Elements of disturbance that affect epiphyte vitality in a temperate rainforest:an experimental approach

作     者：Nalini M.Nadkarni Kevin D.Kohl 

作者机构：Department of BiologyUniversity of Utah257 South 1400 EastSalt Lake CityUT 84112USA Department of Biological SciencesUniversity of Pittsburgh403B Clapp Hall4249 Fifth AvenuePittsburghPA 115260USA 

出 版 物：《Journal of Plant Ecology》 (植物生态学报（英文版）)

年 卷 期：2019年第12卷第2期

页      面：306-313页

核心收录：

学科分类：0907[农学-林学] 08[工学] 0829[工学-林业工程] 09[农学] 

基　　金：National Science Foundation(EHR 15-14494 and DEB 11-41833 to N.M.N.and DBI 1400456 to K.D.K.) 

主　　题：disturbance epiphytes forest canopy forest dynamics moss Olympic rainforest 

摘      要：Aims Epiphytes are an abundant and diverse component of many wet temperate forests and have significant roles in ecosystem *** is known about the processes and rates of their death and decomposition when they fall from the canopy,which limits our understanding of their role in forest carbon sequestration and nutri-ent *** the temperate rainforest of the Quinault River Valley,Washington State,our aim was to test hypotheses regarding four elements of disturbance that might contribute to their *** We established set of experiments in which we placed samples of canopy epiphytes and their branch segments:(i)in the canopy versus forest floor microenvironment(stratum);(ii)attached to live versus dead branch substrates;(iii)subjected to physical disruption and‘jarring’;and(iv)in direct versus indirect con-tact with the forest *** the 2-year study,we assigned a non-destructive‘vitality index’(based on color and appar-ent mortality and dryness)to each sample every 2-3 months to compare effects of the experimental treatments and analyzed with a statistical model and post hoc pairwise comparisons of *** Findings The canopy versus ground stratum and live/dead branch status sig-nificantly affected epiphyte *** of physical disruption and ground contact were not *** were seasonal effects(low vitality during the sampling times in the summer,revitalization upon sampling times in the winter)for all treatments except samples in contact with the *** implication of these results relates to effects of climate change,which is predicted to shift to hotter,drier summers and wetter *** change may affect forest dynamics and nutrient cycling in unpredictable *** also point to future experiments to understand biotic and abiotic effects on epiphyte disturbance and dynamics.