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1.
ABSTRACT

Climate change affects plant phenology, spatial distribution, and even extinction of vulnerable species. Dipterocarpus turbinatus, locally known as garjan, is a valuable but vulnerable native tree species of Bangladesh whose spatial distribution under future climate change scenarios is not fully understood. The aim of this study was to examine the effects of present and future climatic scenarios on spatiotemporal distribution of D. turbinatus. We used maximum entropy species distribution modeling to perform the present and future habitat suitability of garjan under different climate scenarios. The representative concentration pathways (RCP) 2.6 and 8.5 were considered for bioclimatic variables from the Global Climate Model – Hadley Global Environment Model 2 Atmosphere-Ocean. The predictive accuracy of the model was more than 97% in both the training and test data. The prediction results suggest that compared to present areas (7624 km2) under moderate habitat class it will be 2755 km2 and 1239 km2, respectively, in 2050 and 2070 under RCP2.6 scenario and decreases more rapidly under RCP8.5 scenario. Besides, the prediction also indicates that the habitat of the species will shift toward the high altitudinal south-eastern corner of the country whereas local extinction might occur in the north-eastern part during 2070.  相似文献   

2.
气候变化情景下河北省3个优势树种适宜分布区预测   总被引:2,自引:0,他引:2  
【目的】探究河北省3个优势树种分布与气候因子的关系,并进行适宜分布区预测,以期为评估气候变化的影响及制定适宜未来气候变化的森林经营策略提供理论依据。【方法】依据河北省森林资源调查数据,选取华北落叶松、蒙古栎和油松这3个主要树种,采用ClimateAP气候模型生成当前及未来(2040—2069年和2070—2099年)与降水和温度相关的10个气候因子,利用MaxEnt生态位模型和基于3个气候变化情景(温室气体最低排放,RCP2.6;中度稳定排放,RCP4.5;高度排放,RCP8.5)的一致性预测,模拟3个树种当前和未来的潜在适宜分布区,并采取响应曲线分析主要气候因子对3个树种适宜分布区的影响。【结果】3个树种MaxEnt模型的受试者工作特征曲线下面积(AUC值)都大于0.85,具有较好的预测能力;当前3个树种主要适宜分布在燕山和太行山地区;影响3个树种分布的主导气候因子存在差异,华北落叶松主要受小于0℃年积温和湿季降水量的影响,蒙古栎则主要受最热月平均气温、Hargreaves水分亏缺和湿季降水量的影响,而最热月平均气温、湿季降水量、大于5℃年积温和年均气温是影响油松分布的主要气候因子;一致性预测表明,在2040—2069年,河北省华北落叶松分布面积明显扩大,蒙古栎分布面积变化较小,而油松分布面积显著缩小;在2070—2099年,3个树种的适宜分布面积都显著缩小,幅度均超过3%。【结论】随着气候变化,3个树种均有向高海拔地区迁移的趋势,但在经纬度方向上的分布变化不大。在未来3个树种的适宜分布区,采取人工手段(如造林)辅助树种扩散以适应气候变化,有利于提高森林生产力,构建健康稳定的森林生态系统。  相似文献   

3.
为了研究气候变化情景下澳洲坚果在云南省的潜在适宜生境,采用当前和未来2050年RCP45气候变化情景下的19个生物气候因子及最大熵模型MaxEnt进行澳洲坚果生境模型构建,并进行适宜生境等级划分及空间变化特点分析。结果表明,2050年RCP45气候变化情景下3个等级的适宜生境大体上仍然保持与当前相似的空间分布格局,即高度适宜生境主要分布在云南西南部和南部,中、低度适宜生境分布在高度适宜生境区以北及以东区域。未来气候变化引起高度和中度适宜生境面积小幅度缩减(5.6%和2.4%),低度适宜生境面积增加22.5%。气候变化同时引起高度适宜生境景观格局破碎化。未来气候变化引起的澳洲坚果在云南高、中度适宜种植区总面积略有缩减,虽幅度不大,但空间分布上发生位移,且呈现破碎化趋势,产业规划时应考虑产业生命周期内气候变化造成对适宜生境迁移的影响。  相似文献   

