Forest Type and Tree Characteristics Determine the Vertical Distribution of Epiphytic Lichen Biomass in Subtropical Forests

Abstract

Epiphytic lichens are an important component in subtropical forests and contribute greatly to forest biodiversity and biomass. However, information on epiphytic lichens still remains scarce in forest conservation owing to the difficulty of accessing all canopy layers for direct observation. Here, epiphytic lichens were quantified on 73 whole trees in five forest types in Southwest China to clarify the vertical stratification of their biomass in subtropical forests. Lichen biomass was significantly influenced by forest type and host attributes, varying from 187.11 to 8.55 g•tree −1 among forest types and from 289.81 to <0.01 g•tree −1 among tree species. The vertical stratification of lichen biomass was also determined by forest type, which peaked at the top in primary Lithocarpus forest and middle-aged oak secondary forest and in the middle upper heights in other forests. Overall, the proportion of lichen biomass accounted for 73.17-100.00% of total lichen biomass on branches and 0.00-26.83% on trunks in five forests, and 64.53-100.00% and 0.00-35.47% on eight host species. Seven functional groups showed marked and various responses to tree height between and among forest types. This information improves our understanding of the distribution of epiphytic lichens in forest ecosystems and the promotion of forest management in subtropical China.

The weight of the crust: Biomass of crustose lichens in tropical dry forest represents more than half of foliar biomass

“…Interestingly, all of them are for tropical montane forests and their lichen biomass estimates are between 0.003 and 0.2 Mg/ha (Forman, 1975; Gómez González, Rodríguez Quiel, Zotz, & Bader, 2017; Pentecost, 1998; Werner, Homeier, Oesker, & Boy, 2012). On the other hand, lichen biomass in subtropical forests in China can reach values up to 1.18 Mg/ha (Li et al., 2017). Note that one challenge in interpreting the literature is that some studies dealing with epiphyte biomass in the tropics have included lichens, but did not provide a separate value for each epiphyte group and instead, combined lichens with bryophytes or vascular plants (Edwards & Grubb, 1977; Gehrig‐Downie, Obregón, Bendix, & Gradstein, 2011; Hofstede, Dickinson, & Mark, 2001; Nadkarni, Schaefer, Matelson, & Solano, 2004; Wolf, 1993).…”

Dry-Season Fog Water Utilization by Epiphytes in a Subtropical Montane Cloud Forest of Southwest China

“…After checking the normality and the homogeneity of variances using the Shapiro-Wilk test and Bartlett's test respectively, the assumptions of one-way Analysis of Variance for some data (i.e., the δ 2 H, δ 18 O and δ 13 C of epiphytes, and the δ 18 O of potential water sources) could not be satisfied even after transformation. Thus, a nonparametric Kruskal-Wallis rank-sum test, followed by the pair-wise Wilcoxon rank-sum test, were used to test for differences of δ 2 H, δ 18 O, and δ 13 C in epiphytes, and the δ 2 H and δ 18 O in potential water sources [59]. To test the effects of δ 2 H and δ 18 O on δ 13 C (WUE i ) in different groups of epiphytes (i.e., epiphytic lichens, epiphytic bryophytes, epiphytic ferns, and epiphytic seed plants) linear mixed model (LMM) was used with the R package 'lme4' [60], in which the δ 2 H and δ 18 O of different groups were treated as fixed effects.…”

Patterns of lichen richness across elevation in the Manaslu Conservation Area, central Nepal

“…This pattern, often referred to as the mid-elevation peak, is thought to arise due to a combination of various factors, including climatic conditions, habitat complexity, and the presence of specific microhabitats. However, it is essential to note that the elevational lichen richness patterns can be influenced by regional and local factors, such as forest types and anthropogenic disturbances [10,11].…”