Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1111/j.1365-2745.2007.01289.x |
The rhythm of savanna patch dynamics | |
Meyer, Katrin M.; Wiegand, Kerstin; Ward, David; Moustakas, Aristides | |
通讯作者 | Meyer, Katrin M. |
来源期刊 | JOURNAL OF ECOLOGY
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ISSN | 0022-0477 |
出版年 | 2007 |
卷号 | 95期号:6页码:1306-1315 |
英文摘要 | 1. Patch dynamics is a new, potentially unifying mechanism for the explanation of tree-grass coexistence in savannas. In this scale-explicit paradigm, savannas consist of patches in which a cyclical succession between woody and grassy dominance proceeds spatially asynchronously. The growing ecological and economic problem of shrub encroachment is a natural transient phase in this cycle. 2. An important step towards understanding patterns at the landscape scale is achieved by investigating mechanisms at a smaller scale. We developed the spatially explicit individual-based simulation model SATCHMO to test the null hypothesis that cyclical succession cannot emerge from a realistic patch scale simulation model of the population dynamics of savanna woody species. 3. We calculated the partial temporal autocorrelation coefficient for 100 simulated time series of shrub cover over 500 years for time lags of up to 200 years to establish the existence and duration of successional cycles. We found a significant positive autocorrelation indicating the existence of cycles with a typical duration of about 33 years. 4. The shrub size frequency distributions over the course of a cycle showed shifts from dominance of small shrub sizes towards larger sizes during the increasing phase of a cycle and the reverse in the declining phase. This supports the three phase explanation as follows: (i) an initial phase when spatially and temporally overlapping favourable conditions lead to mass recruitment of shrubs; (ii) a build-up phase when the shrub cohort grows; and (iii) a break-down phase when increased competition due to crowding and unfavourable conditions lead to the break-down of the shrub cohort. The frequency distribution of shrub age at death over 10 simulations was also in agreement with this explanation. 5. We investigated the relationship between shrub cover, annual precipitation and time-lagged shrub cover to identify the driver of the cyclical successions. More than 90% of the variation in shrub cover was explained by shrub cover of the previous year, precipitation, and their interaction. 6. With the demonstration of precipitation-driven cyclical succession at the patch scale, we show that the mechanistic, temporal component of patch dynamics can be used to explain tree-grass coexistence in semi-arid savannas. |
英文关键词 | Acacia mellifera cyclical succession individual-based simulation model patch scale scale shrub encroachment size-frequency distributions temporal autocorrelation tree-grass coexistence |
类型 | Article |
语种 | 英语 |
国家 | Germany ; South Africa |
收录类别 | SCI-E |
WOS记录号 | WOS:000250265700013 |
WOS关键词 | TREE-GRASS COEXISTENCE ; EAST-AFRICAN SAVANNA ; BUSH ENCROACHMENT ; WOODY VEGETATION ; ARID SAVANNA ; MECHANISMS ; BOTSWANA ; ECOLOGY ; PATTERN ; MODEL |
WOS类目 | Plant Sciences ; Ecology |
WOS研究方向 | Plant Sciences ; Environmental Sciences & Ecology |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/154945 |
作者单位 | (1)Univ Jena, Inst Ecol, D-07743 Jena, Germany;(2)Univ KwaZulu Natal, Sch Biol & Conservat Sci, ZA-3209 Scottsville, South Africa |
推荐引用方式 GB/T 7714 | Meyer, Katrin M.,Wiegand, Kerstin,Ward, David,et al. The rhythm of savanna patch dynamics[J],2007,95(6):1306-1315. |
APA | Meyer, Katrin M.,Wiegand, Kerstin,Ward, David,&Moustakas, Aristides.(2007).The rhythm of savanna patch dynamics.JOURNAL OF ECOLOGY,95(6),1306-1315. |
MLA | Meyer, Katrin M.,et al."The rhythm of savanna patch dynamics".JOURNAL OF ECOLOGY 95.6(2007):1306-1315. |
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