4.
We studied how the use of certain tree species in forest regeneration affected the volume growth, timber yield, and carbon stock of boreal forests in Finland under the current climate (1981–2010) and recent-generation global climate model (GCM) predictions (i.e., multi-model means and individual GCMs of CMIP5), using the representative concentration pathways RCP4.5 and RCP8.5 over the period 2010–2099. Forest ecosystem model simulations were conducted on upland national forest inventory plots throughout Finland. In a baseline management regime, forest regeneration was performed by planting the same tree species that was dominant before the final cut. In alternative management regimes, either Scots pine, Norway spruce, or silver birch were planted on medium-fertility sites. Other management actions over rotation were done as in a baseline management. Compared to baseline management, an increased planting of birch resulted in relative sense highest increase in the volume growth, timber yield, and carbon stock in forests in the south, especially under severe climate projections (e.g., multi-model mean RCP8.5, and GCMs such as HadGEM2-ES RCP8.5 and GFDL-CM3 RCP8.5). This situation was opposite for Norway spruce. In the north, the volume growth, timber yield, and carbon stock of forests increased the most under severe climate projections (e.g., multi-model mean RCP8.5 and CNRM-CM5 RCP8.5), regardless of tree species preference. The magnitude of the climate change impacts depended largely on the geographical region and the severity of the climate projection. Increasing the cultivation of birch and Scots pine, as opposed to Norway spruce, could be recommended for the south. In the north, all three species could be cultivated, regardless of the severity of climate change.  相似文献   

5.
Yirdaw  Eshetu 《New Forests》2001,22(3):159-177
Woody species diversity and ground layervegetation cover were studied in plantations ofPinus patula, Cupressus lusitanica,Grevillea robusta, and Juniperusprocera, and in surrounding natural forests inWondo Genet, Ethiopia. In the understory of theplantations, a total of 53 naturallyregenerated tree and shrub species belonging to31 families were recorded. Important indigenoustimber species were also represented. Treesaccounted for 72% of all naturally-regeneratedwoody plant species. On the average, 78% ofthe woody species found in plantations werealso found in the natural forest. There was nosignificant variation in understory woodyspecies richness among plantations. C.lusitanica plantations had a significantlyhigher abundance of woody species than those ofP. patula, but the difference wasnot significant in relation to J. procera,G. robusta and the adjacent natural forest.The herbaceous ground cover percentage in G. robusta and P. patula stands wasconsiderably higher than in C. lusitanicaand J. procera stands. Relative toplantations of other species, plantations ofthe native tree species J. procera hadhigher understory species richness, mediumwoody species abundance and low ground cover.Although there was a marked variation inoverstory plantation density, its effect onunderstory species richness and abundance wasnot significant. The density ofnaturally-regenerated woody species inplantations was over three times the usualplanting density in Ethiopia, indicating a highpotential of forest plantations for restoringthe natural forest ecosystems on degraded landsat a comparatively low cost.  相似文献   

6.
《林业研究》2021,32(1)
African teak(Milicia excelsa(Welw.) C.C.Berg) is an endangered multi-use species.Understanding the impact of climate change on the distribution of this species may improve the ability to anticipate or recognize its decline or expansion and to take appropriate conservation measures if necessary.Ecological niche modeling was projected in geographical space to study the current and future distribution of M.excelsa in Benin.MaxEnt was used to estimate the potential geographic distribution of the species under two Representative Concentration Pathways(RCP).Miroc 5 summaries and two RCP 4.5 and RCP 8.5 scenarios were used as predictor variables for projections of the geographic potential of this species.The performance of the model was assessed by the area under the curve(AUC),true skill statistics(TSS) and partial receiver operating characteristics(Partial ROC).From the results,M.excelsa was more a secondary species in the Guinean climatic zone and part of the Sudanian-Guinean and Sudanian climatic zone.The projections show a significant decrease in suitable habitats for the species from the two RCP scenarios.Only a part of the Guinean climatic zone remained suitable and few protected areas will conserve in situ M.excelsa.For the sustainable conservation of M.excelsa,it is essential to strengthen the protection of sacred forests located in the Guinean climatic zone.  相似文献   

