Convergence among global biogeographical realms in the physiological niche of evergreen and deciduous vegetation
Convergence among global biogeographical realms in the physiological niche of evergreen and deciduous vegetation
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DOI：
10.1111/geb.12447
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发表时间：
2016-06-01
影响因子：
6.4
通讯作者：
Higgins, Steven I.
中科院分区：
文献类型：
--
作者：
Buitenwerf, Robert;Higgins, Steven I.
目的 叶子部署的季节时间和持续时间对地球-大气相互作用和生物过程具有重大影响。虽然全球变化对叶子展开时间（叶子物候）影响的证据正在积累，但对决定叶子展开持续时间（叶子习性）及其地理分布的机制的了解仍然不完整。叶子习性的理论模型假设选择性环境会导致收敛到最佳叶子习性。在这里，我们研究了不同叶习性的生理生态位的趋同。位置南美洲、非洲、印度太平洋和澳大利亚生物地理领域。方法我们使用来自先进甚高分辨率辐射计（AVHRR）的1981-2012年归一化差异植被指数（NDVI）数据的1981-2012时间序列描绘了三种现象的分布：高叶面积常绿植被、低叶面积常绿植被和落叶植被。对于四个生物地理领域中的每个现象组，我们使用基于过程的植物生长模型量化了生理生态位。每个领域中每个现象的衍生生理生态位维度被用来预测其在其他非本地领域的潜在分布。叶子习性的收敛性被量化为来自所有领域的预测之间的一致性水平。结果本地领域中观察到的现象与预测的现象之间的总体一致性很高（80％），表明该模型充分描述了现象的生理生态位。从每个现象组到非本地领域的预测在 89% 的研究区域中是一致的，这意味着现象组的生理生态位存在广泛的趋同。对于其余 11% 的研究区域，所有领域的预测并不重合，这意味着预测的表型类型是不确定的。 主要结论 不同生物地理领域中同一表型的模拟生理生态位很大程度上重叠。这意味着进化趋同在叶习性的生物地理学中起着主导作用。总的来说，我们的分析表明，全球变化对叶习性地理分布的影响可以通过相对简单的生理模型来预测。 11% 研究区域不收敛的潜在解释包括历史偶然事件和替代稳定状态。
Aim The seasonal timing and duration of leaf deployment has major implications for earth-atmosphere interactions and biotic processes. While evidence for impacts of global change on the timing of leaf deployment (leaf phenology) is accumulating, knowledge of the mechanisms that determine the duration of leaf deployment (leaf habit) and its geographical distribution remains incomplete. Theoretical models of leaf habit assume that a selective environment leads to convergence to an optimal leaf habit. Here we examine convergence in the physiological niche of different leaf habits.Location South American, African, Indo-Pacific and Australian biogeographical realms.Methods We delineated the distribution of three phenomes: high leaf area evergreen vegetation, low leaf area evergreen vegetation and deciduous vegetation, using a 1981-2012 time series of normalized difference vegetation index (NDVI) data from the advanced very high resolution radiometer (AVHRR). For each phenome in each of the four biogeographical realms we quantified the physiological niche using a process-based model of plant growth. The derived physiological niche dimensions of each phenome in each realm were used to project its potential distribution into other, non-native, realms. Convergence in leaf habit was quantified as the level of consistency among the projections from all realms.Results The overall agreement between observed and predicted phenomes in the native realm was high (80%), suggesting that the model adequately describes the physiological niches of phenomes. Projections from each phenome into non-native realms coincided in 89% of the study area, implying widespread convergence of the physiological niches of phenomes. For the remaining 11% of the study area projections of all realms did not coincide, implying that the predicted phenome type is uncertain.Main conclusions Modelled physiological niches of the same phenome in different biogeographical realms largely overlap. This implies a dominant role for evolutionary convergence in the biogeography of leaf habit. Overall, our analysis therefore suggests that the impact of global change on the geographical distribution of leaf habit can be predicted by relatively simple physiological models. Potential explanations for non-convergence on 11% of the study area include historical contingencies and alternative stable states.