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基于MODIS2000~2005(缺2004年)5a每8d的GPP资料,分析了中国陆地植被生长特征,讨论了我国气候因子(温度、降水以及辐射)对同期植被生长的影响。研究结果显示,中国陆地植被的年均GPP分布范围在0~3252.6gC.m-.2a-1之间,5a平均值为491.1gC.m-.2a-1;年均GPP最大的地方主要分布于云南南部、海南、台湾以及东南沿海部分地区,最小值主要出现在青藏高原、新疆以及内蒙古西部等高寒、干旱地区。温度是影响同期我国陆地植被生长的主要因子,其次为降水,辐射对我国陆地植被的影响比较小,主要影响区域在华南地区。陆地植被GPP与温度和降水的相关系数在我国表现为自北向南逐渐减小的分布特征,与对应气候因子的分布呈反向关系;而GPP与云量的相关系数则自北向南逐渐增大。 相似文献
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吉林省西部草地NPP时空特征与影响因素 总被引：4，自引：0，他引：4
利用2000--2006年MOD17A3数据集的年均NPP数据,通过GIS技术定量分析了吉林省西部草地NPP的时空变化特征及其自然和人文影响因素.结果表明:过去7年吉林省西部草地NPP平均值为232.14 g C·m~(-2)·a~(-1),NPP在200～300 g C·m~(-2)·a~(-1)的草地面积占草地总面积的59.47%;77.60%的草地NPP呈增加趋势,NPP增加极显著的草地面积占草地总面积的15.00%;水分条件是吉林省西部草地生长的主要控制因素;居民地对吉林省西部草地NPP的影响远大于道路,尤其在2 km以内.Abstract： By using the annual net primary productivity (NPP) data from 2000-2006 MOD17A3 dataset and the GIS technique, the spatiotemporal characteristics of grassland NPP in western Ji-lin Province were studied, with the related affecting factors analyzed. During the past seven years, the mean grassland NPP in this province was 232. 14 g C·m~(-2)·a~(-1), and the grassland area with a NPP of 200-300 g C·m~(-2)·a~(-1) accounted for 59. 47% of the total. 77.60% of the grassland had an increasing NPP, and the grassland area with a remarkable increase of NPP accounted for 15.00% of the total. Water condition was the main controlling factor for grass growth, and residential points had far more effects than roads, especially within 2 km from grass-land, on the NPP. 相似文献
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Aims Root and heterotrophic respiration may respond differently to environmental variability, but little evidence is available from large-scale observations. Here we aimed to examine variations of root and heterotrophic respiration across broad geographic, climatic, soil and biotic gradients.Methods We conducted a synthesis of 59 field measurements on root and heterotrophic respiration across China's forests.Important findings Root and heterotrophic respiration varied differently with forest types, of which evergreen broadleaf forest was significantly different from those in other forest types on heterotrophic respiration but without statistically significant differences on root respiration. The results also indicated that root and heterotrophic respiration exhibited similar trends along gradients of precipitation, soil organic carbon and satellite-indicated vegetation growth. However, they exhibited different relationships with temperature: root respiration exhibited bimodal patterns along the temperature gradient, while heterotrophic respiration increased monotonically with temperature. Moreover, they showed different relationships with MOD17 GPP, with increasing trend observed for root respiration whereas insignificant change for heterotrophic respiration. In addition, root and heterotrophic respiration exhibited different changes along the age sequence, with insignificant change for root respiration and decreasing trend for heterotrophic respiration. Overall, these results suggest that root and heterotrophic respiration may respond differently to environmental variability. Our findings could advance our understanding on the different environmental controls of root and heterotrophic respiration and also improve our ability to predict soil CO2 flux under a changing environment. 相似文献