7.
流苏香竹(Chimonocalamus fimbriatus)是云南特有珍稀竹种,主要分布于云南西南部。文章以野外调查获取的流苏香竹分布信息为主,运用最大熵模型(MaxEnt)同时结合地理信息系统(ArcGIS),基于19个气候因子,预测其在当前及未来气候变化情景下的潜在分布区。结果表明:当前流苏香竹的高适生区和中适生区主要分布于德宏州、保山市和临沧市等地,除迪庆州、丽江市和昭通市外,云南其他区域均有低适生区零星分布。在未来2050s和2070s的2个时间段,基于2种不同共享社会经济路径(SSP1-2.6和SSP5-8.5),流苏香竹的高适生区面积呈减少的趋势,尤其是SSP5-8.5路径下,高适生区面积仅为当前的12.51%(2050s)和18.63%(2070s);中、低适生区在SSP1-2.6路径下,显著扩张(2050s)或略微扩张(2070s),在SSP5-8.5路径下,则大幅收缩。流苏香竹野外实际分布区及其潜在分布区均以斑块状为主,可能与云南特殊的地形、地貌有关。影响流苏香竹分布的主导气候因子为最湿月份降水量、最暖月份最高温度、最干季度降水量和平均气温日较差。流苏香竹对气候变化比较敏感,根据其野外分布状况,建议以就地保护为主、迁地保护为辅,在其潜在适生区内适当引种栽培。  相似文献   

8.
Daxing'anling is a key region for forest fire prevention in China.Assessing changes in fire risk in the future under multiple climatic scenarios will contribute to our understanding of the influences of climate change for the region and provide a reference for applying adaptive measures for fire management.This study analyzed the changes in fire weather indices and the fire season under four climate scenarios(RCP2.6,RCP4.5,RCP6.0,RCP8.5)for 2021–2050 using data from five global climate models together with observation data.The results showed that the analog data could project the average state of the climate for a given period but were not effective for simulating extreme weather conditions.Compared with the baseline period(1971–2000),the period 2021–2050 was predicted to have an increase in average temperature of 2.02–2.65 °C and in annual precipitation 25.4–40.3 mm,while the fire weather index(FWI) was predicted to increase by6.2–11.2% and seasonal severity rating(SSR) by5.5–17.2%.The DMC(Duff moisture code),ISI(initial spread index),BUI(build-up index),FWI and SSR were predicted to increase significantly under scenarios RCP4.5,RCP6.0,and RCP8.5.Furthermore,days with high or higher fire danger rating were predicted to be prolonged by 3–6 days,with the change in the southern region being greater under scenarios RCP4.5,RCP6.0,and RCP8.5.  相似文献   

9.
We modeled and mapped, using the predictive data mining tool Random Forests, 134 tree species from the eastern United States for potential response to several scenarios of climate change. Each species was modeled individually to show current and potential future habitats according to two emission scenarios (high emissions on current trajectory and reasonable conservation of energy implemented) and three climate models: the Parallel Climate Model, the Hadley CM3 model, and the Geophysical Fluid Dynamics Laboratory model. Since we model potential suitable habitats of species, our results should not be interpreted as actual changes in ranges of the species. We also evaluated both emission scenarios under an “average” future climate from all three models. Climate change could have large impacts on suitable habitat for tree species in the eastern United States, especially under a high emissions trajectory. Of the 134 species, approximately 66 species would gain and 54 species would lose at least 10% of their suitable habitat under climate change. A lower emission pathway would result in lower numbers of both losers and gainers. When the mean centers, i.e. center of gravity, of current and potential future habitat are evaluated, most of the species habitat moves generally northeast, up to 800 km in the hottest scenario and highest emissions trajectory. The models suggest a retreat of the spruce-fir zone and an advance of the southern oaks and pines. In any case, our results show that species will have a lot less pressure to move their suitable habitats if we follow the path of lower emissions of greenhouse gases. The information contained in this paper, and much more, is detailed on our website: http://www.nrs.fs.fed.us/atlas.  相似文献   

