Cold Temperate Coniferous Forest Research Articles

MODIS-Derived Estimation of Soil Respiration within Five Cold Temperate Coniferous Forest Sites in the Eastern Loess Plateau, China

Soil respiration (Rs) is seldom analyzed using remotely sensed data because satellite technology has difficulty monitoring various respiratory processes in the soil. We investigated the potential of remote sensing data products to estimate Rs, including land surface temperature (LST) and spectral vegetation indices from the Moderate Resolution Imaging Spectroradiometer (MODIS), using a nine-year (2007–2015) field measurement dataset of Rs and soil temperature (Ts) at five forest sites at the eastern Loess Plateau, China. The results indicate that soil temperature is the primary factor influencing the seasonal variation of Rs at the five sites. The accuracy of the model based on the observed data is not significantly different from the model based on MODIS-derived nighttime LST values. There was a significant difference with the model based on MODIS-derived daytime LST values. Therefore, nighttime LST was the optimum LST for estimation of Rs. The normalized difference vegetation index (NDVI) consistently exhibited a stronger correlation with Rs when compared to the green edge chlorophyll index and enhanced vegetation index. Further analysis showed that adding the NDVI into the model considering only Ts or nighttime LST could significantly improve the simulation accuracy of Rs. The models depending on nighttime LST and NDVI showed comparable accuracy with the models based on the in situ Ts and NDVI. These results suggest that models based entirely on remote sensing data from MODIS have the potential to estimate Rs at the cold temperate coniferous forest sites. The performance of the model in other vegetation types or regions has also been proved. Our conclusions further confirmed that it is feasible for large-scale estimates of Rs by means of MODIS data in temperate coniferous forest ecosystems.

Spatiotemporal changes in forest loss and its linkage to burned areas in China

Fire-induced forest loss has substantially increased worldwide over the last decade. In China, the connection between forest loss and frequent fires on a national scale remains largely unexplored. In this study, we used a data set for a time-series of forest loss from the Global Forest Watch and for a MODIS-derived burned area for 2003–2015 to ascertain variations in forest loss and to explore its relationship with forest fires (represented by burned areas) at the country- and forest-zone levels. We quantified trends in forest loss during 2003–2015 using linear regression analysis and assessed the relation between forest loss and burned areas using Spearman’s correlation. Forest loss increased significantly (264.8 km2 a−1; R2 = 0.54, p < 0.01) throughout China, with an average annual increase of 11.4% during 2003–2015. However, the forest loss trend had extensive spatial heterogeneity. Forest loss increased mainly in the subtropical evergreen broadleaf forest zone (315.0 km2 a−1; R2 = 0.69, p < 0.01) and tropical rainforest zone (38.8 km2 a−1; R2 = 0.66, p < 0.01), but the loss of forest decreased in the cold temperate deciduous coniferous forest zone (− 70.8 km2 year−1; R2 = 0.75, p < 0.01) and the temperate deciduous mixed broadleaf and coniferous forest zone (− 14.4 km2 a−1; R2 = 0.45, p < 0.05). We found that 1.0% of China’s area had a significant positive correlation (r ≥ 0.55, p < 0.05) with burned areas and 0.3% had a significant negative correlation (r ≤ − 0.55, p < 0.05). In particular, forest loss had a significant positive relationship with the burned area in the cold temperate deciduous coniferous forest zone (16.9% of the lands) and the subtropical evergreen broadleaf forest zone (7.8%). These results provide a basis for future predictions of fire-induced forest loss in China.

The effects of nitrogen addition on dissolved carbon in boreal forest soils of northeastern China

Understanding the effects of nitrogen (N) addition on dissolved carbon in boreal forest soils is essential for accurate evaluation of regional carbon balances. The objective of this study was to determine the effects of different levels and types of N addition on soil dissolved carbon concentration in a cold-temperate coniferous forest through an in-situ fertilization experiment. Simulated atmospheric N addition was applied in a factorial experiment with N addition level (control, 10, 20 and 40 kg of N ha−1yr−1) and N type (NH4Cl, KNO3 and NH4NO3) treatments. The experiment was conducted over the 2010 growing season (May-September) at the Kailaqi farm of Genhe Forestry Bureau, located in the northern Great Xin’an mountain range, northern China. Monthly N addition treatments were applied in three replicate plots per treatment (n = 36), and measurements of dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) were derived from monthly sampling of the organic and mineral soil horizons. There was a significant effect of N type, with the combined N source (NH4NO3) producing significantly higher DOC than the control (ambient addition) or the NH4Cl treatment in both the organic and mineral layers. The N addition treatment increased DIC in the organic layer at the low levels only, while N type did not have a significant effect. There was a significant interaction of the month and the N level treatment, as low level N addition tended to increase the content of soil DOC while high level N tended to inhibit soil DOC content, with these trends being most pronounced in the middle of the growing season. These results elucidate the importance of the type and timing of N additions to the dynamics of soil carbon pools.

