Monitoring of forage conditions with MODIS imagery in the Xilingol steppe, Inner Mongolia
Monitoring of forage conditions with MODIS imagery in the Xilingol steppe, Inner Mongolia
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DOI：
10.1080/01431160512331326783
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发表时间：
2005-04-01
影响因子：
3.4
通讯作者：
Wang, S
中科院分区：
文献类型：
--
作者：
Kawamura, K;Akiyama, T;Wang, S
为了确定Terra/MODIS图像在半干旱区监测饲料条件短期物候变化的潜在适用性，进行了一项研究。研究地点包括内蒙古中部锡林郭勒草原的4个草甸草原和6个典型草原。在4月初至10月下旬，利用500 m像元的增强植被指数（Enhanced Vegetation Index， EVI）估算了活生生物量、枯死生物量、总生物量、粗蛋白质（CP）浓度和枯死生物量。应用回归模型，EVI占活生物量变化量的80%，占死生物量变化量的42%，占总生物量变化量的77%，占CP浓度变化量的11%，占直立CP变化量的74%，MODIS/EVI在估算牧草量时优于AVHRR/NDVI。利用这些结果，可以描述4个不同放牧强度立地的活生物量和立地CP的季节变化。总体而言，放牧强度的增加倾向于降低活生物量和林分CP。从Terra图像中获得的EVI值可以有效地预测以活生物量和林分CP测量的牧草状况，MODIS/EVI值可以为牧场管理者提供适宜的刈割时间和营养价值信息。
A study was conducted to determine the potential suitability of Terra/MODIS imagery for monitoring short-term phenological changes in forage conditions in a semi-arid region. The study sites included four meadow steppes and six typical steppes in the Xilingol steppe in central Inner Mongolia, China. The live biomass, dead standing biomass, total biomass, crude protein (CP) concentration and standing CP were estimated from early April to late October using the Enhanced Vegetation Index (EVI) values from Terra imagery (500 m pixels). Applying regression models, the EVI accounted for 80% of the variation in live biomass, 42% of the dead biomass, 77% of the total biomass, 11% of the CP concentration and 74% of the standing CP. MODIS/EVI is superior to AVHRR/NDVI when estimating forage quantity. Applying these results, the seasonal changes in live biomass and the standing CP could be described in the selected four sites with different degrees of grazing intensity. Generally, the increase in grazing intensity tended to decrease live biomass and standing CP. It was suggested that the EVI obtained from Terra imagery was an available predictor of the forage condition as measured by live biomass and standing CP. The MODIS/EVI values could provide information on the suitable timing of cutting for hay-making and nutritive value to range managers.