10.
The objective of this study was to identify climatic factors determining the distribution of a keystone understory taxon, section Crassinodi of the genus Sasa, and assess the impacts of climate change on the taxon. Relationships between the distribution of sect. Crassinodi and five climatic variables were explored using classification tree analysis. Potential habitats under current climate and future climate in 2081–2100 were predicted. Potential habitats were further divided into suitable and marginal habitats. The predictive accuracy of the model was assessed using receiver operating characteristic analysis and by comparing model predictions with an independent dataset. The model was reasonably accurate. It showed that the warmth index (WI) and snow cover were the most important climatic variables for Crassinodi distribution. Potential habitats were limited to cooler regions with WI <102.7°C month. Suitable habitats were limited to even cooler regions with WI <84.8°C month. The model also showed that areas with deeper snow than previously reported would provide suitable habitats for Crassinodi under some climatic conditions. In 2081–2100, 37.4% of current potential habitats are predicted to become non-habitats because of increases in WI. Most currently suitable habitats are predicted to vanish from western Japan by 2081–2100. Meanwhile, Hokkaido and high-elevation areas of eastern Honshu will sustain suitable habitats. Sect. Crassinodi, which is adapted to less snowy climates, is predicted to be more affected by climate change than sect. Sasa and Macrochlamys, which are adapted to snowy climates.  相似文献   

11.
基于MaxEnt模型的毛红椿适生区预测   总被引:1,自引:0,他引:1       下载免费PDF全文
[目的]了解环境因子对毛红椿适生区分布的影响,为其资源保护、引种及其人工林的发展提供参考。[方法]基于MaxEnt模型能利用现存不完整、小样本、离散型分布数据构建物种适生区预测模型,用受试者工作曲线线下面积(AUC)检验预测模型的精度,面积越大精度越高等优点,本研究应用毛红椿在云南的分布数据及1个地型因子和6个气候因子,来构建其适生区分布模型。[结果]毛红椿适生区分布MaxEnt模型平均训练AUC和平均测试AUC分别为0.891、0.885,说明对毛红椿适生区的预测是可靠的;降水量变异系数和最干季度降水量是决定毛红椿适生区分布的主要因子,年均气温变化范围、最冷季度平均气温、最湿季度降水量、最冷季度降水量是次要因子。在当代和未来(2050S、2070S)气候变暖条件下(RCP2.6情景),云南省和全国适生区面积计算结果直观、定量的反应了全球变暖对毛红椿适生区变迁的影响。[结论]预测云南省及全国的毛红椿适生区随全球变暖而小幅萎缩。  相似文献   

12.

? Introduction

Information on spatial variability in tree radial growth is essential for improving predictions of forest ecosystem responses to climate change. To date, researchers have designed models to simulate the potential distribution area of major forest types under different climate change scenarios in Northeast China, but little is known about the spatial variability of tree growth in response to climate.

? Materials and methods

We used a dendroecological technique to examine the climate–growth relationship of six dominant tree species on seven sites varying in altitude on Changbai Mountain in Northeast China, to explore whether the spatial variability of tree growth is an indicator of regional climatic forces, and whether simulation results generated by models can accurately reflect this in tree radial growth.

? Results

Fifteen site-specific species can be distinguished species at or near their upper limit distribution from those at the lower distributions. Species differences were more important than altitude differences in influencing species’ site-specific radial growth. Precipitation, temperature, and soil moisture together constitute the major factors limiting tree radial growth.