Changes of vegetation in southern China

In order to reveal the changes of vegetation in southern China since the Last Glacial Maximum, we have established high-resolution time scales and palynological sequences of borehole profiles by drilling cores in some weak areas of the research to restore vegetation changes over the past 20,000 years on the basis of previous work. This paper gives the vegetation zoning maps of 18, 9 and 6 ka BP respectively in southern China, and describes the distribution characteristics of plants in different zones/subzones. The results show that the vegetation zonations around 18 ka BP were significantly different from that at present. It appeared in turn with Cold-temperate coniferous forest and alpine meadow steppe zone, and Temperate mixed coniferous and broad-leaved forest zone/warm temperate deciduous broad-leaved forest zone from northwest to southeast in the west, and Temperate mixed coniferous and broad-leaved forest zone, Warm temperate deciduous broad-leaved forest zone, and Northern subtropical mixed evergreen and deciduous broad-leaved forest zone from north to south in the central and east. The vegetation distribution around 9 ka BP changed distinctively. Except that the northwest part was located in Mountain temperate mixed coniferous and broad-leaved forest zone, the vegetation in other areas occurred in turn with North subtropical mixed evergreen and deciduous broad-leaved forest subzone, Mid-subtropical typical evergreen broad-leaved forest subzone, and South subtropical monsoon evergreen broad-leaved forest subzone/Tropical seasonal rainforest and rainforest zone from north to south. There was little change in the appearance of vegetation zonations between 6 and 9 ka BP, but the northern edge of each vegetation belt moved a little northward, reflecting that the overall climate became warmer around 6 ka BP. The vegetation changes in southern China over the past 20,000 years were largely driven by environmental changes. Climate change was the main factor affecting the vegetation distribution. The impact of human activities became more and more remarkable in the later period. In the lower reaches of the Yangtze River and the delta region, sea level changes also influenced the vegetation distribution.

A late Miocene-early Pleistocene palynological record and its climatic and tectonic implications for the Yunnan Plateau, China

In this paper, we provide a late Miocene (Tortonian) to early Pleistocene (Gelasian) palynological record from the Eryuan Basin, Yunnan Plateau, China, to investigate plant diversity over this time. Between 7.6 and 4.3 Ma, the palynological assemblage was dominated by coniferous trees (70.2% on average), with subordinate amounts of broadleaved trees (8.8% on average). This suggests that the vegetation mainly comprised mixed forests, and that the climate was relatively warm and humid. After 4.3 Ma, the proportion of conifer pollen increased overall, and amount of cold-temperate coniferous forest Picea and Abies pollen, in particular, increased significantly (from 19.1% to 41.9%), concurrent with decreases in the pollen of broadleaved trees, shrubs, herbs, and other plant taxa. We suggest that these plant variations and overall reduced diversity may be responses to the tectonic uplift of the Yunnan Plateau and global cooling.

Vegetation damage, post-disaster change degree and driving factors in the cold temperate wind disaster area of Changbai Mountain, China.

The typhoon outbreaks of 1986 caused many gaps in the cold temperate coniferous forest and Betula errmanii forest on the western and southern slopes in the Changbai Mountain. In 2017, a research area at the 1600-1800 m altitude in Changbai Mountain was established to explore the damage and changes of forest vegetation disturbed by the typhoon in cold temperate zone and to reveal the regulation of damage on vegetation and post-disaster change as well as the driving factors. The remote sensing data were used to classify research area based on the degree of vegetation damage and post-disaster change. A total of 40 plots were set up for vegetation survey. According to the damage degree of forest structure, three levels of severity of damage to vegetation in the cold temperate zone of Changbai Mountain were classified including gently, moderately, and severely damaged, in which moderately damaged area was largest, followed by gently damaged area and severely damaged area. Tree damage significantly differed among three level areas, with 20%, 50% and 85% reduction of the abundance of dominant trees in gently, moderately and severely damaged areas, respectively. The wind resistance ability of B. errmanii was higher than that of Picea jezoensis. The wind resistance ability of B. errmanii with larger diameter grade was higher than that of those with smaller diameter grade. The severity of damage to vegetation was strongly correlated with slope, with lower severity on the steeper slop area. From 1987 to 2017, the vegetation of wind disaster area significantly changed. The study area could be classified into three levels based on the degree of changing: fast, medium, and slow, with largest area in medium changed, followed by slowly and fast changed. The degree of vegetation changes was strongly correlated with altitude, with slower change at higher altitude area. The recovery rate of trees was slow, with P. jezoensis recovering slightly quicker than B. errmanii. The vegetation change mainly occurred in shrub and herb layers. Shrub layer recovered better than the herb layer in the fast changed area, while herb layer recovered better than the shrub layer in the medium changed area. In the slowly changed area, herb layer was generally low and dense with varying shrub layer.

Vegetation pattern of Northeast China during the special periods since the Last Glacial Maximum

Since the Last Glacial Maximum (LGM), the global climate has experienced several stages, such as cold and warming events, which provide an ideal model for evaluating climate change in the future. Based on the pollen records in Northeast (NE) China, the vegetation pattern during special periods since the LGM was reconstructed in this work. During the LGM (approximately 18,000 cal yr BP), the steppes expanded rapidly in NE China, and a cold-dry meadow-steppe developed on the Songnen Plain. The Liaohe Plain and the Hulun Buir Plateau were occupied by a steppe-desert, with forest-steppe vegetation grown in the central and southern plains; there were cold-dry coniferous forests and mixed conifer-broadleaf forests in mountainous areas. In the early Holocene (10,000–9,000 cal yr BP), Changbai mountain (CBM) forests thrived in the eastern hilly area and the Sanjiang Plain, while the central region was dominated by steppes, and warm-temperate broadleaf forests developed northward. During the Holocene warm period (approximately 6,000 cal yr BP), CBM forests and cold-temperate coniferous forests developed in the north, while spruce-fir forests developed in the eastern Xiao Hinggan Mountains and the Sanjiang Plain. The distribution centre of deciduous broadleaf forests migrated to the south of the Changbai Mountains and the Liaodong Peninsula. The isolated woodlands increased on the Songnen Plain and the meadow-steppes expanded to the Liaohe Plain. Therefore, the increase in temperature leads to the increase of monsoon precipitation in NE China, which is beneficial to the development of warm-temperate forest vegetation. The increase of summer monsoons and precipitation caused by climate warming may be the main reason for the improved plant load.

