DOI: 10.5061/dryad.sxksn02zc
title: Trophic rewilding revives biotic resistance to shrub invasion

description: Trophic rewilding seeks to rehabilitate degraded ecosystems by
 repopulating them with large animals, thereby reestablishing strong
 top-down interactions. Yet there are vanishingly few tests of whether such
 initiatives can restore ecosystem structure and functions, and on what
 timescales. Here we show that war-induced collapse of large-mammal
 populations in Mozambique’s Gorongosa National Park exacerbated woody
 encroachment by the invasive shrub Mimosa pigra—one of the
 world’s ‘100 worst’ invasive species—and that one decade of concerted
 trophic rewilding restored this invasion to pre-war baseline levels.
 Mimosa occurrence increased between 1972 and 2015, a period encompassing
 the near-extirpation of large herbivores during the Mozambican Civil War.
 From 2015–2019, mimosa abundance declined as ungulate biomass recovered.
 DNA metabarcoding revealed that ruminant herbivores fed heavily on mimosa,
 and experimental exclosures confirmed the causal role of mammalian
 herbivory in containing shrub encroachment. Our results provide
 mechanistic evidence that trophic rewilding has rapidly revived biotic
 resistance to a notorious woody invader, underscoring the potential for
 restoring ecosystem structure and functions in degraded African protected
 areas.
description: This study was conducted in Gorongosa National Park,
 Mozambique. Post-war field data on Mimosa pigra were
 obtained from plant surveys (2011-2019) and exclosure experiments
 (2015-2018) conducted in the Urema Lake floodplain. Pre-war data were
 extracted from Tinley (1977) "Framework of the Gorongosa ecosystem,
 Mozambique" Raw diet data from 2013 to 2018 have
 been obtained by fecal DNA metabarcoding and high-throughput sequencing.
 The P6 loop of the chloroplast <i>trn</i>L (UAA) intron was
 amplified using the universal primers “g” (5’-GGGCAATCCTGAGCCAA-3’) and
 “h” (5’-CCATTGAGTCTCTGCACCTATC-3’) (Taberlet et al. 2007). Amplicons were
 sequences on Illumina HiSeq 2500 platform (170 bp single-end sequencing in
 2013 and 2 x 150 bp paired-end sequencing in 2015-1018). Initial
 processing steps were performed using the OBITOOLS software
 (http://metabarcoding.org/obitools) as follows: (i) Direct and reverse
 reads corresponding to the same sequence were aligned and merged thanks to
 the ‘<i>illuminapairedend</i>’ program. Only merged sequences
 with a high alignment quality score were retained (&gt;=40). (ii) Each
 merged sequence was assigned to its original sample using the tags
 information previously added to primers using the
 ‘<i>ngsfilter</i>’ program. Only sequences containing both
 primers (with a maximum of 2 mismatches per primer) and exact tag
 sequences were selected. (iii) Strictly identical sequences were merged
 together while keeping information about the origin of
 sequences. Users of the raw dietary data are requested
 to coordinate with the corresponding author (rpringle@princeton.edu) to help
 ensure accurate interpretation and avoid duplication with other research
 in progress.
description: <b>Raw diet data 2013</b> This
 fasta file contains unfiltered sequencing data (i.e. merged paired-end
 reads assigned to their original sample) from fecal samples collected in
 2013. Diet_GNP13_trnL_raw_data.fasta.gz
 README_Diet_GNP13_trnL_raw_data.txt Metadata
 fecal samples 2013 This file contains metadata
 associated to fecal samples collected in 2013.
 Metadata_fecal_samples_GNP13.csv
 README_Metadata_fecal_samples_GNP13.txt
 <b>Raw diet data 2015</b> This
 fasta file contains unfiltered sequencing data (i.e. merged paired-end
 reads assigned to their original sample) from fecal samples collected in
 2015. Diet_GNP15_trnL_raw_data.fasta.gz
 README_Diet_GNP15_trnL_raw_data.txt Metadata
 fecal samples 2015 This file contains metadata
 associated to fecal samples collected in 2015.