? Conclusion

We found the distribution area of dominant tree species on Changbai Mountain will shift upward; growth of Korean pine will not decline at its lower limit of distribution and will not eventually even disappear from forest communities in those areas.  相似文献   

13.
The effect of six plantation species in comparison to natural forest (NF) on soil organic carbon (SOC) and total nitrogen (TN) stocks, depth-wise distribution, biomass carbon (C), and N was investigated on plantations and cultivated lands on an Andic paleudalf soil in Southern Ethiopia. The SOC, N, and bulk density were determined from samples taken in 4 replicates from 10-, 20-, 40-, 60-, and 100-cm depth under each site. Similarly, the biomass C and N of the plantation species and understory vegetation were also determined. The SOC and N were concentrated in the 0- to 10-cm depth and decreased progressively to the 1-m depth. Next to the NF, Juniperous procera accrued higher SOC and N in all depths than the corresponding plantations. No evidence of significant difference on SOC and N distribution among plantations was observed below the 10-cm depth with minor exceptions. The plantations accrue from 133.62 to 213.73 Mg ha–1 or 59.1 to 94.5% SOC, 230.4 to 497.3 Mg ha–1 or 6.9 to 14.9% TBC and 420.37 to 672.80 Mg ha–1 or 12.5 to 20% total C-pool of that under the NF. The N stock under Juniperous procera was the highest, while the lowest was under Eucalyptus globulus and Cupressus lusitanica. We suggest that SOC and N sequestration can be enhanced through mixed cropping and because the performance of the native species Juniperous procera is encouraging, it should be planted to restock its habitat.  相似文献   

14.
Global climate change could have profound effects on the Earth’s biota, including large redistributions of tree species and forest types. We used DISTRIB, a deterministic regression tree analysis model, to examine environmental drivers related to current forest-species distributions and then model potential suitable habitat under five climate change scenarios associated with a doubling of atmospheric CO2. Potential shifts in suitable habitat for 76 common tree species in the eastern US were evaluated based on more than 100,000 plots and 33 environmental variables related to climate, soils, land use, and elevation. Regression tree analysis was used to devise prediction rules from current species–environment relationships. These rules were used to replicate the current distribution and predict the potential suitable habitat for more than 2100 counties east of the 100th meridian. The calculation of an importance value-weighted area score, averaged across the five climate scenarios, allowed comparison among species for their overall potential to be affected by climate change. When this score was averaged across all five climate scenarios, 34 tree species were projected to expand by at least 10%, while 31 species could decrease by at least 10%. Several species (Populus tremuloides, P. grandidentata, Acer saccharum, Betula papyrifera, Thuja occidentalis) could have their suitable habitat extirpated from US. Depending on the scenario, the optimum latitude of suitable habitat moved north more than 20 km for 38–47 species, including 8–27 species more than 200 km or into Canada. Although the five scenarios were in general agreement with respect to the overall tendencies in potential future suitable habitat, significant variations occurred in the amount of potential movement in many of the species. The five scenarios were ranked for their severity on potential tree habitat changes. Actual species redistributions, within the suitable habitat modeled here, will be controlled by migration rates through fragmented landscapes, as well as human manipulations.  相似文献   

15.
To quantitatively assess future change of evergreen broad-leaved tree species’ distributions in human-disturbed landscapes of the Korean Peninsula under climate change, potential habitats (PHs) were projected for four important evergreen broad-leaved tree species (Quercus acuta, Castanopsis sieboldii, Machilus thunbergii, and Neolitsea sericea) by species distribution models (SDMs). The distribution data (presence/absence) of the target species in Korea and Japan were used as response variables for SDMs, and climatic data were used as explanatory variables. Three general circulation models under A2 emission scenarios were used as future climate scenarios for the years 2070–2099. Potential habitats masked by land-use data (PHLUs) were projected to assess the impact of anthropogenic activities. Highly accurate SDMs were obtained for all the target species. The current PHs were decreased to 21–35 % by the anthropogenic activities. Future PHLUs for all the target species were projected to increase by 2.0–18.5 times of current PHLUs. These results suggest that all the target species are applicable as indicator species for monitoring in the Korean Peninsula, even if anthropogenic effects are incorporated. Variation of the increasing rate was caused by the differences in the response to temperature changes. M. thunbergii responded sensitively to the increase of minimum temperature of coldest month and had a largest increase in PHLUs under future climate. Therefore, M. thunbergii is considered to be most appropriate species for monitoring the changes of horizontal distributions above all focal evergreen broad-leaved tree species.  相似文献   

