for boreal coniferous, temperate-zone deciduous and Mediterranean coniferous forest ecosystems. The phenology of the boreal forests is mainly driven by temperature, affecting the timing of the start of the growing season and thereby its duration, and the level of frost hardiness and thereby the reduction of foliage area and photosynthetic capacity by severe frost events. The phenology of temperate-zone forests is also mainly driven by temperature. Since temperate-zone forests are mostly mixed-species deciduous forests, differences in phenological response may affect competition between tree species. The phenology of Mediterranean coniferous forests is mainly driven by water availability, affecting the development of leaf area, rather than the timing of phenological events. These phenological models were subsequently coupled to the process-based forest model FORGRO to evaluate the effect of different climate change scenarios on growth. The results indicate that the phenology of each of the forest types significantly affects the growth response to a given climate change scenario. The absolute responses presented in this study should, however, be used with caution as there are still uncertainties in the phenological models, the growth models, the parameter values obtained and the climate change scenarios used. Future research should attempt to reduce these uncertainties. It is recommended that phenological models that describe the mechanisms by which seasonality in climatic drivers affects the phenological aspects of trees should be developed and carefully tested. Only by using such models may we make an assessment of the impact of climate change on the functioning and productivity of different forest ecosystems. Received: 21 October 1999 / Revised: 10 May 2000 / Accepted: 10 May 2000  相似文献   

13.
It has recently been found that the frequency distribution of remotely sensed tree cover in the tropics has three distinct modes, which seem to correspond to forest, savanna, and treeless states. This pattern has been suggested to imply that these states represent alternative attractors, and that the response of these systems to climate change would be characterized by critical transitions and hysteresis. Here, we show how this inference is contingent upon mechanisms at play. We present a simple dynamical model that can generate three alternative tree cover states (forest, savanna, and a treeless state), based on known mechanisms, and use this model to simulate patterns of tree cover under different scenarios. We use these synthetic data to show that the hysteresis inferred from remotely sensed tree cover patterns will be inflated by spatial heterogeneity of environmental conditions. On the other hand, we show that the hysteresis inferred from satellite data may actually underestimate real hysteresis in response to climate change if there exists a positive feedback between regional tree cover and precipitation. Our results also indicate that such positive feedback between vegetation and climate should cause direct shifts between forest and a treeless state (rather than through an intermediate savanna state) to become more likely. Finally, we show how directionality of historical change in conditions may bias the observed relationship between tree cover and environmental conditions.  相似文献   

14.
森林动态模型概论   总被引:18,自引:0,他引:18  
讨论了模拟森林林分动态变化的模型,并把模型分为森林生长模型和演替模型。森林生长模型包括:全林分模型、林分级模型和单木模型;演替模型包括马尔可夫类模型和林窗模型。文中给出了演替模型的基本原理和适用性,在比较早期和最新发展的林窗模型后,叙述了林窗模型的新进展。生长和演替模型的结构和数据要求不同决定了它们的在时间和空间上的适应性,最后指出模型将向综合总体方向发展  相似文献   

15.
Norway spruce is one of the economically most important tree species in Central European forestry. However, its high susceptibility to droughts poses a strong challenge to its cultivation under future conditions with likely more frequent and prolonged droughts and shifts in the seasonal climate. To compensate for expected losses of forest areas suitable for the cultivation of spruce, more drought-tolerant species are required. Silver fir and Douglas fir are two potential candidates, which promise lower drought susceptibility and equal or even higher yield when compared to Norway spruce.Using the Black Forest as a regional case study, we assessed the effects of seasonal climate change, including drought stress, on tree-ring width formation of these three economically relevant conifer species over the last 60 years. In addition, we projected potential species-specific growth changes under different climate change scenarios until 2100.Our results suggest that both silver fir and Douglas fir will possibly experience growth increases in a warmer future climate, as predicted under the 4.5 and 8.5 Representative Concentration Pathway (RCP) climate change scenarios, whereas growth of spruce is expected to decline. Moreover, drought susceptibility in silver fir and Douglas fir is lower than in spruce, as shown for past drought events, and their ability to benefit from milder winters and springs could play a major role in their capacity to compensate for drier summers in the near to mid-term future. This study highlights the need to advance our understanding of the processes that drive drought resistance and resilience in tree species to guide management strategies in the face of climate change.  相似文献   

16.
季节性雪被变化对森林凋落物分解及土壤氮动态的影响   总被引:2,自引:0,他引:2  
全球气候变化引发的雪被格局变化将深刻影响植被的凋落物分解、陆地生态系统的土壤养分循环等过程.森林是陆地生态系统的主体,在全球生物地球化学循环中起着不可替代的作用.本研究综述了季节性雪被变化对森林凋落物分解及土壤氮动态的影响.全球气候变化情景下季节性雪被表现出因地域而异的增加或减少的变化格局,一方面通过改变环境温湿度、凋落物质量、分解者动态等直接影响分解过程,另一方面通过改变森林群落结构、植被物候、土壤养分等间接地作用于凋落物分解.同时,季节性雪被通过影响氮富集作用、雪被下土壤温湿度、冻融循环、森林群落、雪下动物和微生物等相关因子而改变森林土壤氮循环.本领域未来应开展的研究是: 1) 全面考虑全球气候变化情景下季节性雪被格局的变异性,开展不同季节性雪被格局变化的模拟研究;2) 开展季节性雪被融雪水淋溶作用对森林凋落物分解和土壤氮动态的影响研究;3) 阐明不同生态系统和气候带中季节性雪被格局变化对森林凋落物分解过程和土壤氮动态的驱动机制研究;4) 量化季节性雪被变化对森林凋落物分解和土壤氮动态在雪被覆盖期的瞬时影响和无雪期的延续影响,为阐明和模型预测陆地生态系统生物地球化学循环对全球气候变化的响应提供理论基础和数据支持.  相似文献   

