李树桥小流域湿地松生长规律及Verhaulst 预测模型的建立与讨论

湿地松是优良水土保持树种，为客观反映湿地松的水土保持效益与经济效益。观测统计李树桥小流域湿地松幼树连年逐季定株观测的生长过程信息，构建湿地松幼树的树高、地围径和冠幅直径生长过程Verhaulst预测模型并进行预测分析。结论为：湿地松多年生长过程曲线为阶梯形，具有一定的周期性，如不加强抚育管理，仅采取封禁措施，很有可能会成为“小老树”；Verhaulst模型适合于建立数据系列较短的湿地松生长过程模型，数据要求低、精度较高，宜在江南红壤丘陵区推广。

Establishment and discussion of Pinus elliottii growth law and verhalst prediction model in Lishuqiao small watershed

Pinus elliottii is one of the excellent tree species for soil and water conservation. In order to objectively reflect the soil and water conservation and economic benefits of Pinus elliottii, the growth process information of 7 Young Pinus elliottii trees in Lishuqiao small watershed was observed and counted year by year, and the verhalst prediction model for the growth process of tree height, ground girth diameter and crown diameter of Young Pinus elliottii trees was constructed and analyzed. The conclusions are as follows: 1. The growth process curve of Pinus elliottii for years is step-shaped and periodic. If we do not strengthen tending management and only take closure measures, it is likely to become "small old trees"; 2. Verhalst model is suitable for establishing the growth process model of Pinus elliottii with short data series. It has the features of low demand for data and high accuracy, and can be popularized in the red soil hilly areas of the south of the Yangtze River.