{"title":"[Responses of radial growth of <i>Larix principis-rupprechtii</i> at different densities to drought events].","authors":"Zi-Hang Zhang, Heng Wang, Jian-Heng Jia, Hao-Kang Sun, Jia-Xuan Han, Ming-Ming Guo","doi":"10.13287/j.1001-9332.202405.005","DOIUrl":null,"url":null,"abstract":"<p><p>In recent years, a surge in drought occurrences has dramatically impacted tree growth worldwide. We examined the ecological resilience of <i>Larix principis-rupprechtii</i> plantations with varying densities (1950, 2355, and 2595 trees·hm<sup>-2</sup>) at the Saihanba Mechanical Forest Farm, by extracting the increment cores using the standard dendrochronological method to measure individual-tree basal area increments (BAI) as part of our assessment of ecological resilience, including resistance (<i>R</i><sub>t</sub>), recovery (<i>R</i><sub>c</sub>), and resilience (<i>R</i><sub>s</sub>). The results showed that drought events occurred in 2006-2010, 2015, and 2018. The <i>R</i><sub>t</sub> for <i>L. principis-rupprechtii</i> plantations varied from 0.76 to 2.01 across three drought events, indicating generally high resistance, except for the plantation with 2355 trees·hm<sup>-2</sup> during the second dry year (<i>R</i><sub>t</sub>=0.69). The <i>R</i><sub>t</sub> for the plantation with 2595 trees·hm<sup>-2</sup> significantly decreased across all drought events, while no significant change was observed in the plantations with 1950 and 2355 trees·hm<sup>-2</sup>. The <i>R</i><sub>c</sub> showed no differences in response to a single drought event across plantation densities, with a significant upward trend for all the densities with each occurrence of drought event. There was no significant difference in the resilience of different densities of <i>L. principis-rupprechtii</i> to the first drought event, whereas the plantation with 2595 trees·hm<sup>-2</sup> exhibited significantly lower <i>R</i><sub>s</sub> during the second and third drought events compared with 1950 and 2355 trees·hm<sup>-2</sup>, respectively. During the 2015 drought event, plantation with 2595 trees·hm<sup>-2</sup> experienced a significant growth decline (radial growth change rate was -26.5%), while no such decline was observed in the plantations with 1950 and 2355 trees·hm<sup>-2</sup>. Overall, the plantation with 2595 trees·hm<sup>-2</sup> demonstrated the lowest resilience to drought events.</p>","PeriodicalId":35942,"journal":{"name":"应用生态学报","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"应用生态学报","FirstCategoryId":"1087","ListUrlMain":"https://doi.org/10.13287/j.1001-9332.202405.005","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"Environmental Science","Score":null,"Total":0}
引用次数: 0
Abstract
In recent years, a surge in drought occurrences has dramatically impacted tree growth worldwide. We examined the ecological resilience of Larix principis-rupprechtii plantations with varying densities (1950, 2355, and 2595 trees·hm-2) at the Saihanba Mechanical Forest Farm, by extracting the increment cores using the standard dendrochronological method to measure individual-tree basal area increments (BAI) as part of our assessment of ecological resilience, including resistance (Rt), recovery (Rc), and resilience (Rs). The results showed that drought events occurred in 2006-2010, 2015, and 2018. The Rt for L. principis-rupprechtii plantations varied from 0.76 to 2.01 across three drought events, indicating generally high resistance, except for the plantation with 2355 trees·hm-2 during the second dry year (Rt=0.69). The Rt for the plantation with 2595 trees·hm-2 significantly decreased across all drought events, while no significant change was observed in the plantations with 1950 and 2355 trees·hm-2. The Rc showed no differences in response to a single drought event across plantation densities, with a significant upward trend for all the densities with each occurrence of drought event. There was no significant difference in the resilience of different densities of L. principis-rupprechtii to the first drought event, whereas the plantation with 2595 trees·hm-2 exhibited significantly lower Rs during the second and third drought events compared with 1950 and 2355 trees·hm-2, respectively. During the 2015 drought event, plantation with 2595 trees·hm-2 experienced a significant growth decline (radial growth change rate was -26.5%), while no such decline was observed in the plantations with 1950 and 2355 trees·hm-2. Overall, the plantation with 2595 trees·hm-2 demonstrated the lowest resilience to drought events.