摘要
桦木属(Betula)树种作为北方温带森林的先锋树种,在次生林恢复中起重要作用。在当前的气候变化背景下,桦木属不同种类树干木质部解剖特征对气候变化的响应与适应策略还知之甚少。该研究以黑龙江省穆棱市东北红豆杉国家级自然保护区的3种天然桦木:白桦(B.platyphylla)、黑桦(B.dahurica)和硕桦(B.costata)为研究对象,运用树轮年代学和树轮解剖学方法,比较了3种桦木木质部导管特征,分析了导管特征与季节气候因子关系、时间稳定性及生长对极端气候的抵抗力与恢复力。结果表明:3种桦木导管数量和密度都与轮宽显著正相关。白桦在3个树种中平均轮宽最宽,导管小且多。黑桦和硕桦平均轮宽较小,导管明显大而少,可能使黑桦和硕桦更容易产生栓塞。3种桦木的径向生长主要受水分因素的限制,温度限制作用不明显。3种桦木导管数量与各季节降水量正相关,其中硕桦的正相关关系最强。春季气温上升,促进白桦导管变多,非生长季(11月至次年4月)气温升高使黑桦导管变多而硕桦导管数量变少。随着气候变暖,黑桦导管更趋向于小而多,硕桦导管更倾向于小而少。3种桦木径向生长对生长季干旱和非生长季高温的抵抗力和恢复力趋势在种间大致相同,且对非生长季高温的抵抗力和恢复力均较低。黑桦对非生长季高温的响应在个体间变异较大。该研究发现不同桦木木质部导管应对气候变暖的策略不同,白桦采取较为保守的策略(产生较多且较小导管)应对气候变化;硕桦则采用大导管提高水分运输效率的策略,这可能导致其最先衰退,甚至死亡;黑桦介于白桦和硕桦之间,导管数量和面积适中。
Aims As pioneer tree species in temperate and boreal forests,birch species(Betula spp.)play an important role in the restoration of secondary forests.Under the current climate change,little is known about the anatomical characteristics of the xylem of different birch species in response to climate change and their adaptation strategies.Therefore,we aim to study the relationship between the characteristics of their xylem vessels and climate,to reveal the response and adaptation strategies of Betula spp.to climate change,and to provide theoretical basis for accurately assessing the impact of climate change on different Betula spp.populations.Methods In this paper,three natural birch species(B.platyphylla,B.dahurica and B.costata)from Taxus cuspidata National Nature Reserve in Muling,Heilongjiang,China were selected as the research objects.By means of dendrochronology and tree-ring anatomy,we compared these characteristics of xylem vessels of the three birch species,and analyzed the relationship between the characteristics of xylem vessels and seasonal climatic factors,temporal stability,as well as the resistance and recovery of growth to extreme climate.Important findings(1)The vessel number and vessel density were significantly positively correlated with ring width for all three birch species.The average ring width of B.platyphylla was the widest among the three species,and the vessels were small and numerous.In B.dahurica and B.costata,the average ring width was smaller,and the vessel was significantly larger and less,which made B.dahurica more prone to embolism.(2)The growth of the three species of birch was mainly limited by moisture factors and less limited by temperature.The vessel number of the three birch species was positively correlated with precipitation in each season,and the strongest positive correlation was found in B.costata.The increase of temperature in spring promoted the increase of number of vessels,while the number of birch vessels decreased with the increase of temperature in non-growing seasons.As the climate warmed,B.dahurica tended to have smaller and more vessels,while B.costata tended to have smaller and fewer vessels.(3)The trends of resistance and recovery to drought in the growing season and heat in the non-growing season were similar among the three species,and the resistance and recovery to heat in the non-growing season were lower among the three species.There was great variation among individuals of B.dahurica in response to high temperature in non-growing season.We found that different birch species had different strategies of xylem vessel characteristics to cope with climate warming.B.platyphylla adopted a more conservative strategy(producing more and smaller vessels)to cope with climate change,while B.costata initially adopted a strategy to improve water transport efficiency through large vessels,which may lead to the first decline and even death.B.dahurica’s strategy was between B.platyphylla and B.costata,with moderate number and size of vessels.
作者
白雨鑫
苑丹阳
王兴昌
刘玉龙
王晓春
BAI Yu-Xin;YUAN Dan-Yang;WANG Xing-Chang;LIU Yu-Long;WANG Xiao-Chun(Center for Ecological Research,Key Laboratory of Sustainable Forestry Ecosystem Management-Ministry of Education,Northeast Forestry University,Harbin 150040,China;Heilongjiang Ecology Institute,Harbin 150081,China;and 3Mudanjiang Forest Ecosystem Research Station,Mudanjiang,Heilongjiang 157500,China)
出处
《植物生态学报》
CAS
CSCD
北大核心
2023年第8期1144-1158,共15页
Chinese Journal of Plant Ecology
基金
国家自然科学基金(41877426和42177421)
中央高校基本科研业务费专项资金(2572022AW04)。