 Metadata_fecal_samples_GNP15.csv
 README_Metadata_fecal_samples_GNP15.txt
 <b>Raw diet data 2017 (early and late dry
 seasons)</b> This fasta file contains unfiltered
 sequencing data (i.e. merged paired-end reads assigned to their original
 sample) from fecal samples collected during early (June-August) and late
 (October-November) dry seasons 2017.
 Diet_GNP17_trnL_raw_data.fasta.gz
 README_Diet_GNP17_trnL_raw_data.txt Metadata
 fecal samples 2017 This file contains metadata
 associated to fecal samples collected in 2017 (both early and dry
 seasons). Metadata_fecal_samples_GNP17.csv
 README_Metadata_fecal_samples_GNP17.txt
 <b>Raw diet data </b><b>early dry season
 2018</b> This fasta file contains unfiltered
 sequencing data (i.e. merged paired-end reads assigned to their original
 sample) from fecal samples collected in the early dry season (June-August)
 2018.
 Diet_GNP18_EarlyDrySeason_trnL_raw_data.fasta.gz
 README_Diet_GNP18_EarlyDrySeason_trnL_raw_data.txt
 Metadata fecal samples early dry season 2018
 This file contains metadata associated to fecal samples collected
 in the early dry season 2018.
 Metadata_fecal_samples_GNP18_EarlyDrySeason.csv
 README_Metadata_fecal_samples_GNP18_EarlyDrySeason.txt
 <b>Raw diet data late dry season 2018</b>
 This fasta file contains unfiltered sequencing data (i.e. merged
 paired-end reads assigned to their original sample) from fecal samples
 collected in the late dry season (October-November) 2018.
 Diet_GNP18_LateDrySeason_trnL_raw_data.fasta.gz
 README_Diet_GNP18_LateDrySeason_trnL_raw_data.txt
 Metadata fecal samples late dry season 2018
 This file contains metadata associated to fecal samples collected
 in the late dry season 2018.
 Metadata_fecal_samples_GNP18_LateDrySeason.csv
 README_Metadata_fecal_samples_GNP18_LateDrySeason.txt
 Mimosa consumption data This table presents
 the mean relative read abundance and the frequency of occurrence of Mimosa
 pigra in the diet of the six dominant floodplain large herbivores between
 2013 and 2018. These data correspond to Fig. 3 and Extended Data
 2. Mimosa_RRA_FOO.csv
 README_Mimosa_RRA_FOO.txt Most abundant plant
 items in large herbivores diet These tables present
 the 10 most abundant mOTUs identified in the diet of the six dominant
 floodplain large herbivoresspecies for each sampling season (from 2013 to
 2018). One sheet per sampling season (2013, 2015, 2016, 2017 early dry
 season, 2017 late dry season, 2017 early dry season and 2018 late dry
 season). These data correspond to Extended Data 1.
 Most_Abundant_mOTUs_per _species.xlsx README_
 Most_Abundant_mOTUs_per_species.txt Field
 data This file contains the following field data
 (corresponding to Supplementary data 1-8, one sheet per
 dataset): (i) Biomass density of large herbivores in
 Gorongosa's Urema Floodplain between 1969 and 2018. These data
 correspond to Fig. 2a. (ii) Mimosa occurrence in 18
 long-term floodplain monitoring plots between 1972 and 2017. These data
 correspond to Fig. 2b. (iii) Rainfall measured at
 Gorongosa’s Chitengo camp between 1957 and 2019. These data correspond to
 Fig. 2c,d. (iv) Mimosa density in four
 200-m<sup>2</sup> floodplain plots between 2011 and 2019.
 These data correspond to Fig. 2d. (v) Size, survival,
 and reproduction of tagged mimosa plants in experimental plots over six
 surveys between 2015 and 2018. These data correspond to Fig. 4a-d, f and
 Extended Data 3. (vi) Recruitment of mimosa seedlings
 and saplings in experimental plots in September 2017. These data
 correspond to Fig. 4e. (vii) Total survey of mimosa
 abundance and biomass in experimental plots in August 2018. These data
 correspond to Fig. 5. (viii) Estimation of mimosa
 aboveground dry biomass from canopy dimensions. These data correspond to
 Extended Data 4.
 Supplementary_Field_Data.xlsx
 README_Supplementary_Field_Data.txt