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为了研究中国陆地植物细根碳(C)、氮(N)、磷(P)的空间变化模式,揭示细根在\"温度-植物生理假说\"及\"生长速率假说\"等方面的规律,该文收集已发表的有关中国陆地植物细根研究的文献,从中提取细根C、N、P元素含量及其相关数据,分析了细根C、N、P含量及其比例与经纬度之间的关系。结果表明:细根N、P元素含量均随纬度增加而增加,P含量随经度增加而降低,N:P随经度增加而增加。细根N、P含量与年平均气温、年降水量均呈负相关关系,与土壤养分呈正相关关系。在土壤养分、温度、降水量3个非生物因素中,土壤养分对细根N、P含量的影响最大。该文中细根和粗根的C:P、N:P差异变化不完全支持\"生长速率假说\"。根系和叶片一样,N、P含量与纬度呈正相关关系,支持\"温度-植物生理假说\",反映了植物对自然环境的适应策略。 相似文献
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The characteristics of terrestrial growth in China and its relationship with various climatic factors (e.g. temperature, precipitation and radiation) were investigated by using the data collected with the Moderate Resolution Imaging Spectroradiometer (MODIS). These data were collected once every 8 days during 2000–2003 and then again in 2005. The average annual gross primary production (GPP) in China during this period ranged from 0 to 3252.6 gC·m?2·a?1 with an average value of 491.1 gC·m?2·a?1. The maximum GPP values were observed over the regions of Yunnan, Hainan and Taiwan, and the southeast coastal areas, while the minimum values were observed in the cold and arid regions of the Tibetan Plateau, Xinjiang and Inner Mongolia. Correlation analysis showed that temperature was the primary factor influencing this terrestrial growth, while precipitation played a secondary role. However, only the terrestrial growth that occurred in southern China was affected by radiation. The correlation coefficients of GPP with temperature and precipitation decreased from northern to southern China and were negatively correlated with the distribution of the associated climatic factors within China. Furthermore, the correlation coefficient of GPP with cloud contents was observed to increase from northern to southern China. 相似文献
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The characteristics of terrestrial growth in China and its relationship with various climatic factors (e.g. temperature, precipitation and radiation) were investigated by using the data collected with the Moderate Resolution Imaging Spectroradiometer (MODIS). These data were collected once every 8 days during 2000–2003 and then again in 2005. The average annual gross primary production (GPP) in China during this period ranged from 0 to 3252.6 gC·m?2·a?1 with an average value of 491.1 gC·m?2·a?1. The maximum GPP values were observed over the regions of Yunnan, Hainan and Taiwan, and the southeast coastal areas, while the minimum values were observed in the cold and arid regions of the Tibetan Plateau, Xinjiang and Inner Mongolia. Correlation analysis showed that temperature was the primary factor influencing this terrestrial growth, while precipitation played a secondary role. However, only the terrestrial growth that occurred in southern China was affected by radiation. The correlation coefficients of GPP with temperature and precipitation decreased from northern to southern China and were negatively correlated with the distribution of the associated climatic factors within China. Furthermore, the correlation coefficient of GPP with cloud contents was observed to increase from northern to southern China. 相似文献
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地理、地形因素是影响西北旱寒区农业种植结构和生态保育的重要因素之一。以甘肃为例,在遥感和GIS技术支持下,选取该地区122个气象站点的1980、1990、2000年3个年份各月降雨量和平均气温作为数据源,分析了各月降雨量和平均气温与经纬度、海拔、坡向、坡度之间的相关关系。结果表明,降雨量与经度、纬度和海拔3个地理、地形因子相关性较大,与坡度和坡向无显著性相关;降雨量和纬度之间存在普遍的显著性负相关,平均偏相关系数在0.5以上。另外,月平均气温与经度、海拔具有很高的显著性负相关,其中平均气温与海拔之间的偏相关系数达到0.9以上,但与坡度和坡向的相关性不显著。更进一步,分析了3个年度各月的月平均气温与纬度之间的关系,虽然气温和纬度之间存在一定的相关性,但随着年份的变化,温度与纬度具有显著性相关的月份数在减少,并且在存在相关性的月份中,气温同纬度之间的偏相关系数也在逐年减小,纬度对温度的空间分布的影响正逐渐变弱。研究结果支持了中国西北干旱区范围正向东南扩展的结论,并为全球变化下旱区农业生态系统管理提供理论潜力。 相似文献