Late Cenozoic palynofloras revealing significant environment and climate changes in Changbai Mountain area, NE China

The present climate in the Changbai Mountain area, NE China is warm with abundant rainfall. It is mainly affected by the wet air mass from the Sea of Japan. Local vegetation belongs to the warm temperate mixed conifer and broad-leaved forest, with a mountain cold temperate coniferous forest belt occurring at an altitude of over 1100 m. The Neogene vegetation history of this region is not yet well understood because of the lack of palaeobotanical data. Here we report a systematic palynological result of a plant-bearing diatomite sequence at Badaogou of Changbai Mountains in Jilin Province, which shows distinct vegetation and environment changes during the late Neogene. Seven palynological assemblages are recognized in the diatomite deposits from a freshly closed mine (Zones M-I and M-II), and an outcrop (Zones I–V) respectively in ascending order. Pollen data indicate a dominant woody angiosperm plants such as Ulmus, Quercus, Pterocarya and Fagus etc. at first (Zone M-I). Subsequently, gymnosperm plants mainly represented by Pinus, Tsuga, Picea and Abies show an increase (Zone M-II), and become predominant at a lowest sample in the outcrop (Zone I), distinguished by rich Picea, along with large amount of Tsuga, Pinus and Abies. Pinus increases significantly, while Picea remains higher value, and Abies and Tsuga become limited in the following assemblage (Zone II). Woody angiosperm pollen Tilia, and terrestrial herbs and shrubs including Asteraceae and Chenopodiaceae show their first sign of increase in Zone III, and become more distinguishable in Zone IV. Picea rises again in Zone V. Pollen assemblages display a successive change of vegetation between the mine (Zones M-I and M-II) and the outcrop (Zones I–V), reflecting their continuity in time. Based on the Ar–Ar dating, the outcropping deposits (Zones I–V) are the Latest Pliocene in age, approaching to the Plio-Pleistocene boundary. Consequently, pollen data in this study indicate a major turnover from the warm temperate mixed conifer and broad-leaved forest (Zones M-I and M-II) to the cold temperate coniferous forest (Zone I) during the Late Pliocene in the Changbai Mountain area. It also displays some subsequent fluctuations including the warm temperate mixed conifer and broad-leaved forest partly recovered in Zones III and IV, and decreased again in Zone V. It shows for the first time how local vegetation responses to the global climate deterioration in the Late Pliocene of NE China. The overall changing process is more or less comparable with some simultaneous vegetation changes in North China and Central Japan. The terrestrial herbs and shrubs in the assemblages are not significant comparing with other areas in North China, reflecting the influence of wet air mass from the Sea of Japan. Meanwhile, Tsuga is gradually disappearing in the upper assemblages as a result of continuous lower temperature.

Abiotic and biotic drivers of species diversity in understory layers of cold temperate coniferous forests in North China

Understory plants are important components of forest ecosystems and play a crucial role in regulating community structures, function realization, and community succession. However, little is known about how abiotic and biotic drivers affect the diversity of understory species in cold temperate coniferous forests in the semiarid climate region of North China. We hypothesized that (1) topographic factors are important environmental factors affecting the distribution and variation of understory strata, and (2) different understory strata respond differently to environmental factors; shrubs may be significantly affected by the overstory stratum, and herbs may be more affected by surface soil conditions. To test these hypotheses, we used the boosted regression tree method to analyze abiotic and biotic environmental factors that influence understory species diversity, using data from 280 subplots across 56 sites in cold temperate coniferous forests of North China. Elevation and slope aspect were the dominant and indirect abiotic drivers affecting understory species diversity, and individual tree size inequality (DBH variation) was the dominant biotic driver of understory species diversity; soil water content was the main edaphic factors affecting herb layers. Elevation, slope aspect, and DBH variation accounted for 36.4, 14.5, and 12.1%, respectively, of shrub stratum diversity. Shrub diversity decreased with elevation within the range of altitude of this study, but increased with DBH variation; shrub diversity was highest on north-oriented slopes. The strongest factor affecting herb stratum species diversity was slope aspect, accounting for 25.9% of the diversity, followed by elevation (15.7%), slope (12.2%), and soil water content (10.3%). The highest herb diversity was found on southeast-oriented slopes and the lowest on northeast-oriented slopes; herb diversity decreased with elevation and soil water content, but increased with slope. The results of the study provide a reference for scientific management and biodiversity protection in cold temperate coniferous forests of North China.

Response of the water use efficiency of natural vegetation to drought in Northeast China

Drought has become a problem that is universally faced by global terrestrial ecosystems. Northeast China is located in a region sensitive to global climate changes, and one of the main impacts of climate changes in Northeast China is manifested as drought in growing seasons. This study analyzes the spatio-temporal evolution law of the water use efficiency (WUE) of the main natural vegetation (i.e., cold-temperate coniferous forests, temperate pine-broad-leaved mixed forests, warm-temperate deciduous broad-leaved forests, and grasslands) in Northeast China based on public MODIS data products, including MCD12Q1, MOD15A2H, MOD16A2, and MOD17A3H, and meteorological data from 2002 to 2013. The influence of drought events on the WUE of different vegetation types and their response to drought events are also investigated. The study findings are as follows: (1) drought in Northeast China frequently occurs in the regions stretching from 114.55°E to 120.90°E, and the percentage of drought area among the forests is lower than that among the grasslands during these years; (2) the annual average WUE of the natural vegetation ranges from 0.82 to 1.08 C/kg−1H2O, and the WUE of forests (0.82 to 1.08 C/kg−1H2O) is universally higher than that of grasslands (0.84 to 0.99 C/kg−1H2O; (3) in 2008, the regions where the WUE in drought conditions is higher than that in normal water conditions account for 86.11% of the study area, and a significant linear positive correlation is found between the WUE in drought conditions and the WUE in normal water conditions, whereas the degree of drought does not influence the WUE of the natural vegetation in an obviously linear manner; and (4) the WUE for the cold-temperate coniferous forests and temperate pine-broad-leaved mixed forests with a high ET or low NPP is more likely to rise in drought conditions; the WUE for the grasslands with a low Evapotranspiration (ET), Net Primary Production (NPP), and Leaf Area Index (LAI) is more likely to rise in drought conditions; and the ET, NPP, and LAI have no significant influence on the WUE for the warm-temperate deciduous broad-leaved forests in drought conditions. This study contributes to improving the evaluation of the influence of drought on natural ecosystems.

