基于 FAREAST 模型的青海云杉中-幼龄林生物量 碳沿海拔梯度分布特征

为预测未来青海云杉在不同海拔梯度上的分布范围，基于 FAREAST 模型，对祁连山西部、 中部和东部 3 个站点的青海云衫（Picea crassifolia）中-幼龄林（0～60 a）生物量碳的海拔分布特征进 行模拟。结果表明：（1）在同一站点，青海云杉幼苗幼树生物量碳在中间海拔分布最多，集中在海 拔 2 800～3 100 m 之间，此范围以外，生物量碳随之减少。（2）不同站点比较，青海云杉幼苗幼树平 均生物量碳在祁连山中部最高，达到 27.48 ± 5.51 t·C·hm-2，其次为东部的 24.56 ± 3.50 t·C·hm-2 和 西部的 23.80 ± 2.07 t·C·hm-2。（3）青海云杉幼苗幼树分布的海拔范围约在 2 500～3 400 m 之间，但 不同站点间存在差异。模拟得出，祁连山区青海云杉幼苗幼树生物量碳分布存在最佳海拔区间 2 800～3 100 m，高于或低于该区间时，青海云杉的生长和更新过程将会受到限制。祁连山中部青 海云杉幼苗幼树生物量碳高于东部和西部，表明中部是青海云杉生长和潜在分布的最佳区域，导 致东、西部区域更新较差的原因可能是由于东部受人类活动的影响更加频繁，而西部山区则可能 更易受干旱胁迫的影响。

Simulating the biomass carbon distribution of young-and-middle aged Picea crassifolia forests based on FAREAST model along altitude gradients

Picea crassifolia is a dominant tree species of the forests in northwestern China’s Qilian Mountains, where it plays important roles in carbon cycling, carbon storage, and various ecosystem services such as water retention and sand fixation. However, the forest area of P. crassifolia continues to shrink because of irresponsible usage of forest resources, which is resulting in reduced ecological service function. Thus, it is necessary to restore the P. crassifolia forest area. Because of the loads of important information that can be provided by the distribution of biomass carbon of P. crassifolia seedlings and saplings along altitude gradients, it is crucial to understand the distribution of the region’s youngandmiddle- aged (0- 60 aged) P. crassifolia forests to successfully implement restoration and conservation programs. In this study, an updated forest gap model, FAREAST, is used to simulate the distribution of biomass carbon of youngand middle- aged P. crassifolia forests along altitude gradients in the western (Qifeng set), eastern (Wushaoling set), and central (Tianlaochi set) Qilian Mountains. The FAREAST model is validated for these sets against survey data. The results of the study are as follows. (1) The biomass carbon of P. crassifolia seedlings and saplings is greatest at medium altitude, i.e.,2 800 – 3 100 m a.s.l.; however, biomass carbon decreases beyond this range. (2) The average biomass carbon of P. crassifolia seedlings and saplings reaches 27.48 ± 5.51 t · C · hm^{- 2}in the Tianlaochi set, followed by 24.56 ± 3.50 t · C · hm^{- 2} in the Qifeng set and 23.80 ± 2.07 t · C · hm^{- 2} in the Wshaoling set. (3) The highest altitude for distribution of biomass carbon of P. crassifolia seedlings and saplings across the Qilian Mountains is 3 400 m a.s.l. and the lowest is2,500 m a.s.l.. The biomass carbon of P. crassifolia seedlings and saplings is higher in the central Qilian Mountains than in the eastern and western parts, which suggests that the central part is optimal for regeneration of P. crassifolia. The results from the study show that the FAREAST forest gap model can be used to inform forest management and ecosystem services function in this region.