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为了研究中国陆地植物细根碳(C)、氮(N)、磷(P)的空间变化模式, 揭示细根在“温度-植物生理假说”及“生长速率假说”等方面的规律, 该文收集已发表的有关中国陆地植物细根研究的文献, 从中提取细根C、N、P元素含量及其相关数据, 分析了细根C、N、P含量及其比例与经纬度之间的关系。结果表明: 细根N、P元素含量均随纬度增加而增加, P含量随经度增加而降低, N:P随经度增加而增加。细根N、P含量与年平均气温、年降水量均呈负相关关系, 与土壤养分呈正相关关系。在土壤养分、温度、降水量3个非生物因素中, 土壤养分对细根N、P含量的影响最大。该文中细根和粗根的C:P、N:P差异变化不完全支持“生长速率假说”。根系和叶片一样, N、P含量与纬度呈正相关关系, 支持“温度-植物生理假说”, 反映了植物对自然环境的适应策略。 相似文献
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长时间序列的陆地碳通量数据在全球生态环境变化研究中具有重要意义。采用MODIS GPP(Gross Primary Productivity)算法,基于GIMMS LAI3g,MODIS15和Improved-MODIS15三种叶面积指数(LAI),估算了全球2000至2010年的植被总初级生产力(GPP)。该估算的GPP数值经过全球20个通量站点的验证,并结合MODIS17分析了它们在时空变化上的异同。结果表明:(1)4种GPP精度如下:GPP_(MOD17)GPP_(impro_MOD15)GPP_(LAI3g)GPP_(MOD15)。(2)4种GPP整体上具有一致的季节波动,冬季和夏季整体好于春季和秋季。GPP_(LAI3g)的4个季节精度较相近,而GPP_(MOD17)除了春秋季外其它季节都较好。(3)GPP_(LAI3g)在中等GPP值分布区的估值相对较高,其全球总GPP大体为(117±1.5)Pg C/a,GPP_(MOD17)和GPP_(impro_MOD15)相近且都低于该值。(4)GPP_(LAI3g)和GPP_(impro_MOD15)在大约63.29%的陆面上呈显著(P0.05)的正相关关系,它们和GPP_(MOD17)在LAI不确定性小的地区呈显著的正相关关系。GPP_(LAI3g)和GPP_(MOD15)正相关分布面积占比为40.61%。 相似文献
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Xoaquín Moreira Kailen A. Mooney Sergio Rasmann William K. Petry Amparo Carrillo‐Gavilán Rafael Zas Luis Sampedro 《Ecology letters》2014,17(5):537-546
There is increasing evidence that geographic and climatic clines drive the patterns of plant defence allocation and defensive strategies. We quantified early growth rate and both constitutive and inducible chemical defences of 18 Pinaceae species in a common greenhouse environment and assessed their defensive allocation with respect to each species' range across climatic gradients spanning 31o latitude and 2300 m elevation. Constitutive defences traded‐off with induced defences, and these defensive strategies were associated with growth rate such that slow‐growing species invested more in constitutive defence, whereas fast‐growing species invested more in inducible defence. The position of each pine species along this trade‐off axis was in turn associated with geography; moving poleward and to higher elevations, growth rate and inducible defences decreased, while constitutive defence increased. These geographic patterns in plant defence were most strongly associated with variation in temperature. Climatic and geographical clines thus act as drivers of defence profiles by mediating the constraints imposed by trade‐offs, and this dynamic underlays global patterns of defence allocation. 相似文献
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Aim To develop and test a simple climate‐based ecophysiological model of above‐ground biomass – an approach that can be applied directly to predicting the effects of climate change on forest carbon stores. Location Humid lowland forests world‐wide. Methods We developed a new approach to modelling the aboveground biomass of old‐growth forest (AGBmax) based on the influences of temperature on gross primary productivity (GPP) and what we call total maintenance cost (TMC), which includes autotrophic respiration as well as leaf, stem and other plant construction required to maintain biomass. We parameterized the models with measured carbon fluxes and tested them by comparing predicted AGBmax with measured AGB for another 109 old‐growth sites. Results Our models explained 57% of the variation in GPP across 95 sites and 