DOI: 10.5061/dryad.d2547d84z
title: Landscape conservation as a strategy for recovering biodiversity: lessons from a long-term program of pasture restoration in the southern Atlantic Forest

description: Although ecological restoration has entered the global agenda to reverse
 different anthropogenic disturbances, we still know little about how this
 solution interacts with other conservation strategies, to avoid the
 progressive loss of species and ecosystem services. Here we evaluate one
 of the pioneering restoration programs in the southern Brazilian Atlantic
 Forest, where the combination of conservation and restoration efforts have
 been carried out for 20 years. Specifically, we tested how landscape
 characteristics, restoration strategies  and environmental
 characteristics affect the results of the restoration of pastures. We
 established 65 circular plots (total 4.0 ha) along restoration areas (3-10
 years) and sampled trees and shrubs composing the canopy (DBH &gt;
 5cm) and understory (DBH&lt; 5cm, height &gt; 1.3m). We analyzed
 the landscape metrics (proportion of old-growth forests in 200 m, 500m and
 1000m buffers around each plot; and area and distance of the
 nearest-neighboring old-growth forests). We explored the multiple effects
 of landscape, restoration strategy (reforestation, natural regeneration)
 and environmental variables (soil, pasture grass types) on the species
 composition and multiple diversity metrics of restoration areas. The
 species composition was very similar among restoration ages and
 restoration strategies. We found positive and strong effects of old-growth
 forest (200 m buffer) proportion on the species richness and Shannon
 diversity (canopy and understory), aboveground biomass (canopy) and
 functional diversity (understory) of restoration areas. The restoration
 strategies affected forest structure, and, in general, the reforestation
 strategy increased aboveground biomass, Shannon, functional and
 phylogenetic diversities (in canopy), and percentage of endemic species
 and biomass (understory), when compared to natural regeneration.
   The 20 year-experience in the southern Atlantic Forest showed
 that programs focused on landscape conservation associated with a mixture
 of restoration strategies (i.e. natural regeneration in larger areas and
 active restoration in more disturbed sites) , can be an efficient strategy
 to ensure biodiversity and ecosystem services in tropical landscapes.
 Synthesis and applications: To manage degraded tropical lands and achieve
 global targets for biodiversity and ecosystem services, it is necessary to
 first ensure the conservation of natural remnants and then use multiple
 restoration strategies in less resilient areas.
description: <em>Restoration
 experiment</em><em>: </em>To evaluate the efficiency of the restoration
 strategies used, we carried out an experiment in partnership with SPVS
 that authorized the study within its reserves. The experiment consisted of
 sampling the vegetation in the restored areas in
 <em>Guaricica</em> and <em>das Águas</em> Natural
 Reserves (Figure 1a). We established 65 circular plots (radius of 14m;
 area of 615.7m<sup>2 </sup>each) resulting in a total sampled
 area of 4.0 ha. Plots were distributed in the two reserves and were
 selected in a way to account for a gradient of all variables of pasture
 management techniques, soil and landscape characteristics, and restoration
 strategies (Figure 1b). The plots were established in areas with ages
 varying from 2 to 10 years since the sites were abandoned of agricultural
 use, and in areas with four different soil types (Acrisol, n=6 plots,
 Cambisol, n=15, Gleysol, n=38, and Fluvisol, n=6),  two restoration
 strategies (reforestation=24 plots; natural regeneration=41 plots), and 3
 types of grass cover combinations (<em>Urochloa </em>cf
 <em>humidicola</em> and <em>Urochloa arrecta,
 </em>n=23 plots,<em> Paspalum </em>sp., n=16; and mixed
 <em>Urochloa</em> and <em>Paspalum</em>, n=20).
