Responses of radial growth of Larix principis-rupprechtii at different densities to drought events
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(R,),recovery(Rc),and resilience(Rs).The results showed that drought events occurred in 2006-2010,2015,and 2018.The R,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 differ-ence in the resilience of different densities of L.principis-rupprechtii to the first drought event,whereas the planta-tion 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 demon-strated the lowest resilience to drought events.
万方数据
维普