79% of the variation in TMC across 17 sites. According to the best‐fit models, the ratio of GPP to maintenance cost per unit biomass (MCB) peaks at 16.5 °C, indicating that this is the air temperature leading to the highest possible AGBmax when temperatures are constant. Seasonal temperature variation generally reduces predicted AGBmax, and thus maritime temperate climates are predicted to have the highest AGBmax. The shift in temperatures from temperate maritime to tropical climates increases MCB more than GPP, and thus decreases AGBmax. Overall, our model explains exactly 50% of the variation in AGB among humid lowland old‐growth forests. Main conclusions Temperature plays an important role in explaining global variation in biomass among humid lowland old‐growth forests, a role that can be understood in terms of the dual effects of temperature on GPP and TMC. Our simple model captures these influences, and could be an important tool for predicting the effects of climate change on forest carbon stores. 相似文献
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Xiaohui Feng María Uriarte Grizelle González Sasha Reed Jill Thompson Jess K. Zimmerman Lora Murphy 《Global Change Biology》2018,24(1):e213-e232
Tropical forests play a critical role in carbon and water cycles at a global scale. Rapid climate change is anticipated in tropical regions over the coming decades and, under a warmer and drier climate, tropical forests are likely to be net sources of carbon rather than sinks. However, our understanding of tropical forest response and feedback to climate change is very limited. Efforts to model climate change impacts on carbon fluxes in tropical forests have not reached a consensus. Here, we use the Ecosystem Demography model (ED2) to predict carbon fluxes of a Puerto Rican tropical forest under realistic climate change scenarios. We parameterized ED2 with species‐specific tree physiological data using the Predictive Ecosystem Analyzer workflow and projected the fate of this ecosystem under five future climate scenarios. The model successfully captured interannual variability in the dynamics of this tropical forest. Model predictions closely followed observed values across a wide range of metrics including aboveground biomass, tree diameter growth, tree size class distributions, and leaf area index. Under a future warming and drying climate scenario, the model predicted reductions in carbon storage and tree growth, together with large shifts in forest community composition and structure. Such rapid changes in climate led the forest to transition from a sink to a source of carbon. Growth respiration and root allocation parameters were responsible for the highest fraction of predictive uncertainty in modeled biomass, highlighting the need to target these processes in future data collection. Our study is the first effort to rely on Bayesian model calibration and synthesis to elucidate the key physiological parameters that drive uncertainty in tropical forests responses to climatic change. We propose a new path forward for model‐data synthesis that can substantially reduce uncertainty in our ability to model tropical forest responses to future climate. 相似文献
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Manly 《Ecology letters》1998,1(2):104-111