Species composition, structure and spatial distribution of secondary cold-temperate Picea forest in Guandi Mountain, China

The secondary Picea forest is one of the dominant vegetation types in Guandi Mountain. It's also the representative type of evergreen cold-temperate coniferous forests in subalpine region of north China. A 4 hm2 fixed monitoring Picea forest plot was established in Pangquangou Nature Reserve, Guandi Mountain (GDS plot) to better understand the basic characteristics such as species composition, community structure and its potential ecological process and mechanisms. We analyzed species composition, structure and spatial distribution of sample forest based on the first background survey data in this paper. The results showed that a total of 30 woody plant species existed in the sample area, which belonged to 11 families, 22 genera. The total individual number (including branches) was 26218 (independent individual number was 10266). Floristic composition in the region was defined as north temperate elements. Big differences of individual number, average diameter at breast height (DBH) and basal area among different species caused significant community layering effect, and the dominant species in each layer was obvious. Size-class structure of species showed bimodal skewed normal distribution at the canopy layer, approximate normal distribution at the subtree layer, and 'L' type distribution at the shrub layer. Spatial distribution of the dominant tree species such as Picea wilsonii and Larix principis-rupprechtii showed different pattern features with the changing size class, whether in individual number or in aggregation degree. Compared with the above two species with the same size class, a large number of L. principis-rupprechtii with DBH≥30 cm aggregated in the center of sample plot, but few P. wilsonii individuals with DBH≥30 cm occurred in the plot and had no clustering distribution. Only a few L. principis-rupprechtii with DBH≤10 cm occurred in the plot with a scattering distribution, and a large number of P. wilsonii with DBH≤10 cm aggregated in the center of the plot. There were also many P. wilsonii individuals with DBH≤10 cm distributed in the northwest area of the plot, but Betula albo-sinensis individuals with DBH≤10 cm mostly distributed in the southeast area of the plot. Shrub species such as Cotoneaster acutifolius, Spiraea pubescens and Lonicera szechuanica also showed heterogeneous spatial distribution. Species distribution pattern was affected by habitat conditions, and related to its own development, regeneration traits and ecological habits.

氮素类型和剂量对寒温带针叶林土壤N2O排放的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 氮素类型和剂量对寒温带针叶林土壤N2O排放的影响 DOI: 10.5846/stxb201508041639 作者: 作者单位: 中国科学院地理科学与资源研究所,中国科学院大学资源与环境学院,中国科学院地理科学与资源研究所,中国科学院地理科学与资源研究所,中国科学院大学资源与环境学院,中国科学院地理科学与资源研究所,中国科学院地理科学与资源研究所,中国科学院大学资源与环境学院,中国科学院大学资源与环境学院 作者简介: 通讯作者: 中图分类号: Q142 基金项目: 国家自然科学基金项目（41471212，31470558，31290221，31130009，31290222）；国家重点基础研究发展计划项目（2012CB417103）；中国科学院地理科学与资源研究所“秉维”优秀青年人才基金项目（2011RC202）；中国科学院战略性先导科技专项（XDA05050600） The effects of types and doses of nitrogen addition on soil N2O flux in a cold-temperate coniferous forest, northern China Author: Affiliation: Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences,College of Resources and Environment,University of Chinese Academy of Sciences,Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences,Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences,College of Resources and Environment,University of Chinese Academy of Sciences,Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences,Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences,College of Resources and Environment,University of Chinese Academy of Sciences,College of Resources and Environment,University of Chinese Academy of Sciences Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:大气氮沉降输入会增加森林生态系统氮素有效性，进而改变土壤N2O产生与排放，然而有关不同氮素离子（氧化态NO3--N与还原态NH4+-N）沉降对土壤N2O排放的影响知之甚少。以大兴安岭寒温带针叶林为研究对象，构建了3种类型（NH4Cl、KNO3、NH4NO3）和4个施氮水平（0、10、20、40 kg N hm-2 a-1）的增氮控制试验，利用流动化学分析仪和静态箱-气相色谱法4次/月测定凋落物层和矿质层土壤无机氮含量、土壤-大气界面N2O净交换通量以及相关环境因子，分析施氮类型和剂量对土壤氮素有效性、土壤N2O通量的影响，探讨氮素富集条件下土壤N2O通量的环境驱动机制。结果表明：施氮类型和剂量均显著影响土壤无机氮含量，土壤NH4+-N的积累效应显著高于NO3--N。施氮一致增加寒温带针叶林土壤N2O排放，NH4NO3促进效应最为明显，增幅为442%-677%，高于全球平均水平（134%）。土壤N2O通量与土壤温度、凋落物层NH4+-N含量正相关，且随着施氮水平增加而增加。结果表明大气氮沉降短期内不会导致寒温带针叶林土壤NO3--N大量流失，但会显著促进土壤N2O的排放。此外，外源性NH4+和NO3-输入对土壤N2O排放的促进作用具有协同效应，在未来森林生态系统氮循环和氮平衡研究中应该区分对待。 Abstract:Increasing atmospheric nitrogen (N) deposition would change soil N availability, and thereby changes N2O production and emission from N-limiting forest soils. However, it is still unclear about the contrasting effects of different N ion (i.e., oxidized NO3--N and reduced NH4+-N) deposition on soil N2O emission in boreal forests. In the present study, a cold-temperate coniferous forest in the Great Khingan region was selected for conducting the manipulative N addition experiment, including three forms of N fertilizers (NH4Cl, KNO3, and NH4NO3) and four rates of N addition (0, 10, 20, and 40 kg N hm-2 a-1). Soil-atmospheric N2O exchanging fluxes were measured four times per month using static chamber-gas chromatography. Simultaneously, soil temperature, moisture, and inorganic N contents were measured to explore how the main factors affect soil N2O emission. The results showed that the types and doses of N addition significantly changed soil inorganic N contents, and the accumulation of soil NH4+-N was significantly higher than that of soil NO3--N due to N addition. N addition increased N2O emission from the boreal forest soil, and the NH4NO3 addition treatments promoted high soil N2O fluxes, with an increase of 442% to 667%, which was higher than the global average (134%). There were positive correlations between soil N2O fluxes and soil temperature, and between soil N2O fluxes and soil NH4+-N contents in the litter layer. Soil N2O fluxes were driven by soil temperature, followed by soil NH4+-N contents in the litter layer. These findings suggest that atmospheric N deposition cannot lead to a significant soil NO3--N leaching and loss in boreal forests over the short term, but it can significantly promote soil N2O emission. Furthermore, exogenous NH4+ and NO3- inputs into boreal forests have synergic effects on soil N2O emission, which should be distinguished in N cycle and balance in terrestrial ecosystems using 15N tracer methods in the future. 参考文献 相似文献 引证文献

