Spatiotemporal variation in the microclimatic edge effect between wetland and farmland
| 第一作者： |
廖晓玉 |
| 英文第一作者： |
Liao, X. Y. |
| 联系作者： |
刘兆礼 |
| 英文联系作者： |
Liu, Z. L. |
| 发表年度： |
2013 |
| 卷： |
118 |
| 摘要： |
The creation of wetland edges associated with anthropogenic fragmentation is common in wetland landscapes and brings about a unique microclimatic change that affects adjacent farmland. However, microclimatic edge effects within this kind of landscape are not well quantified. Thus, using a study site located in the northeastern Sanjiang National Nature Reserve, China, we investigated the spatiotemporal variations in the microclimatic variables of the surface layer across the wetland-farmland edge. Air temperature and relative humidity data were collected continuously along a horizontal transect at four different heights over different periods, and the relative humidity was converted to specific humidity. Sigmoid models were used to fit the horizontal gradients of microclimatic edge effects. Then, based on the parameters in the fitted models, the characteristics of the edge effects were quantified with two indices, the magnitude of edge effect (MEE) and the spatial range of edge effect (REE). Under a light wind condition, the microclimatic features across the edge generally presented sigmoid ecological gradients in the horizontal direction, with unique spatial and temporal patterns: (1) In a normal year, wetland patches cooled and moistened the adjacent farmlands during the daytime and had a warming-moistening effect during the nighttime. (2) Vertically, the absolute MEE value of the microclimatic variables decreased, but the REE increased with increasing height. (3) The MEE and REE for air temperature and specific humidity varied with the time of day, both shifting at dawn and dusk when the gradients were absent. (4) At the interannual scale, when compared to the farmland, the wetland was cooler at night in a dry year but warmer in a normal year. The detection of spatiotemporal microclimatic patterns in the wetland-farmland edge zone may enable further understanding of how wetland degradation affects adjacent farmland ecology under human disturbance and promote better management and restoration of fragmented wetlands. |
| 刊物名称： |
Journal of Geophysical Research-Atmospheres |
| 参与作者： |
刘兆礼，王毅勇，金继明 |
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