鄱阳湖区沙化土地属于南方荒漠化的典型类型,其生态治理与恢复对区域生态文明建设具有重要意义.2009—2016年在鄱阳湖区都昌县沙化典型区建立110 hm2沙化土地恢复试验区,通过监测不同沙化区的湿地松(Pinus elliottii)的树高、胸径、冠幅等指标,分析沙地生态恢复试验区内不同沙化程度(轻度、中度、重度)人工栽植的湿地松的恢复状况,选择最佳生物量参考模型估算不同沙化区湿地松地上生物量及其在不同器官中的分配比重.结果表明:(1)轻度沙化区湿地松生长速率较快,2016年9月树高和胸径平均值分别为457 cm和8.61 cm,其树高平均增长达58 cm·a-1;中度、重度沙化区树高分别为303 cm、289 cm,胸径为5.95 cm、6.93 cm,树高平均增长分别为38 cm·a-1和36 cm·a-1;(2)2016年9月,轻度、中度、重度沙化区湿地松冠幅比移栽时(10.63 cm)分别增加了22倍、18倍、17倍;(3)湿地松树干生物量占地上总生物量的比重不断增加,枝生物量比重不断减少,叶生物量比重基本保持稳定,轻度沙化区地上生物量(10241.55 g)远大于中度(4333.56 g)和重度沙化区(6173.16 g);(4)鄱阳湖土地沙化区土壤养分含量低,湿地松的生长主要受气温和降水量两个环境因子的共同影响,气温对湿地松生长的影响大于降水量.湿地松在鄱阳湖土地沙化区干旱贫瘠地带也能旺盛生长.本研究结果可为亚热带地区沙化土地的生态恢复和资源利用等方面提供依据和参考.
The desertification land of the Poyang Lake area belongs to the typical type of south desertification, and its ecological management and restoration have great significance to the construction of regional ecological civilization. We established the ecological restoration experimental area with 110 hm2 of desertification land at the classic desertification area of Douchang county around the Poyang Lake from 2009 to 2016, based on the monitoring of tree height, DBH and crown width of P. elliottii in different desertification areas, analysed the restoration of P. elliottii being studied in the sandy land ecological restoration experimental area with different degrees of desertification (mild, moderate and severe) situation, and choose the best biomass as reference model to estimate the aboveground biomass of P. elliottii and in different desertification and their distribution in different organs. The result showed: (1) The growth rate of P. elliottii is faster in mild desertification area. In September 2016, the height and the average of DBH is 457 cm and 8.61 cm respectively, and the average growth of height reached 58 cm·a-1. The height is 303 cm and 289 cm, DBH is 5.95 cm and 6.93 cm, and the average height of tree height is 38 cm·a-1 and 36 cm·a-1 in moderate and severe desertification area. (2) In September 2016, the crown of P. elliottii is more than transplanting in mild, moderate and severe desertification area respectively increase by 22 times, 18 times and 17 times. (3) The biomass of P. elliottii trunk proportion in the total biomass of aboveground increasing, the branch biomass proportion is reducing, and the leaf biomass proportion remain stable. The mild desertification area individual aboveground biomass (10241.55 g) is much larger than moderate (4333.56 g) and severe desertification area (6173.16 g). (4) The soil nutrient content in the desertification area of Poyang Lake is low, and the growth of P. elliottii is mainly under the mutual influence of two environmental factors (temperature and precipitation). The correlation between the temperature is larger than the correlation of precipitation and pine growth. The results of this study can provide the basis and reference for the ecological restoration and resource utilization of the desertified land in the subtropical region, because of it can flourish in the arid and barren areas of Poyang Lake.