新疆科克苏湿地植被生物量时空分布特征及与水文连通的关系

区域植被生物量及其与水文连通之间的定量关系对于湿地保护和管理具有重要意义。基于多期Landsat-8遥感影像和野外实地调查数据,提取了新疆科克苏湿地生长季不同月份的湿地水体斑块,反演并分析了湿地植被地上生物量及时空分布特征,量化了水文连通与科克苏湿地植被地上生物量和植被碳库的关系。结果表明: 6月新疆科克苏湿地水体斑块面积最大,占保护区面积的63.12%,之后湿地水体斑块面积逐渐减少,8月水体斑块面积仅占保护区面积的6.27%,水体斑块分布具有明显的季节性特征。科克苏湿地植被生物量呈现聚集分布的空间分布模式,额尔齐斯河及克兰河河道两侧以及支流两侧湿地为高生物量区域,北部阿热勒齐及阔克苏村和东南部萨尔胡松乡为低生物量区域。7月地上生物量达到生长季最高值,该时段科克苏湿地的植被总生物量为1.09×10⁹ kg,最大总生物量为4832 g/m²,地上生物量较高区域分布在西部的阿克铁热克村及东部的巴勒喀木斯村。水文连通与植被地上生物量及植被碳库呈现抛物线关系,水文连通度为0.6左右时,植被地上生物量及植被总碳库最大,植被总碳库达到4.5×10¹¹ kg C。研究揭示了科克苏湿地植被生物量的时空分布特征,建立了科克苏湿地水文连通度与植被地上生物量及植被碳库的量化关系,明确了适宜的水文连通度对植被生物量积累存在促进作用,可为湿地水文连通调控和植被碳储存功能提升提供有效参考。

Spatiotemporal distribution characteristics of vegetation biomass and its relationship with hydrological connectivity in Kekesu Wetland, Xinjiang

The relationship between vegetation biomass and hydrological connectivity is crucial for the preservation and effective management of wetland ecosystem. Our study combined the use of Landsat-8 satellite imagery with the field measured data in Kekesu Wetland, Xinjiang, we not only extracted the wetland water patches of different months during the growing seasons but also estimated aboveground biomass of the wetland. We further investigated the spatial and temporal distribution characteristics of these vital ecological parameters. Additionally, we quantified the relationship between hydrological connectivity and aboveground biomass, as well as plant carbon pool. The results showed that in June, the area covered by water patches in Kekesu Wetland reached its maximum, accounting for 63.12% of the total reserve. However, as the growing season progressed, particularly in August, the extent of water patches diminished significantly, accounting for just 6.27% of the total area. This noticeable seasonal variation underscored the dynamic nature of water patch distribution within the wetland, emphasizing its sensitivity to changing environmental conditions. Exploring the spatial distribution of vegetation biomass in more detail, we observed an aggregated spatial distribution pattern. High biomass concentrations were particularly prominent on both sides of the Irtysh River, the Kran River, and their intricate network of tributaries. In stark contrast, regions such as Azelqi and Kuokesu Villages in the northern sections, as well as Salhuson Township in the southeastern corner, exhibited considerably lower biomass levels. In July, the aboveground biomass reached its peak value during the growing season, with the total vegetation biomass in Kokesu Wetland reaching 1.09×10⁹ kg, and the maximum total biomass measuring 4832 g/m². The areas with higher above-ground biomass are distributed in Aktyrek Village in the west and Balkamus Village in the east. Moreover, we found a nonlinear association between hydrological connectivity and the ecological parameters of interest. The hydrological connectivity showed parabolic relationships with both aboveground biomass and plant carbon pool. The plant carbon pool was the highest when hydrological connectivity was approximately 0.6. The total plant carbon pool reached 4.5×10¹¹ kg C. Our study reveals the spatiotemporal distribution characteristics of vegetation biomass in Kekesu Wetland, establishes a quantitative relationship between hydrological connectivity and aboveground vegetation biomass, as well as the plant carbon pool. Furthermore, we clarify the impact of appropriate hydrological connectivity on vegetation biomass accumulation, demonstrating its positive influence. This research can serve as a valuable reference for the management of wetland hydrological connectivity and the enhancement of vegetation carbon storage functionality.