气候变化对东北主要地带性植被类型分布的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 气候变化对东北主要地带性植被类型分布的影响 DOI: 10.5846/stxb201607071393 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 2015年中国气象局气候变化专项（CCSF201512）；中国气象局沈阳大气环境研究所2016年开放基金课题（2016SYIAE11）；2013年公益性行业（气象）科研专项经费项目（GYHY201306036）。 Effects of climate change on the distribution of main vegetation types in Northeast China Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:准确地划分地带性主要植被类型分布的适宜区域，可为区域植被恢复与重建、生物多样性保护等工作提供有益的理论参考。在检验1961-2013年东北地区气候变化突变点的基础上，基于东北地区主要植被类型热量指标，研究气候变化对该区域主要植被类型适宜分布区域的影响，并利用2000年和2013年土地类型覆盖数据（MCD12Q1），对推算的适宜分布区域进行验证，结果表明：大兴安岭气温突变点为1982年，其它地区为1988年，东北地区各生态地理区年降水量没有明显的突变点。气温突变点后适宜在东北地区生长的主要植被种类没有变化，但各植被类型的分布区域均有所改变，其中高山冻原、亚高山矮曲林、寒温带针叶林和温带针阔叶混交林适宜分布区域面积减小，暖温带落叶阔叶林和温带草原面积增大。气温突变点前后各植被类型适宜分布区的地理中心均发生了不同程度的移动，其中移动距离最大的是南部地区的亚高山矮曲林，向东北方向移动了135.44km。与主要植被类型实际分布相对比，证明气候变化对研究区植被类型分布可能已经产生了影响。 Abstract:A suitable distribution of zonal vegetation types could provide a reference for the restoration and reconstruction of regional vegetation and protection of biodiversity. Between 1961 and 2013, we used mutation point detection and the thermal index to study the impacts of climate change on the distribution of the main vegetation types in Northeast China. The land cover data for 2000 and 2013 from NASA LPDAAC (The Land Processes Distributed Active Archive Center) EOS were used to verify the simulated distribution regions. The results showed that the temperature mutation point for Daxing'an Mountains was in 1982, and the mutation points for the other regions were in 1988. The annual precipitation at each eco-geographical region showed no obvious mutation. After 1982, the main vegetation types, which were suitable for growth,showed no obvious changes;however, their distribution regions had been changed. The areas of suitable distribution regions for alpine tundra, subalpine forest, cold-temperate coniferous forest, and temperate mixed forest decreased continuously;however, the areas for warm-temperate deciduous broad-leaved forest and temperate grassland increased. The geographic centers for the suitable distribution of each vegetation type had moved to different degrees before and after the temperature mutation points. Among them, the center of the subalpine forest had moved towards the northeast, and the distance was the longest (135.44km). On the basis of the comparative analysis,we concluded that climate change possibly had an impact on the distribution of vegetation types in Northeast China. 参考文献 相似文献 引证文献

