DOI: 10.5061/dryad.q2bvq83v0
title: Retention forestry can maintain epiphytic lichens on living pine trees, but provides impoverished habitat for deadwood-associated lichens

description: Managing forests for timber yields reduces the amounts of old trees and
 deadwood, which has profound effects on species that are dependent on
 them. Retention forestry, where some trees are permanently left
 unharvested on clearcut sites, may enable the formation of deadwood and
 old trees in managed forests, but it is unresolved how well these
 practices facilitate the occurrence of species in managed forests,
 especially in the long term. We studied the capacity of tree
 retention practices to support the diversity of epiphytic lichens, a key
 group among threatened forest species. We compared lichen assemblages on
 retained trees in harvested sites to those on trees in unharvested control
 sites. The data was collected 21 years post-harvest and included living
 trees, snags (standing dead trees), and logs (fallen trees) of Pinus
 sylvestris (Scots pine). Living trees, snags, and logs each hosted
 distinct lichen communities. The highest lichen diversity was found on
 snags. On living trees, species richness was similar in harvested and
 unharvested sites, but there was slight species turnover. In contrast,
 deadwood in unharvested sites hosted higher species richness and distinct
 species assemblages compared to deadwood in harvested sites. These
 differences were most pronounced on snags. Specifically, unharvested sites
 contained high-longevity snags (kelo trees), which hosted unique lichen
 communities with higher lichen richness than any other studied substrate,
 including the highest numbers of red-listed and deadwood-dependent
 species. Synthesis and applications: Retention forestry can support lichen
 assemblages associated with living Pinus sylvestris. However, maintaining
 deadwood-associated lichen diversity through retention practices entails
 significant challenges. Deadwood-associated lichen diversity relies on
 high-longevity snags and is not sustained by the habitats provided in
 retention forestry. Biodiversity maintenance in forest management requires
 comprehensive provision of the habitat features of unmanaged forests, such
 as a qualitatively representative deadwood profile, which can prove
 difficult.
description: # Retention forestry can maintain epiphytic lichens on living pine trees,
 but provides impoverished habitat for deadwood-associated lichens
 [https://doi.org/10.5061/dryad.q2bvq83v0](https://doi.org/10.5061/dryad.q2bvq83v0) ## Description of the data and file structure The data was collected in the context of a field experiment, where overmature pine-dominated (*Pinus sylvestris*) forests in boreal Finland were harvested with different treatments. The three treatments included in this data set are: Unharvested (i.e. control), 50H (harvested with 50 m3/ha of retained trees), 10H (harvested with 10 m3/ha of retained trees). The data consists of presence-absence lichen community data surveyed on 396 that include living trees, standing dead trees (snags), and fallen dead trees (logs). These also include 30 kelo trees, i.e. a special type of standing dead tree with exceptional longevity, that were located in or in the vicinity of the control sites. All surveyed trees were Scots pines (*Pinus sylvestris*). ### Files and variables #### File: Nirhamo\_et\_al\_Data.xlsx **Description:** Presence-absence community data of lichens on the surveyed trees. Each row corresponds to one surveyed tree. ##### Variables * Site_no: An identifier for which site the surveyed tree was located in. * Treatment: The treatment that was applied in the site where the surveyed tree was located. * Tree_type: The tree type of the surveyed tree; Living, Snag, Log, or Kelo. * SpRichness: The total number of lichen species observed on the surveyed tree. * RedList: The total number of lichen species that are nationally red-listed in Finland, according to the IUCN Red List criteria, that were observed on the surveyed tree. * DWDep: The total number of deadwood-dependent lichen species that were observed on the surveyed tree. * Rest of the columns: Lichen species that were observed in this study, sorted alphabetically. "0" indicates the species was not observed on the surveyed tree (absence), "1" indicates that the species was observed on the surveyed tree (presence). ## Code/software MS Excel, Google Sheets, or similar spreadsheet editor software.