Vegetation and Seasonality Shifts during the Late Quaternary Deduced from 13C/12C Ratios of Grazers at Equus Cave, South Africa
Vegetation and Seasonality Shifts during the Late Quaternary Deduced from 13C/12C Ratios of Grazers at Equus Cave, South Africa
复制标题
从南非马属洞穴食草动物的 13C/12C 比率推断第四纪晚期的植被和季节性变化
作者：
J. Lee;P. Beaumont
摘要降雨季节对景观中C3和C4草的相对比例有很大影响，因为它们的相对分布基本上受到生长季节温度的限制;凉爽的生长季节有利于C3草，而温暖的生长季节有利于C4草。本文利用南非北开普省马洞的食草动物牙釉质碳酸盐中的13 C/12 C比值来确定晚第四纪植被和降雨的季节性变化。结果表明，在更新世后期，C3和C4草的相对比例的变化，并在全新世C4草占主导地位。数据显示，在此期间，西北角并没有像最近的气候模型所假设的那样落入冬季降雨区。相反，一个更复杂的情况下，至少有两个时期的增强冬季降雨发生在一个以夏季降雨为主的制度。
Abstract Season of rainfall can be a major influence on the relative proportions of C3 and C4 grasses in a landscape, since their relative distribution is essentially constrained by temperatures during the growing season; cool growing seasons favor C3 grasses, whereas warm ones favor C4 grasses. 13C/12C ratios in tooth enamel carbonate of grazers from the site of Equus Cave, northern Cape Province, South Africa, were used to determine vegetation and rainfall seasonality shifts during the late Quaternary. The results show shifts in the relative proportion of C3 and C4 grasses during the latter stages of the Pleistocene, and domination by C4 grasses in the Holocene. The data show that the northwestern Cape did not fall within a winter rainfall zone during this period as has been postulated in recent climate models. Instead, a more complex situation is suggested in which at least two periods of enhanced winter rainfall occurred within a predominantly summer rainfall regime.