关键词: 新疆野果林, 野杏, 非空间结构, 空间结构, 生活力, 健康评价

Abstract: We explored the population structure and survival status of Armeniaca vulgaris, and evaluated the health status and renewal ability of A. vulgaris, in order to provide a theoretical basis for its protection and restoration. A total of 22 plots were set up in four A. vulgaris populations in Xinghuagou (Tuergen Town, Xinyuan County), Yilegedaigou (Tastobe Town, Gongliu County), Daxigou (Daxigou Town, Huocheng County) and Mohegou (Kuerdening Town, Gongliu County) in Xinjiang. We investigated the non-spatial structure (species composition, DBH (DBH≥5 cm), tree height, crown width, canopy density, tree density) and spatial structure (angle scale, mixing degree, size ratio) of each A. vulgaris population. The health status of A. vulgaris was evaluated based on the population structure. The proportion of A. vulgaris in four populations of Xinghuagou, Mohegou, Yilegedaigou and Daxigou was 100%, 73.91%, 97.70% and 36.17%, respectively. The stand density of each population was 565, 322, 435, 575 plants·hm^-2, and the canopy density was 0.92, 0.55, 0.82, 0.78, respectively. The stand density was large and the canopy density was high. The average tree height of four populations was 6.75, 6.48, 6.47, 6.70 m, and the average crown width was 6.00, 5.26, 5.01, 6.20 m, respectively. There was no significant difference in tree height among the four populations, and crown width was large. There was cross-overlapping between tree crowns, with large extent of overlap. The age-class structure of A. vulgaris was basically spindle-shaped, and the overall structure wasunstable. It was mainly composed of 83.60% of mature, middle-aged, and old individuals, while it seriously lacked young individuals (accounting for 10.16%). The average size ratios of Xinghuagou, Mohegou and Yilegedaigou populations were 0.46, 0.45 and 0.49, respectively, with a middle state of DBH growth. The average size ratio of Daxigou population was 0.63, with an inferior state of DBH growth. The mean mingling degree ofA. vulgaris in four populations was 0, 0.05, 0.20 and 0.49, respectively, suggesting that A. vulgaris can survive in pure population and that it can also survive with other wild fruit tree species. The average angular scales of these four populations were 0.39, 0.37, 0.33 and 0.40, respectively, indicating a uniform horizontal distribution. The weighted composite index of Xinghuagou, Mohegou, Yilegedaigou and Daxigou populations was 0.48, 0.45, 0.30 and 0.52, and the weighted sum index was 0.37, 0.48, 0.36 and 0.53,respectively. The health status of A. vulgaris populations in Daxigou and Mohegou was at moderate level. The health grade of Xinghuagou population was moderate by weighted comprehensive index, and was poor by weighted sum index, being moderate to lower by the comprehensive evaluation. The health grade of A. vulgaris population in Yilegedaigou was poor. Based on the structure characteristics and viability of A. vulgaris populations, the current health status of A. vulgaris populations in Xinjiang was at moderate to lower level. The A. vulgaris populations should be urgently protected and restored. This study evaluated the health status A. vulgaris populations from the appearance traits, which can lay a foundation for further study of the survival of A. vulgaris.

Key words: Xinjiang wild fruit forest, Armeniaca vulgaris Lam., non-spatial structure, spatial structure, vitality, health assessment.