Variation in stem mortality rates determines patterns of above-ground biomass in Amazonian forests: implications for dynamic global vegetation models.
Variation in stem mortality rates determines patterns of above-ground biomass in Amazonian forests: implications for dynamic global vegetation models.
复制标题
DOI：
10.1111/gcb.13315
复制
发表时间：
2016-12
影响因子：
11.6
通讯作者：
Baker TR
中科院分区：
文献类型：
--
作者：
Johnson MO;Galbraith D;Gloor M;De Deurwaerder H;Guimberteau M;Rammig A;Thonicke K;Verbeeck H;von Randow C;Monteagudo A;Phillips OL;Brienen RJ;Feldpausch TR;Lopez Gonzalez G;Fauset S;Quesada CA;Christoffersen B;Ciais P;Sampaio G;Kruijt B;Meir P;Moorcroft P;Zhang K;Alvarez-Davila E;Alves de Oliveira A;Amaral I;Andrade A;Aragao LE;Araujo-Murakami A;Arets EJ;Arroyo L;Aymard GA;Baraloto C;Barroso J;Bonal D;Boot R;Camargo J;Chave J;Cogollo A;Cornejo Valverde F;Lola da Costa AC;Di Fiore A;Ferreira L;Higuchi N;Honorio EN;Killeen TJ;Laurance SG;Laurance WF;Licona J;Lovejoy T;Malhi Y;Marimon B;Marimon BH Junior;Matos DC;Mendoza C;Neill DA;Pardo G;Peña-Claros M;Pitman NC;Poorter L;Prieto A;Ramirez-Angulo H;Roopsind A;Rudas A;Salomao RP;Silveira M;Stropp J;Ter Steege H;Terborgh J;Thomas R;Toledo M;Torres-Lezama A;van der Heijden GM;Vasquez R;Guimarães Vieira IC;Vilanova E;Vos VA;Baker TR
了解决定亚马逊森林地上生物量（AGB）的过程对于预测这些生态系统对环境变化的敏感性以及设计和评估动态全球植被模型（DGVM）非常重要。AGB是由来自木质生产力[木质净初级生产力（NPP）]的输入和通过树木死亡损失碳的速率决定的。在这里，我们测试了树木死亡率的两个直接指标（木质生物量损失的绝对速率和树干死亡率）和/或木质NPP是否控制了亚马逊流域完整森林中167个地块中AGB的变化。然后，我们比较这些关系和观察到的AGB和木本NPP的变化与四个DGVM的预测。观测结果表明，干死亡率，而不是绝对率的木本生物量损失，是最重要的预测AGB，这是一致的林分大小结构的重要性，确定空间变异AGB。干死亡率和AGB之间的关系在亚马逊河流域的不同地区，表明木材密度和高度/直径关系的变化也影响AGB。与以前的研究结果相反，我们发现，木本NPP是不相关的干死亡率和AGB弱正相关。在四个模型中，流域范围内的平均AGB与观测值的平均值相似。然而，该模型一致高估了木本NPP和不良代表的空间格局的AGB和木本NPP估计使用地块数据。与观测结果形成鲜明对比的是，DGVM通常表现出木本NPP和AGB之间的强正相关关系。解决这些差异将需要将森林规模结构，干死亡率和DGVM功能组成的变化机制模型。
Understanding the processes that determine above‐ground biomass (AGB) in Amazonian forests is important for predicting the sensitivity of these ecosystems to environmental change and for designing and evaluating dynamic global vegetation models (DGVMs). AGB is determined by inputs from woody productivity [woody net primary productivity (NPP)] and the rate at which carbon is lost through tree mortality. Here, we test whether two direct metrics of tree mortality (the absolute rate of woody biomass loss and the rate of stem mortality) and/or woody NPP, control variation in AGB among 167 plots in intact forest across Amazonia. We then compare these relationships and the observed variation in AGB and woody NPP with the predictions of four DGVMs. The observations show that stem mortality rates, rather than absolute rates of woody biomass loss, are the most important predictor of AGB, which is consistent with the importance of stand size structure for determining spatial variation in AGB. The relationship between stem mortality rates and AGB varies among different regions of Amazonia, indicating that variation in wood density and height/diameter relationships also influences AGB. In contrast to previous findings, we find that woody NPP is not correlated with stem mortality rates and is weakly positively correlated with AGB. Across the four models, basin‐wide average AGB is similar to the mean of the observations. However, the models consistently overestimate woody NPP and poorly represent the spatial patterns of both AGB and woody NPP estimated using plot data. In marked contrast to the observations, DGVMs typically show strong positive relationships between woody NPP and AGB. Resolving these differences will require incorporating forest size structure, mechanistic models of stem mortality and variation in functional composition in DGVMs.
登录
查看更多内容
影响因子：
9.4
作者：
Fisher, Rosie;McDowell, Nate;Woodward, F. Ian
通讯作者：
Woodward, F. Ian
影响因子：
5.5
作者：
Banin, Lindsay;Lewis, Simon L.;Phillips, Oliver L.
通讯作者：
Phillips, Oliver L.
影响因子：
1.5
作者：
Galbraith, David;Malhi, Yadvinder;Lloyd, Jon
通讯作者：
Lloyd, Jon
影响因子：
4.9
作者：
Delbart, N.;Ciais, P.;Le Toan, T.
通讯作者：
Le Toan, T.
影响因子：
4.9
作者：
Feldpausch, T. R.;Banin, L.;Lloyd, J.
通讯作者：
Lloyd, J.