 For the remaining number of sites, we did not have information whether
 exotic grasses were used and, therefore, they were analyzed in a different
 sub-group. The experiment was established in 2010 and since
 then, some other plots have been incorporated into the sample design and
 evaluated in several studies (for example, Cequinel et al. 2018;
 Capellesso et al. 2020). Part of the plots analyzed here (39 plots) were
 also studied by Kauano et al. (2013) regarding to the effects of the
 landscape on the canopy of forests ongoing restoration. In this study, we
 expanded the sample area (here 65 plots) and the vegetation survey (here
 also considered understorey), incorporating, therefore, a greater
 environmental gradient where the restoration took place. This field study
 does not require ethical approval, according to Brazilian
 standards. <em>Landscape
 analysis</em>: The images used in the analysis were obtained
 from overlapping LANDSAT-5-TM images (from 5<sup>th</sup>
 March 2009) with Ortho-rectified aerial photos (from 2001), and official
 Parana state geomorphological maps. From these images, landscape related
 variables were obtained by the application of Vector-based Landscape Analysis Tools (V-Late
 2.0) extension (Lang & Blaschke, 2007) for ArcGis 10.8
 software (see more details
 in Kauano et al., 2013). The landscape surrounding the plots is
 characterized by the presence of young, intermediate and old-growth
 forests, fluvial areas (wetlands) and pasture and agriculture areas. The
 classification of land-use categories was done by visual inspection of
 images associated by comparisons with historical aerial photos. Old-growth
 forest sites were considered the forest remnants where there were no
 signals of intensive logging for the past 80 years.
 In each plot we obtained the following landscape
 metrics: distance and the area of the nearest-neighbouring fragment, and
 proportion of old-growth forest. We chose these metrics because they are
 related to the amount of available habitat, as well as the distance for
 the arrival of propagules, which affects regeneration (Magnago et al.,
 2015). To explore the effects of geographical scales on the proportion of
 old-growth forest, we considered three buffer distances, with 200 m, 500 m
 and 1000 m (in radius) around the central coordinate of each
 plot. Considering the
 total of plots, the distance to the closest old-growth forest remnant
 (nearest-neighbor distance) varied from 12 to 488 m, and the area of this
 remnant varied from 0.36 ha to 4.24
 ha. The proportions of old-growth forests for 200 m buffer
 varied between 0% to 72%, for 500 m buffer varied between 0.13% and 70%,
 and, for the 1000 m buffer, between 8.5% to 60%. 
 <em>Vegetation survey and plant community
 metrics:<strong> </strong></em>In all 65 plots of 14m in radius we sampled all
 trees and shrubs with diameter at breast height (DBH; 1.3m)
 &gt; 5cm, to characterize the canopy. In a smaller
 concentric sub-plot (4m in radius, 50.3m<sup>2</sup>), we
 measured all individuals (tree saplings and shrubs, which will be referred
 to hereafter as “understory”) with DBH &lt; 5.0cm and total height
 &gt;1.30m. For all sampled individuals we
 determined the species name (by comparing with vouchers in herbarium UPCB)
 and measured the DBH (or stem base diameter, for understory) and tree
 total height. The plant communities (canopy and understory)
 present in each plot were analyzed in relation to different biodiversity
 metrics: taxonomic richness (S) and diversity (H’, Shannon’s index),
 functional diversity (FD, Rao's quadratic entropy), and phylogenetic
 diversity (PD, Mean Pairwise Distance). Rao Q is a measure of divergence by average
 functional distance between two individuals (Mouchet et al. 2010) and
 indicates niche complementarity (Ricotta & Moretti, 2011). MPD
 provides a global community structure value (Webb, 2000; Webb et al.,
 2002). Additionally, we
 considered the percentage of endemic species (%_end) of Atlantic Forest
 and aboveground biomass (Biom, Mg ha-1), in order to represent multiple
 dimensions of biodiversity. Functional diversity was calculated using the
 following plant traits: specific leaf area (SLA, cm2 g-1), leaf dry-matter content (LDMC, mg
 g-1), wood density (WD, g cm3), and maximum height (Hmax, m). All traits were
 measured based on locally collected samples whenever possible, following
 standardized protocols (Pérez-Harguindeguy et al., 2013, see details in
 Capellesso et al. 2020). The PD was based on the built of ultrametric
 phylogeny for tree species (see Supporting Information for
 details). Aboveground
 biomass was calculated following the general wet tropical forest formulae
 provided by Chave et al. (2014).
description: All data are in Excell and can be converted to other
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