庞泉沟自然保护区常见禾本科植物内生真菌分布及其影响因素

PDF HTML阅读 XML下载 导出引用 引用提醒 庞泉沟自然保护区常见禾本科植物内生真菌分布及其影响因素 DOI: 10.5846/stxb201605311040 作者: 作者单位: 山西大学黄土高原研究所,山西大学黄土高原研究所,山西大学黄土高原研究所,山西大学黄土高原研究所,山西大学黄土高原研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 山西省应用基础研究面上青年基金项目（201601D021101）；山西省回国留学人员科研资助项目（2016-006）；山西省科技攻关项目（20150313001-3）；国家自然科学基金资助项目（31600308） Distribution of endophyte fungi associated with common plants and preliminary assessment of impact factors in Pangquangou Nature Reserve Author: Affiliation: Institute of Loess Plateau,Shanxi University,Institute of Loess Plateau,Shanxi University,Institute of Loess Plateau,Shanxi University,Institute of Loess Plateau,Shanxi University,Institute of Loess Plateau,Shanxi University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以庞泉沟自然保护区4种不同群落类型林地和灌丛下的优势禾草为研究对象，调查不同禾草内生真菌感染率，研究内生真菌感染的禾草种群与原生生境的土壤理化性质、土壤酶活性及土壤微生物群落结构的相互关系。结果发现，影响紫羊茅、中亚薹草和野燕麦染菌率的主要因子是土壤水分含量和碳氮比，且土壤C、N、S以及土壤水分含量与紫羊茅的内生真菌染菌率成正相关，土壤蔗糖酶、脲酶和酸性磷酸酶与紫羊茅的感染率显著正相关，但中亚薹草与紫羊茅的结果相反。丝盖伞科是华北落叶松林和油松林土壤微生物群落的优势真菌，但不同染菌植被群落类型下的优势细菌微生物群落组成不同。总体看来，4种森林群落类型下禾草内生真菌染菌率与土壤理化性质相关性不同，且受到的生态因子影响大小也有差异，内生真菌感染导致各植被群落类型的土壤微生物群落结构具有差异，其优势土壤真菌和土壤细菌组成不同，这有助于进一步认识原生生境下不同感染率的禾草种群对土壤微生物群落结构的影响及其在生态系统中的各异生态学功能。 Abstract:Fungal endophytes are fungi that live for a significant part of their life cycle internally and asymptomatically (without causing any apparent tissue damage) in plants. For grasses, these endophytes are often specialized, systemic, and vertically transmitted. Pangquangou Nature Reserve is located in the middle of the of Luliang Mountain range. It was established for the conservation of the first-grade State protection animal, Crossoptilon mantchuricum, and the cold-temperate coniferous forest. It plays a significant role in water conservation, eco-tourism, biodiversity maintenance, and other functions in Pangquangou Nature Reserve. Many studies have been conducted; however few of them have examined the distribution and mechanism of fungal endophytes associated with common plants in Pangquangou Nature Reserve. In the present study, we assessed the endophyte infection rate of dominant plants in four different forest communities. Our objective was to investigate the effects of endophyte fungi association on soil properties, soil enzyme activity, and soil microbial communities in native habitats. We surveyed endophyte infection rates of four common plants (Festuca rubra, Avena fatua, Carex alexeenkoana, and Poa annua). We also analyzed the soil total carbon (C), total nitrogen (N), and total sulfur (S) with an Elemental Analyzer, and soil microbial community composition were assayed by using the high-throughput sequencing technique. Our results showed that soil water content and ratio of carbon and nitrogen were the main factors affecting the endophyte infection rates of Festuca rubra and Carex alexeenkoana, and the soil C, N, S and soil water content were positively correlated with the endophyte infection rate of Festuca rubra. There were strong positive correlations between soil invertase and endophyte infection rates of Festuca rubra, as well as urease and acid phosphatase. However, Carex alexeenkoana exhibited opposite results to those of Festuca rubra. Inocybaceae is the dominant fungi of soil microbial community in Larix principis-rupprechtii community, but had different bacterial compositions in soil microbial community under four forest communities. Overall, there were different correlations between fungal endophyte infection rate and soil properties under different communities, and the effects of ecological factors were also different. Endophyte fungal contributed to change soil microbial community structure, and led to varying soil fungi and bacteria compositions in different forest communities. Our findings can help with further understanding the distribution of fungal endophytes associated with common plants in native habitats and the influence of endophyte infected plants on soil microbial community structure and ecological functions in ecosystems. 参考文献 相似文献 引证文献

Effects of climate change on potential habitats of the cold temperate coniferous forest in Yunnan province, southwestern China

We built a classification tree (CT) model to estimate climatic factors controllingthe cold temperate coniferous forest (CTCF) distributions in Yunnan provinceand to predict its potential habitats under the current and future climates, using seven climate change scenarios, projected over the years of 2070-2099. The accurate CT model on CTCFs showed that minimum temperature of coldest month (TMW) was the overwhelmingly potent factor among the six climate variables.The areas of TMW<-4.05 were suitable habitats of CTCF, and the areas of -1.35 < TMW were non-habitats, where temperate conifer and broad-leaved mixed forests (TCBLFs) were distribute in lower elevation, bordering on the CTCF. Dominant species of Abies, Picea, and Larix in the CTCFs, are more tolerant to winter coldness than Tsuga and broad-leaved trees including deciduous broad-leaved Acer and Betula, evergreen broad-leavedCyclobalanopsisand Lithocarpus inTCBLFs. Winter coldness may actually limit the cool-side distributions of TCBLFs in the areas between -1.35°C and -4.05°C, and the warm-side distributions of CTCFs may be controlled by competition to the species of TCBLFs. Under future climate scenarios, the vulnerable area, where current potential (suitable + marginal) habitats (80,749km2) shift to non-habitats, was predicted to decrease to 55.91% (45,053 km2) of the current area.Inferring from the current vegetation distribution pattern, TCBLFs will replace declining CTCFs. Vulnerable areas predicted by models are important in determining priorityof ecosystem conservation.

The application of a binary division procedure to the classification of forest subcategories using MODIS time-series data during 2000–2010 in China

ABSTRACTForests account for more than 23% of China’s total area. As the most important terrestrial ecosystem, forests have tremendous ecological value. However, it remains difficult to classify forest subcategories at the national scale. In this study, a newly developed binary division procedure was used to categorize forest areas, including their spatiotemporal dynamics, during the period 2000–2010. Time-series images acquired using the Moderate Resolution Imaging Spectroradiometer (MODIS), together with auxiliary data on land use, climate zoning, and topography, were utilized. Hierarchical classification and zoning were combined with remote-sensing auto-classification. Based on the forest extent mask, the state-level forest system was divided into four classes and 18 subcategories. The method achieved an acceptable overall accuracy of 73.1%, based on a comparison to the sample points of China’s fourth forest general survey data set. In 2010, the total forest area was 1.755 × 106 km2, and the total area of and shrubs was 4.885 × 105 km2. The total area of woodland increased by 2536.25 km2 during the decade 2000–2010. The shrub subcategories exhibited almost no change during this time period; however, significant changes in forest area occurred in the mountainous region of Northeast China as well as in the hilly regions of Southern China. The main transformations took place in cold-temperate and temperate mountainous deciduous coniferous forest, subtropical deciduous coniferous forest, subtropical evergreen coniferous forest, and temperate and subtropical deciduous broadleaved mixed forests. The binary division procedure proposed herein can be used not only to rapidly classify more forest subcategories and monitor their dynamic changes, but also to improve the classification accuracy compared with global and national land-cover maps.

