Arid Zone Research ›› 2024, Vol. 41 ›› Issue (6): 1079-1088.doi: 10.13866/j.azr.2024.06.16

• Agricultural Ecology • Previous Articles    

Characterization of the freezing injury to Juglans regia at different slope positions in the West Tianshan valley of Xinjiang, China

LIU Huaqing1(), WANG Bo2, JIA Yanyan1, XIE Xinran1, ZHANG Wei1,3()   

  1. 1. College of Biological Science and Technology, Yili Normal University, Yining 835000, Xinjiang, China
    2. College of Resources and Environment, Yili Normal University, Yining 835000, Xinjiang, China
    3. Key Laboratory of Plant Resources Protection and Utilization in Xinjiang Yili Valley, Yining 835000, Xinjiang, China
  • Received:2023-09-26 Revised:2024-01-26 Online:2024-06-15 Published:2024-07-03

Abstract:

Severe freezing injury has a significant impact on the growth and development of walnuts (Juglans regia), even leading to plant death in some cases. This study employed the sample method to examine the freezing injury to J. regia in the Wild Walnut Nature Reserve located in the West Tianshan valley in Xinjiang. The distribution characteristics of freezing injury among J. regia were analyzed, and the influence of tree height, crown width, and slope position on the extent of freezing injury was investigated. The results indicated that (1) the total freezing injury rate of J. regia was 87.1%. Among these, the proportion of plants with grade 2 freezing injury was the largest (43.4%), followed by grade 1 (22.5%), grade 3 (17.5%), and grade 4 (3.7%). (2) the proportion of freezing injury in J. regia plants was the largest in the middle of slope (46.5%), followed by the bottom (35.9%), and the top (4.7%); the proportion of uninjured plants was the maximum at the top of slope (7.4%), followed by the bottom (3.3%), and the middle (2.2%). (3) the proportion of freezing injured plants in the six height classes (H) was most prominent in H1 (43.4%), followed by H4 (19.5%), H6 (17.0%), H5 (15.7%), H3 (4.3%), and H2 (0.1%). (4) the proportion of freezing injured plants in the six crown width classes (CW) was most extensive in CW1 (43.4%), followed by CW4 (22.1%), CW3 (20.3%), CW5 (9.5%), CW2 (2.9%), and CW6 (1.8%). (5) the proportion of freezing injured plants in different H and CW classes at the same slope position differed significantly (P<0.05). Plants with grade 1 and 2 freezing injuries were mainly restricted to the middle and bottom of the slope, and those with grade 3 and 4 injuries to the middle. (6) freezing injury in plants was markedly correlated with diameter at breast height (P<0.05) and extremely negatively correlated with CW (P<0.01). Most J. regia plants in the Reserve suffered from freezing injury, and the proportions of freezing injury grades varied conspicuously among the different slope positions and different H and CW classes. The results of this study provide a scientific reference for the management of the Wild Walnut Nature Reserve and the prevention of freezing injury in J. regia.

Key words: Juglans regia, freezing injury, tree height, crown width, slope position, Xinjiang