16.
Ten exotic Abies species were tested in two field trials, where the aim was to find suitable species and provenances for Christmas tree production in coastal and fjord areas in Norway. The material included 14 provenances of Abies nordmanniana, 3 provenances of Abies bornmuelleriana, 3 provenances of Abies koreana, 2 provenances of Abies amabilis, and 1 provenance each of Abies equi-trojani, Abies alba, Abies procera, Abies homolepis, Abies nephrolepis, and Abies forrestii. Field trials were established at Gulen in Sogn og Fjordane County and at Verdal in Nord-Trøndelag County. Christmas tree classification was done seven and eight growing seasons after establishment. The Christmas tree yield was higher in Gulen (64%) than in Verdal (45%), which is situated further north. Also, the survival and the height growth were higher in Gulen than in Verdal. A more humid climate and a longer growth season in Gulen may explain some of the differences. Of the 10 species, A. nordmanniana, A. homolepis, and A. bornmuelleriana produced the highest Christmas tree yield at Gulen, while A. homolepis and A. koreana had the highest yield at Verdal. Due to early bud burst, A. equi-trojani and A. bornmuelleriana are only suited for Christmas tree growing in the best climatic areas.  相似文献   

17.
基于MaxEnt模型新疆枣潜在适生区预测   总被引:1,自引:0,他引:1  
【目的】研究全球气候变化对新疆枣潜在分布的影响,划分新疆枣不同等级的适生区,为新疆枣产业的持续稳定发展提供参考。【方法】基于新疆枣地理分布的调查数据和2种气候情景(RCP4.5和RCP8.5),利用GIS技术和MaxEnt生态位模型相结合的方法,在全球气候变化背景下,对新疆枣的当前及未来(2050和2070年)潜在适生区分布进行预测。【结果】在当前气候条件下,新疆枣适生区主要分布在南疆和东疆地区。其中适生区总面积达到11.3×10~4 km^2,占新疆土地总面积的6.8%。采用受试者工作特征曲线(ROC曲线)对MaxEnt模型预测结果进行评价,结果显示训练数据集和测试数据集的曲线下的面积值(AUC值)分别为0.988和0.978,说明模型预测结果较为理想。刀切法分析结果显示,影响新疆枣当前分布的气候因子主要为最热月最高温度、最冷月最低温度、最暖季度均温、最冷季度均温、6月最高气温、7月最高气温、8月最高气温、12月最低气温、1月最低气温和2月最低气温。在未来气候条件下,新疆枣适生区面积有着一定的增加,但适生区的区域变化较小。【结论】Maxent模型预测结果与新疆枣的实际分布重合度较高。低温是影响新疆枣潜在适生区分布的重要因素。在全球气候变暖的趋势下,新疆枣整个潜在适生区面积呈现增加的特点且有向高纬度区域迁移的趋势,北疆地区开始出现较少部分的低适生区。  相似文献   

18.

We examined the association between habitat variables and the relative impacts of topographic microclimates as a valuable tool for restoration and conservation of Abies pinsapo in southern Spain. We used presence–absence data from A. pinsapo and 79 environmental variables and biomod species distribution models to describe the current and future species habitat across the Sierra de las Nieves Natural Park (southern Spain). A. pinsapo habitat was most strongly associated with microtopographic (solar incidence) and temperature variables, indicating climate-driven changes in microhabitat use. Most of the temperature variation among the study site was attributable to topographic microclimates rather than regional temperature differences, such that differences in microhabitat associations occurred principally between north- and south-facing slopes within the same region. The current potential distribution suggests that around 8.7% (56.44 km2) of the study area is highly suitable for A. pinsapo, with 9.7% (62.84 km2) being moderately suitable. Under different global circulation models and climate change scenarios, the net decrease in suitable habitat is predicted to be 93% of the current distribution by 2040, disappearing altogether by 2099. Our findings also show a sharp reduction of potential restoration areas (1.8% of the current areas). Microclimatic variation generated by the topography offers the microclimate-driven locations of habitat suitability which could shape species’ distribution restoration actions and their responses to environmental change. The approach presented here can provide a rapid assessment of the future conservation status of other important forest tree species in Spain, improving our understanding of the vulnerability of endangered species under climate change, and can be an effective tool for biodiversity conservation, restoration, and management.