17.
The Forest Health Monitoring (FHM) and Forest Inventory and Analyses (FIA) programs are integrated biological monitoring systems that use nationally standardized methods to evaluate and report on the health and sustainability of forest ecosystems in the United States. Many of the anticipated changes in forest ecosystems from climate change were also issues addressed in sections of FHM's National Technical Report 1991 to 1998. The integrated FHM and FIA monitoring systems are currently establishing baseline conditions (status and change) in most States for many of the expected effects, and are projected to have full implementation for all States and Territories in 2003. These monitoring systems utilize a broad suite of indicators of key ecosystem components and processes that are responsive to many biotic and abiotic stressors, including those anticipated from climate change. These programs will contribute essential information for many decades for many of the anticipated changes in forest ecosystem from increasing carbon dioxide concentrations, changing climatic scenarios, and extreme weather events that are probable in the next 30 to 100 years.  相似文献   

18.
Climate change is an important factor affecting forest growth. Therefore, approaching the impacts of climate change on forest growth is of great significance to ameliorate this degraded land and push up forestry development. This paper initially probes the impacts of climate change on tree growth in Yellow River Delta region and responds of different tree species on the change. In this study, five species of 22-year-old trees were selected, and the tree biomass was measured by standard site methods and tree ring sampling to pursue the impacts of climate change on forest growth. Besides, growth models of the different tree species were established and verified using Robinia pseudoacacia as an example. The results showed: (1) In the Yellow River Delta, the most adapted tree species are Fraxinus chinensis and R. pseudoacacia. (2) Precipitation is the main meteorological factor affecting tree growth, while temperature and air pressure are also significantly correlated with tree growth. (3) Linear and power function models can simulate tree growth well. From the verification results, the modified R. pseudoacacia biomass is 294.54 t/ha, and the simulated biomass of the linear function model is close to the value. It is expected that the research not only provides a theoretical basis for forestry development in saline lands, but also helps to rehabilitate saline-alkali lands and cope with climate change.  相似文献   

19.
使用LPJ-GUESS植被动态模型, 在北京山区研究了未来100a以辽东栎 (Quercus liaotungensis) 为优势种的落叶阔叶林、以白桦 (Betula platyphylla) 为主的阔叶林和油松 (Pinus tabulaeformis) 为优势种的针阔混交林的碳变化, 定量分析了生态系统净初级生产力 (NPP) 、土壤异养呼吸 (Rh) 、净生态系统碳交换 (NEE) 和碳生物量 (Carbon bio-mass) 对两种未来气候情景 (SRES A2和B2) 以及相应大气CO2浓度变化情景的响应特征。结果表明:1) 未来100a两种气候情景下3种森林生态系统的NPP和Rh均增加, 并且A2情景下增加的程度更大;2) 由于3种生态系统树种组成的不同, 未来气候情景下各自NPP和Rh增加的比例不同, 导致三者NEE的变化也相异:100a后辽东栎林由碳汇转变为弱碳源, 白桦林仍保持为碳汇但功能减弱, 油松林成为一个更大的碳汇;3) 3种森林生态系统的碳生物量在未来气候情景下均增大, 21世纪末与20世纪末相比:辽东栎林在A2情景下碳生物量增加的比例为27.6%, 大于B2情景下的19.3%;白桦林和油松林在B2情景下碳生物量增加的比例分别为34.2%和52.2%, 大于A2情景下的30.8%和28.4%。  相似文献   

20.
Precise knowledge how tree growth will respond to future climate change is essential for the adapted management of forest ecosystems. By conducting sensitivity tests, tree-ring process-based cambial growth models can provide an innovative way to better understand wood formation under different climate change scenarios. As a case study in semi-arid north central China, we used artificially increased or decreased daily climatic data as input to the Vaganov-Shashkin dynamic growth model to investigate the response of wood formation to climatic change. By calibrating the tree-ring model using daily climate data over the period 1951–2010, we found that 81% of radial growth was driven by soil moisture, while 13% of growth was controlled by temperature. During the main growing season June–August, significant differences in the integral growth rate occurred after changing precipitation by ± 30% or by decreasing temperature by 3.0 °C (p < 0.05). However, increasing temperature showed only modest effects on tree radial growth rate. During the past 60 years, a significant advancement of the starting dates of growth was detected, whereby non-significant variability was found for the ending dates of growth. Contemporaneously, the effect of previous winter temperature (previous December to current January) on cambial growth initiation declined after 1980. Significant differences in the growth onset dates only occurred when temperature was reduced by 4.5 °C or increased by 5.5 °C. Moreover, both the onset and ending dates of growth in the study region were more sensitive to cooling rather than to warming. If temperature will increase by 2°C and precipitation will increase by 30% at the end of this century as predicted by some Earth system models, tree radial growth might increase by 19% in the study region, compared to the average during the period 1952–2010. Consequently, tree stem radial growth is expected to increase under a warming and wetting climatic scenario, but will decrease under drying conditions.  相似文献   

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