Testing for a relationship between the body size of animals and a gradient such as latitude is complicated by the fact that typically there is a single average size for each species, and each species occurs at several sample stations over the gradient. This results in standard tests for statistical significance being invalid. This problem can be overcome by using a randomization test. A more difficult problem, however, is determining whether the relationship between size and latitude is the same for two subfamilies of species. In this paper a general method for relating body size to latitude and subfamily differences is proposed, with the significance of effects determined by randomization. A simulation study suggests that this procedure has good properties. This approach to data analysis has promise both for the particular situation considered and for other related problems in biogeography. 相似文献
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湖泊湿地是地球上缓解全球变暖的巨大碳汇系统。在气候变化背景下,随着温度、降水等格局的改变,其碳汇功能存在高度的响应过程。基于135篇文献已发表的557项观测数据,运用meta分析的方法,分析全球尺度上气候及地理因素的相互作用对湖泊有机碳组分的影响,包括湖泊沉积物有机碳(Sediment Organic Carbon)、湖水中总有机碳(Total Organic Carbon)、湖水溶解有机碳(Dissolved Organic Carbon)和颗粒有机碳(Particulate Organic Carbon)。结果显示：1)在纬度3°49′N—76°24′N和海拔0—4500m范围内,SOC、TOC、POC和DOC的变化范围分别为0.25—15.6 g C/Kg、1.9—25.11 mg C/L、0.026—24 mg C/L、1—115.4 mg C/L;2)地理因素中,海拔与TOC呈显著的负相关(P<0.05),每升高1m, TOC增加0.0077 mg/L;纬度与POC呈显著负相关,与DOC呈显著正相关(P<0.05),每增加1°,POC减少0.136 mg/L,DOC增加1.18 mg/L;3)气候因素中,年均温与SOC和POC呈显著的正相关,与DOC呈显著负相关(P<0.05),每升高1℃,SOC和POC增加0.079 g/kg、0.36 mg/L,DOC下降1.52 mg/L;年均降水量与POC呈显著正相关,与DOC呈显著负相关(P<0.05),每增加100mm, POC增加0.87 mg/L,DOC减少3 mg/L;4)气候和地理因素对SOC、TOC、POC、DOC综合影响的贡献度分别达到16.1%、14%、90%、61.6%;5)最热季度的降水对SOC的影响成正相关,其他季节性气候参数对湖水中TOC和SOC均无显著性影响;最冷季的降水因素是影响POC的主要因素,最潮湿月份、最潮湿季节的降水量和最冷季度的平均温度与POC呈显著正相关关系;最干燥月份、最干旱地区、最热季度和最冷季度的降水量对DOC的影响最显著。 相似文献
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利用内蒙古羊草草原围栏样地连续两年的地上、地下生物量数据和当地同时期的降水、气温资料,分析了退化羊草草原,在恢复过程中植被根冠比动态及与水热因子之间的关系。研究结果表明：（1）羊草草原植被地上、地下生物量季节变化均呈单峰型曲线,峰值出现在8月。（2）羊草草原植被根冠比具有明显的季节变化,生长季初和生长季末根冠比值较大,最低值出现在地上生物量最高的8月中下旬。（3）羊草草原植被月根冠比与上上月月降水量相关关系极显著,与七月平均气温相关关系显著;以根冠比为因变量,上上月月降水量、上月平均气温为自变量可分别建立线性回归方程。该方程可以较好地模拟羊草草原植被生长季内月根冠比的动态变化,这样在草地恢复过程中,可由上月的水热因子来指导下月的草地管理,并为更准确地估算草原生态系统生产力及碳储存动态提供重要参数。 相似文献
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A field study was conducted to examine the relationships between the root-shoot ratio dynamics and the precipitation and temperature of the typical Leymus chinensis steppe recovering from grazing in Inner Mongolia, China. A former piece of pasture land that had been fenced off for 2 years was selected for the study, and aboveground and belowground biomass was collected from the study site along with local precipitation and temperature observations during the study period and was used in the analysis. The results indicated that 1) the seasonal change in both aboveground and belowground biomass in Leymus chinensis steppe demonstrated a pattern with a single peak occurring in August. 2) The root-shoot ratio showed a seasonal variation, with relatively high values at the beginning and the end of the growing season. The minimum ratio occurred in late August when the aboveground bio-mass reached its maximum. 3) The monthly root-shoot ratio was significantly correlated (p < 0.05) with the monthly precipitation two months ago, and with the mean temperature in the previous month. A regression model was built with the root-shoot ratio as the dependent variable, and precipitation and temperature as the independent variables. This regression could be used to model the monthly root-shoot ratio dynamics of Leymus chinensis steppe during the growing season. 相似文献