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19.
The seedling establishment of Juniperus procera Hochst. ex Endl. and Afrocarpus gracilior (Pilger) C. N. Page was assessed in the Afromontane forests of Ethiopia. Percent light transmission, litter depth and percentage cover of vegetation were assessed for seedling microsites in five sites with different levels and history of disturbance. The response of natural and artificial regeneration to burning, mechanical scarification (removal of all logging waste and ground vegetation) and cultivation following clear felling and timber extraction was assessed 19 months after treatment.There was no evidence that regeneration was correlated with light intensity. Despite the presence of a viable seed bank in the undisturbed forest floor, removal of the overstorey vegetation by clear felling did not encourage natural regeneration of J. procera. This suggests that light may not be the main factor limiting regeneration of J. procera.Natural regeneration of J. procera can withstand exposure and is compatible with management by ‘clear cutting with seeding from adjacent stands’ together with ground treatment, particularly controlled burning which exposes the minearl soil and releases nutrients. In contrast, both clear felling and surface disturbance will discourage the natural (or artificial) regeneration of A. gracilior suggesting that J. procera is a pioneer species which is more exposure-tolerant, whilst A. gracilior is more shade-tolerant and exposure-intolerant.  相似文献   

20.

Key message

A climate-sensitive aboveground biomass (AGB) equation, in combination with nonlinear mixed-effects modeling and dummy variable approach, was developed to examine how climate change may affect the allometric relationships between tree diameter and biomass. We showed that such changes in allometry need to be taken into account for estimating tree AGB in Masson pine.

Context

As a native species and being widely distributed in subtropical China, Masson pine (Pinus massoniana Lamb.) forests play a pivotal role in maintaining forest ecosystem functions and mitigation of carbon concentration increase at the atmosphere. Traditional biomass allometric equations do not account for a potential effect of climate on the diameter–biomass relationships. The amplitude of such an effect remains poorly documented.

Aims

We presented a novel method for detecting the long-term (2041–2080) effects of climate change on the diameter–biomass relationships and the potential consequences for long-term changes of biomass accumulation for Masson pine.

Methods

Our approach was based on a climate-sensitive AGB model developed using a combined nonlinear mixed-effects model and dummy variable approach. Various climate-related variables were evaluated for their contributions to model improvement. Heteroscedasticity was accounted for by three residual variance functions: exponential function, power function, and constant plus function.

Results

The results showed that diameter at breast height, together with the long-term average of growing season temperature, total growing season precipitation, mean temperature of wettest quarter, and precipitation of wettest quarter, had significant effects on values of AGB. Excessive rain during the growing season and high mean temperature in the wettest quarter reduced the AGB, while a warm growing season and abundant precipitation in the wettest quarter increased the AGB.

Conclusion

Climate change significantly affected the allometric scale of biomass equation. The new climate-sensitive allometric model developed in this study may improve biomass predictions compared with the traditional model without climate effects. Our findings suggested that the AGB of Masson pine trees with the same diameter at breast height under three climate scenarios including representative concentration pathway (RCP) 2.6, RCP 4.5, and RCP 8.5 in the future period 2041–2080 would increase by 24.8 ± 32.7% (mean ± standard deviation), 27.0 ± 33.4%, and 27.7 ± 33.8% compared with the constant climate (1950–2000), respectively. As a consequence, we may expect a significant regional variability and uncertainty in biomass estimates under climate change.
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