DOI: 10.5061/dryad.8kprr4xvb
title: Restoration opportunities beyond highly degraded tropical forests: insights from India’s Western Ghats

description: Tropical rainforest remnants in human-modified landscapes exhibit varying
 levels of degradation, from highly degraded open-canopied and invasive
 plant-invaded habitats to closed-canopy forests that appear structurally
 intact. The former are frequently identified as being in a state of
 arrested recovery, and targeted for restoration, but restoration needs and
 opportunities in the latter remain underexplored. Using tree and seedling
 data from 105 plots spanning a canopy cover gradient in rainforest
 fragments and 19 plots in relatively intact “reference” rainforests in
 India’s Western Ghats mountains, we show that the floristic composition,
 conservation significance, and carbon stocks of closed-canopy fragments
 (CC) more closely resemble open-canopy fragments (OC) than reference
 rainforests (RR). For example, densities of old-growth forest species,
 endemic/threatened species, and carbon stocks, increased from 15%, 28%,
 and 22% of reference values in OC to 32%, 46%, and 35% in CC,
 respectively, while tree community similarity to RR showed no increase
 from OC to CC (15%). Seedlings mirrored this pattern, offering little
 indication of natural recovery in closed-canopy fragments. Further, we
 show using simulations that seedling enrichment in closed-canopy fragments
 can initiate varying levels of floristic and functional recovery towards
 reference targets. Our findings illustrate that seemingly structurally
 intact tropical rainforest fragments can remain arrested in a
 floristically degraded condition, and represent worthwhile targets for
 ecological restoration. Such forests expand opportunities for restoring
 conservation-priority and high carbon-storing species using relatively
 low-cost methods (e.g., enrichment planting), which can complement
 intensive restoration of highly degraded forests and minimally-assisted
 natural recovery of less-fragmented forests.
description: # Restoration opportunities beyond highly degraded tropical forests:
 insights from India’s Western Ghats
 [https://doi.org/10.5061/dryad.8kprr4xvb](https://doi.org/10.5061/dryad.8kprr4xvb) This document describes the data and scripts associated with Osuri et al. 2024: Restoration opportunities beyond highly degraded tropical forests: insights from India’s Western Ghats The upload contains three data files and four R scripts. ## Description of the data and file structure 1\. **Osuri_tree_data.csv** contains data from 132 tree (GBH &gt;=30 cm) inventory plots (20m x 20m) in rainforest fragments and reference rainforests. 124 plots were analyzed, while 8 plots lacking canopy cover data were excluded. The data columns are: DateTime: Date/timestamp Treatment: Forest fragmentation status -- Fragment OR Benchmark (reference) Site_ID: Unique site code for each plot Species_name: Species name as recorded Height: Tree height (m) GBH1: Girth at breast height (cm) of single-stemmed trees GBH1 - GBH12: Girth at breast height (cm) of multi-stemmed trees Remarks: Remarks Accept_name_WFO: World Flora Online accepted species names Habit: Growth form -- Tree OR Shrub Distribution: Distributional range and origin -- Endemic OR Native OR Introduced IUCN_status: IUCN redlist category -- CR or EN or VU or NT or LC or DD, or NA (unknown) wden_sps: Species-level wood density (g cm-3) Wden_final: Wood density (g cm-3) used in biomass estimation, species level is available, else genus level seed_size: Categorical -- S (Small; length &lt;1 cm), M (Medium; length 1-3 cm), L (Large; length &gt;3 cm), or NA (Unknown) disperser: Seed dispersal mechanism -- Bird, Mammal, Mammal_bird (mammal and bird), Gravity, Wind, or Unknown habt_new: Habitat affinity category: Mature (mature forest), Secondary (secondary or disturbed forest), NA (unknown/Introduced species) ad_ht: Species maximum adult height (m) DBH: Effective diameter (cm). Calculated as (d1^2 + d2^2 +...dn^2)^0.5, where d1 = GBH1/pi, and so on Basal: Tree basal area (m2) Carbon: Tree aboveground carbon stock (Mg) 2\. **Osuri_regen_data.csv** contains data from 132 seedling (height &gt;= 10 cm and GBH &lt; 10 cm) plots (20m x 20m) in rainforest fragments and reference rainforests. 124 plots were analyzed, while 8 plots lacking canopy cover data were excluded. The data columns are: Date: Date/timestamp Site_ID: Unique site code for each plot Treatment: Forest fragmentation status -- Fragment OR Benchmark (reference) Species_name: Species name as recorded Abun: No. of individuals counted Accept_name_WFO: World Flora Online accepted species names Habit: Growth form -- Tree OR Shrub Distribution: Distributional range and origin -- Endemic OR Native OR Introduced IUCN_status: IUCN redlist category -- CR or EN or VU or NT or LC or DD, or NA (unknown) wden_sps: Species-level wood density (g cm-3) Wden_final: Wood density (g cm-3) used in biomass estimation, species level is available, else genus level seed_size: Categorical -- S (Small; length &lt;1 cm), M (Medium; length 1-3 cm), L (Large; length &gt;3 cm), or NA (Unknown) disperser: Seed dispersal mechanism -- Bird, Mammal, Mammal_bird (mammal and bird), Gravity, Wind, or Unknown habt_new: Habitat affinity category: Mature (mature forest), Secondary (secondary or disturbed forest), NA (unknown/Introduced species) ad_ht: Species maximum adult height (m) **3. Osuri_plotInfo.csv** contains site details of 132 plots, 124 of which were included in the analysis. The data columns are: S_No.: Serial number Site_name: Site name Site_ID: Unique site code for each plot Treatment: Forest fragmentation status -- Fragment OR Benchmark (reference) Lat_final: Latitude of plot centroid (degree-decimal) Long_final: Longitude of plot centroid (degree-decimal) dist_PA: Distance from protected area (m) CanCover: Canopy cover (%) ## Sharing/Access information For tree functional trait data and sources, see Osuri et. al. (2024) Fruit, seed dispersal, and life history traits of tropical rainforest trees of the Anamalai Hills, Western Ghats, India ## Code/Software 1\. Osuri_tree_script.R contains R scripts for computing summaries, performing regression models, and creating graphs from the adult tree dataset (outputs: Fig. 2, Fig. S3, Fig. S5, Table S2) 2\. Osuri_regen_script.R contains R scripts for computing summaries, performing regression models, and creating graphs from the regeneration dataset (outputs: Fig. 2, Fig. S4, Fig. S5, Table S3) 3\. Osuri_simulation_script.R contains R scripts for performing the restoration simulations using the tree and regeneration datasets, and generating Fig. 3 4\. Osuri_figure_composites.R contains R scripts for formatting Figs. 2, 3, S3, S4, and S5 as depicted in the manuscript