基于保护价值与保护成本分析的滇西北植被优先保护区识别

PDF HTML阅读 XML下载 导出引用 引用提醒 基于保护价值与保护成本分析的滇西北植被优先保护区识别 DOI: 10.5846/stxb201504040677 作者: 作者单位: 云南大学生态学与地植物学研究所,云南大学生态学与地植物学研究所,云南大学生态学与地植物学研究所,云南大学生态学与地植物学研究所,云南大学生态学与地植物学研究所,云南大学生态学与地植物学研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（41361046）；科技部国家科技支撑计划项目（2011BAC09B07）；中国科学院“西部之光”人才培养计划 Priority area identification for vegetation in northwest Yunnan, based on protection value and protection cost Author: Affiliation: Institute of Ecology and Geobotany, Yunnan University,Institute of Ecology and Geobotany, Yunnan University,Institute of Ecology and Geobotany, Yunnan University,Institute of Ecology and Geobotany, Yunnan University,Institute of Ecology and Geobotany, Yunnan University,Institute of Ecology and Geobotany, Yunnan University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:生物多样性丧失和保护资源不足是当前人类面临的严峻问题，确定保护等级和优先保护区是当前一项重要工作。以滇西北三江并流区为例，基于多准则决策分析方法（MCDA），以物种丰富度、植被稀有性、国家级濒危植物种数、省级濒危植物种数、濒危等级和生境特殊性6个因子为指标，对滇西北24种植被亚型进行保护价值评分。并融合海拔、距居民点距离、距道路距离、距河流距离4个人为干扰因子分析了保护成本。对保护价值和保护成本进行叠加分析确定研究区植被的保护等级以及优先保护区。结果表明：滇西北植被可分为4个保护等级，其中等级1作为优先保护区面积16983km2，占滇西北总面积25.58%，其主要保护的为季风常绿阔叶林，寒温性针叶林，高山、亚高山草甸，寒温性灌丛，积雪，水体这6类植被亚型；优先保护区作为综合的保护区能够对重要的森林、草地和湿地植被做到保护，等级2是作为森林保护主体区。等级3可作为保护缓冲区，等级4则作为传统的土地利用区。 Abstract:Biodiversity losing and unreasonable use of nature resources are two important environmental issues. In order to protect biodiversity rescources, many countries have established numerous nature reserves and other types of protected areas. However, degradation of natural resources is a big challenge in conservation projects, and we cannot prohibit all the activities associated with economic development in the conserved areas, particularly in southwest China. There is a serious conflict between two aspects. One aspect is the rich biodiversity, increasing its importance for conservation. The other is the backward economy that requires more resources for local development. Therefore, land zoning is an important approach that can reduce conflict by partitioning the landscape into various land use units that are managed according to different levels of human activity. Our research focuses on the Three Parallel Rivers of the Yunnan Protected Area. We present a systematic methodology that integrates vegetation plot data with Geographic Information Systems (GIS) using a multi-criteria decision analysis (MCDA) technique to guide a zoning scheme. The vegetation plot data include species richness, rarity of vegetation, number of endangered plant species, ranking of endangered species, and quality of habitat. Based on these data, the protection value scores for the sub-vegetation in northwest Yunnan were obtained. Then altitude, distance to villages, distance to roads and distance to rivers were used as the impact factors to simulate the pattern of protection cost. The protection value and protection cost were integrated to generate a final combined suitability map. A K-means cluster analysis was performed to classify the suitability map into four priority levels. In this study, the area considered under level 1 was 16983 km2, accounting for 25.58% of the total research area. The targeted areas for protection in level 1 included sub-vegetation of monsoon evergreen broad-leaved forest, cold-temperate coniferous forest, alpine and sub-alpine meadow, cold-temperate shrub, and areas covered by snow and water; level 1 accounts for the most important protection areas where important forest ecosystems, grassland ecosystems, and wetland ecosystems can be found. The areas under level 1 can be further divided into six parts. Part 1 is located northeast of Zhongdian; the average altitude is above 3000 m, and it is covered by cold-temperate coniferous forest. Part 2 comprises most areas of Denqing and northern Weixi, which include the Meili and Baima snowmountains. Part 3 forms the main part of the Nu mountains in Yunnan, and it appears as a line. Part 4 is located in Gongshan and Fugong, including the main part of Gaoligong National Nature Reserve. Part 5 comprises regions of southeast Zhongdian, northwest Ninglang, and northeast Lijiang. Although this part has a large area, its distribution is scattered. Part 6 comprises the Erhai Lake in Dali, which has a small area, and it is the only critical conservation region southeast of our research area. Level 2 accounts for the main areas for the conservation of forest ecosystems. Therefore, we suggested that an equal protection effort as level 1 should be made. Level 3 had a low protection value and we could use it as a buffer zone. Level 4 had no protection value and was considered the traditional land use area. According to the priority levels, we determined the area under level 1 as the priority area. We believe that our results will be useful as a reference for extension of reserves in northwest Yunnan in the future. 参考文献 相似文献 引证文献

Effects of nitrogen addition on soil inorganic N content and soil N mineralization of a cold-temperate coniferous forest in Great Xing'an Mountains

