To What Extent Local Forest Soil Pollen Can Assist Restoration in Subtropical China?

Abstract

Long-term ecological data play a vital role in ecological conservation and restoration, however, using information from local forest soil pollen data to assist restoration remains a challenge. This study analyzed two data sets, including 1) surface soil pollen (0–5 cm) and current vegetation data from four near-natural communities and four plantations, and 2) fossil pollen from soil profiles (0–80 cm) from a regional climax community and a degraded land. The pollen representativeness and similarity indexes were calculated. The results showed a low similarity between soil pollen and current vegetation (about 20%) thus forest soil pollen data should be used with caution when defining reference ecosystems. Pollen from Gironniera and Rutaceae which were abundant in broadleaved forest, were also detected in the 40–80 cm layer of a soil profile from the degraded land, which indicates its restoration possibility. Our study considered that the early restoration stage of the study area may benefit from using plant taxa of Pinus, Poaceae, Lonicera, Casuarina, Trema and Quercus. As Pinus, Castanopsis, Gironniera, Rutaceae, Helicia, Randia, Poaceae, Dicranopteris and Pteris always existed during succession, for regional forest restoration under global climate change, the roles of such “stable species” should be considered.

Improving Ecological Restoration to Curb Biotic Invasion—A Practical Guide

“…). In addition to nearby natural vegetation (if available), records of historical vegetation (before massive human alternation) could be used as a potential target and, in some cases, soil pollen may also inform restoration plans and strategies, as indicated by a few more recent studies describing ecological memory theory (Sun et al 2014(Sun et al , 2016. The boundary conditions outside the site being restored should also be assessed in case additional actions (e.g., fences, buffer zones) are needed ( Figure 3).…”

“…For sites with existing vegetation, the following procedure can be used as a reference before restoration begins: (1) conduct a comprehensive site assessment, including an inventory both aboveground (existing vegetation) and belowground (seedbanks) for native and exotic species (Chiquoine and Abella 2018; Thilmony and Lym 2017; Wang et al 2009, 2015), with both domestic and foreign exotic and invasive species identified in local and regional species pools (Guo and Ricklefs 2010); (2) measure and rank exotic species, especially invasive species, based on their relative abundance, such as biomass and cover; and (3) establish a reasonable restoration goal based on the present condition and available resources (consider funding, available labor, existing species pools, historic vegetation, etc.). In addition to nearby natural vegetation (if available), records of historical vegetation (before massive human alternation) could be used as a potential target and, in some cases, soil pollen may also inform restoration plans and strategies, as indicated by a few more recent studies describing ecological memory theory (Sun et al 2014, 2016). The boundary conditions outside the site being restored should also be assessed in case additional actions (e.g., fences, buffer zones) are needed (Figure 3).…”

“…When large areas of natural or historical vegetation have been destroyed or severely degraded, it can be challenging to establish a desired target condition for restoration. In such cases, ecological memory could be used through building a historical pollen spectrum (Sun et al 2014, 2016). This approach can help in developing a more complete native species list, but historical climate shifts need to be taken into account.…”

Rethinking the Ecosystem Functions of Dicranopteris, a Widespread Genus of Ferns

“…The current presence of Dicranopteris , in contrast, indicates early stages of succession in tropical and subtropical forests. Dicranopteris spores are consistently found in various strata, suggesting the important role of these species in the past ( Sun et al, 2016 ). Big data regarding Dicranopteris from worldwide strata should be reanalyzed, and ancient and modern data should be combined to determine how the ecological roles of Dicranopteris species may change in the future.…”

Phytolith Assemblages as a Promising Tool for Quantitative Canopy Coverage Reconstruction in Subtropical Forests, China

“…Poaceae pollen is moderately representative of Poaceae (with R value close to 1, cf. Sun et al, 2016;Jiang et al, 2020), and this explains why Poaceae pollen is a relatively good indicator of vegetation composition.…”