冀西北水源涵养区不同类型人工针叶林生态功能差异性评估

人工造林被认为是增加碳汇、保持水土和提高水质最有效的方法之一,造林林种的不同将产生不同的生态效应。通过调研土壤、气象及生态化学计量参数等对CENTURY模型进行本地化,模拟冀西北水源涵养区主要针叶造林树种[落叶松(dahurian larch)、油松(pinus tabulaeformis)、侧柏(oriental arborvitae)和樟子松(Pinus sylvestris var. mongolical)]的生态效应,并结合文献数据评价模型拟合精度。模型模拟结果显示:与幼龄林相比,落叶松、油松、侧柏和樟子松中龄林的土壤C、N、P总储量分别增加了3.37%、3.98%、2.84%和1.82%,土壤含水量增加了151.25%、73.62%、41.83%和94.98%。不同林种两个林龄平均蒸发量比较显示,落叶松(338.85 mm)<油松(399.86 mm)<侧柏(400.52 mm)<樟子松(401.82 mm)。落叶松可以作为水源涵养区造林的优选树种。樟子松和落叶松具有较强的N、P吸收能力,建议在农业污染的下游区域推广樟子松和落叶松的种植。

Difference assessment on ecological functions of artificial coniferous forests in water conservation area of Northwestern Hebei

Artificial afforestation is considered to be one of the most effective ecological methods to increase carbon sequestration, conserve water and soil, and improve water quality. This study focuses on the main coniferous afforestation tree species (Dahurian larch, Pinus tabulaeformis, Oriental arborvitae and Pinus sylvestris var. mongolical) of Zhangjiakou, based on long-term soil and meteorological data, as well as physiological parameters data of afforestation tree species obtained from literature data with similar conditions, and localized the CENTURY model. The validation data derived from literature investigation is used to evaluate the fitting precision of CENTURY model. The results showed that the CENTURY model had a good simulation on SOC, biomass and soil water content, which could be used for the ecological function assessment of artificial coniferous forest in Zhangjiakou. Compared with young plantation, the results of CENTURY model simulation show that the total reserves of soil C, N and P in half-mature forest of Dahurian larches, Pinus tabulaeformis, Oriental arborvitae and Pinus sylvestris var. mongolical increased by 3.37%, 3.98%, 2.84% and 1.82%, respectively, and the soil water contents increased by 151.25%, 73.62%, 41.83% and 94.98%, respectively. The average evapotranspiration of two ages of Dahurian larches (338.85 mm) < Pinus tabulaeformis (399.86 mm) < Oriental arborvitae (400.52 mm) < Pinus sylvestris var. mongolical (401.82 mm) were compared between different forest species. Dahurian larches can be used as the best afforestation tree species in water conservation area. Pinus sylvestris var. mongolical and Dahurian larches were suggested to be promoted in the downstream areas polluted by agricultural production. This study can provide a reference for ecological engineering construction aimed at different ecological function goals.