Nitrogen (N) plays an important role in carbon and nutrient cycling in forest ecosystems. Previous studies have shown that increased atmospheric N deposition has led to changes in forest soil N transfomations and soil N availability. However, knowledge gap exists about the impacts of N deposition on soil N dynamics of forest, especially for the boreal forests in China. In order to explore such impacts, a low-dose (Control, 0kgNhm−2years−1, Low N—10kgNhm−2years−1and High N, 40kgNhm−2years−1) and multiple forms (NH4Cl, KNO3 and NH4NO3) of simulated atmospheric N deposition experiment was conducted from 2010–2012 in a cold-temperate coniferous forest in the Great Xing'an Mountains. This paper reports inorganic N (NH4+-N and NO3−-N) content, net ammonification rate, net nitrification rate and net N mineralization rate in the 0–10cm mineral soil during the growing season from May to September in 2012, the third year after N addition. Results that during the growing season, soil inorganic N was dominated by NH4+-N, showing a significant seasonal variation. Soil NH4+-N and NO3−-N responded differently to exogenous N addition. Soil NH4+-N content was more affected by the forms of N addition, while soil NO3−-N content was more affected by the doses of N addition. Relative to control, NH4+-N content of 0–10cm mineral soil increased greatly with NH4+-N addition, which was completely different from the results observed in the first growing season of N addition in that no obvious effects of N addition on NH4+-N content of 0–10cm mineral soil was observed. In agreement with results observed in the growing season, NO3−-N content of 0–10cm mineral soil still showed a trend of enrichment with low dose N addition. For the N-limited forest ecosystem, soil net ammonification with a significant seasonal variation contributed most to soil net N mineralization, and soil net ammonification increased under NO3−-N addition, especially in the case of low dose N addition. Similar to soil net ammonification, soil net nitrification rates increased more under low-dose N addition compared to high-dose N addition. The possible explanation for our results is that a shift of 0–10cm mineral soil NH4+-N in response to N addition over time could be attributed to continue NH4+-N addition-induced increase of litterfall decomposition and decrease of microbial N immobilization and autotrophic nitrification due to a reduction in soil pH. Continual NO3−-N addition might decrease the number and activity of autotrophic nitrifying bacteria, showing a positive effect on net ammonification in the 0–10cm mineral soil. Compared with low doses of N addition, the effect of high doses of NH4+-N addition on soil acidification could be higher and high doses of NO3−-N addition might suppress the activity of nitrifying bacteria, increase the risk of leaching and denitrification, and stimulate microbial N immobilization in the N-poor soil. Our results, to some extent, suggest that increasing atmospheric N deposition will promote the accumulation of 0–10cm mineral soil NH4+-N and promote soil net N mineralization of the cold-temperate coniferous forest in Great Xing'an Mountains.

Low-Level Nitrogen Addition Promotes Net Methane Uptake in a Boreal Forest across the Great Xing'an Mountain Region, China

Chronic nitrogen (N) deposition may alter the amount and direction of methane (CH4) uptake in boreal forest soils, but the critical level of N deposition eliciting the alteration of soil CH4 uptake remains unknown. In a cold-temperate coniferous forest in the Great Xing' an Mountain of northeastern China, NH4NO3 fertilizer was added at four rates: control (0 kg N ha(-1) year(-1)), low N (10 kg N ha(-1) year(-1)), medium N (20 kg N ha' year(-1)), and high N (40 kg N ha(-1) year(-1)). Soil atmospheric CH4 fluxes as well as soil temperature, soil moisture, mineral N, dissolved organic carbon (DOC), and pH values were determined to explore the main factors controlling soil CH4 uptake fluxes under different N addition levels. Our results showed that N addition did not alter soil temperature, soil moisture, and soil NH4+-N concentrations. Low N rather than medium and high N significantly increased soil DOC and NO3--N concentrations in mineral horizon as well as soil CH4 uptake fluxes. In addition, soil acidification occurred in the fertilized forest soils, because soil pH declined by 0.4 unit. CH4 uptake in the cold-temperate forest soil was dominated by soil moisture followed by soil DOC and soil mineral N. Low N seemed to stimulate soil CH4 uptake through increasing the contents of soil DOC and NO3--N. These results suggest that low-level N addition (< 20 kg N ha-1 year(-1)) can promote CH4 uptake in the cold-temperate coniferous forest soil, which is also conducive to carbon sequestration of the boreal forests.

Vegetation history, climatic changes and Indian summer monsoon evolution during the Last Glaciation (36,400–13,400 cal yr BP) documented by sediments from Xingyun Lake, Yunnan, China

We obtained a 9.74-m-long sediment core (XY08A) from Xingyun Lake in central Yunnan Province, southwest China, and used AMS radiocarbon dating of terrestrial plant macrofossils to provide a chronology. Here we present the results of pollen and grain size analyses of the interval ~36,400–13,400calyr BP and discuss the vegetation history, and record of climate change associated with the evolution of the Indian summer monsoon (ISM). Three stages of regional vegetation change are documented: (i) During the late Marine Isotope Stage 3 (36,400–29,200calyr BP), the study region was occupied by mixed coniferous and evergreen broad-leaved forest dominated by Pinus and evergreen Quercus, with Tsuga, Abies/Picea growing on the surrounding mountains. (ii) During the Last Glacial Maximum (LGM, 29,200–17,600calyr BP), cold-temperate coniferous forest dominated by species of Abies/Picea expanded and reached a maximum extent; and at the same time, the extent of evergreen broadleaved forest increased. (iii) From 17,600 to 13,400calyr BP the hemlock forest and Abies/Picea forest began to decline until they disappeared completely in the early phase of the Last Deglaciation, while pine forest and evergreen broadleaved forest dominated the surrounding areas. The vegetation history indicates a generally drying climate from 36,400 to 13,400calyr BP, suggesting a gradual weakening of the ISM with the weakest ISM influence occurring during the early part of the Last Deglaciation, when the climate was the driest. The regional temperature first decreased intermittently and then increased gradually, being mild and wet during the late MIS3 stage followed by the coldest but not the driest climate during the LGM when the temperature was at least 3˚C lower than at present.