Integrating potential distribution of dominant vegetation and land use into ecological restoration in the Yellow River Basin, China

Due to the influence of human activities such as cultivation and urban construction, the ecosystem of the Yellow River Basin (YRB) is subjected to increased vulnerability and even potential risk of destruction. Ecological restoration has led to an increase in vegetation, but excessive afforestation conversely results in low survival rate of trees, water shortages, and biodiversity loss. It is of great significance for achieving sustainable development of forests to reasonable revegetation in the region. At present, the potential distribution pattern of dominant species and their mixed forms in the basin has not been effectively studied. This study simulated the potential distribution of dominant vegetation in the YRB based on Maximum Entropy (MaxEnt) and Genetic Algorithm for Rule-Set Prediction (GARP) and explored the impact of human interference on it by employing land use as the environmental filter to distinguish the regions of human activities. We further predicted the potential distribution of typically mixed forests and discussed their human interference. The main results are as follows: (1) Except for Caragana korshinskii, all models had good above performance (0.7 < the mean AUC < 1). Except for Caragana korshinskii, the area under the curve (AUC) for 90% of the models indicated that MaxEnt performed better than GARP, and MaxEnt easily lead to over-fitting while GARP predicted a wider range. (2) Except for Nitraria tangutorum, the dominant types of vegetation such as Pinus tabulaeformis, Platycladus orientalis, and Hippophae rhamnoides mainly distributed in southern Gansu, Shaanxi, and south-central Shanxi. Among them, the largest suitable area of Artemisia gmelinii and Stipa bungeana (High suitable area) were approximately 56.7×104 km2 (38.8%) and 54.7×104 km2 (28.5%) with the area occupied by large-scale cultivation being 17.5×104 km2 (39.4%) and 18.9×104 km2 (48%), respectively, which indicated human activities caused great damage to the core growth regions of these vegetation. (3) Mean temperature of coldest quarter or month mainly constrained the growth of most vegetation in the YRB in terms of temperature, while precipitation of wettest/driest month is one of the dominant factors. However, some vegetation responded differently to other meteorological factors due to niche differences. (4) Most of the mixed forests were distributed in southern Gansu, Shaanxi, and Shanxi provinces; its middle and high suitable areas were mainly concentrated in Shaanxi and southern and central Shanxi, where the cultivated land had occupied most of them. Therefore, the results showed that the restoration of herbaceous vegetation such as Artemisia gmelinii and Stipa bungeana has a high potential and it is appropriate that the measures for afforestation should be concentrated in the areas like the lower reaches of the Weihe, Jinghe, and Beiluo rivers and Luliang Mountain, where the cultivated land overlaps with the high suitable areas of the corresponding vegetation and the mixed forests with less water consumption and wide distribution, such as Caragana korshinskii-Hippophae rhamnoides, Pinus tabulaeformis-Quercus liaotungensis, and Ostryopsis davidiana-Stipa bungeana- Hippophae rhamnoides. The results of this study can provide effective guidance for mixed forest plantations and vegetation conservation in the YRB.