10.5061/DRYAD.2NGF1VHKG
Camargo, Paulo H. S. A.
0000-0001-9081-4558
Sao Paulo State University
Pizo, Marco A.
Sao Paulo State University
Brancalion, Pedro H. S.
University of Sao Paulo
Carlo, Tomás A.
Pennsylvania State University
Data from: Fruit traits of pioneer trees structure seed dispersal across
distances on tropical deforested landscapes: implications for restoration
Dryad
dataset
2020
Coordenação de Aperfeicoamento de Pessoal de Nível Superior
https://ror.org/00x0ma614
Finance Code 001
São Paulo Research Foundation
https://ror.org/02ddkpn78
2016/17194-0
National Council for Scientific and Technological Development
https://ror.org/03swz6y49
National Science Foundation
https://ror.org/021nxhr62
DEB-1556719
2020-06-22T00:00:00Z
2020-06-22T00:00:00Z
en
173706 bytes
2
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Pioneer trees with fleshy fruits are typically planted in restoration
projects to attract frugivores as a mean to increase dispersal and
accelerate forest regeneration. However, differences in fruit traits of
pioneer trees can potentially influence dispersal and their restoration
outcomes. Here we investigated the effects of bird and plant traits, and
distance to forest fragments, on the seed rain using a tree-planting
experiment replicated in 12 deforested sites in Brazil. Factors were fruit
traits of pioneer trees (wind-dispersed, bird-dispersed with lipids or
with carbohydrates, and controls) and distance (10, 50, 300 m) from forest
fragments. We found that density and richness of birds and seeds decreased
exponentially with distance from fragments, yet these effects were minor
compared to the effects of fruit traits on the structure of the seed rain.
Overall, plots with fleshy-fruited pioneers attracted much greater bird
activity and seed dispersal than plots with wind-dispersal pioneers and
the controls. For instance, plots with carbohydrate-rich fruits received
more than twice the average species richness and density of birds and
seeds of plots with lipid-rich pioneer trees, surpassing wind-dispersed
pioneers by more than 80%, and controls by over 90%. Furthermore, the
fruit trait treatments resulted in morphological shifts in the average
traits of visiting birds. Significant differences in bill gape and flight
capacities (wing-loading) were associated with the differences in the seed
rain associated with each treatments. Synthesis and applications.
Understanding how trait-matching processes mediating mutualistic seed
dispersal by frugivores interact with distance-dependent dispersal
limitation on deforested tropical landscapes is critical for improving
forest restoration efforts. This is especially relevant in the context of
applied nucleation. As shown here, avian seed dispersal can thus be
manipulated in restoration projects in order to increase connectivity and
speed up forest recovery and the provision of the multiple ecosystem
services that follow forest succession.
Study sites We conducted the experiment in 12 sites in Paranapanema, São
Paulo, Brazil (23°23'S, 48°43'W, Fig. 1). Paranapanema is
located at ca. 600 m a.s.l. on the watershed region of the Alto
Paranapanema river (Cielo-Filho et al., 2009). Average precipitation is
1.407,9 mm mostly during December-March, and a mean temperature of 18 °C
(Cielo-Filho et al., 2009). Atlantic forest fragments cover ~6% of the
Paranapanema landscape (Fundação SOS Mata Atlântica, 2013). Our study
sites were located on private cattle pastures and fragments of primary and
secondary semideciduous forest >30 years old and 12.2-98.8 ha in
size. Experiment set up Between December 2016 and November 2018 we
conducted a full-factorial experiment using two explanatory variables:
distance to forest fragment at three levels: 10, 50, 300 m, and fruit
traits of pioneer trees at three levels: Heliocarpus popayanensis Kunth
with wind-dispersed fruits, Acnistus arborescens Schltdl, with
bird-dispersed fruits, and Trema micrantha (L.) Blume also with
bird-dispersed fruits, plus a control treatment without any tree. Thus,
the 4 x 3 design yielded 12 types of plots that were replicated once in
each of 12 localities in Paranapanema, totaling 144 (Fig. 1). The relative
position of each Fruit trait treatment plot was randomly determined within
each distance class, and spaced the others by a distance equal to their
distance to the from fragments. The two bird-dispersed trees (Acnistus
& Trema) differed in their fruit traits: Acnistus has larger
carbohydrate-rich fruits, while Trema has small lipid-rich fruits (See
Table S1). Plots measured 4.5 x 4.5 meters and were fenced with barbwire
to keep cattle out (Fig. S1). Pioneer trees from all species had similar
height, crown, and fruit crop (Tables S1-S2) and were grown nurseries
until a height of ~1.5 m. A single tree was planted at the center of plots
requiring trees, and fertilized with 300 g of 15-18-28 (NPK) every six
months. Grasses were mechanically controlled during the entire experiment.
Bird activity We recorded bird visits in all experimental plots using a
combination of video recording and focal observation with effort equally
distributed among plots. We used 28 video cameras from four different
brands (ten Bushnell Trophy Cam, six Bushnell Trophy Cam HD, six Tigrinus,
and six GoPro Hero 3). Camera traps operated 24 h/day recording 88,714.7
h, while the GoPro Hero 3 cameras filmed for 2 hours per day for, 288 h.
To prevent sampling bias associated with camera models, all units were
systematically rotated to sample for the same amount of time in each
experimental plot across the twelve study sites. In addition, in each plot
one observer (P. Camargo) recorded bird visits using a pair of binoculars
from a distance of 50m for 20 minutes, during morning hours (0730-1030),
once a month, for 5 months. Seed rain We sampled the seed rain of all
plots using one 0.25-m² seed trap lined with a 0.2-mm nylon mesh and
located at the center of the enclosure and covered with a 2.5 x 2.5 cm
wire mesh (Fig. S1). The sticky paste Formifuu® was applied to the support
posts of traps to exclude ants. Traps were collected each month and seeds
counted and identified with the aid of a dissecting scope and reference
books and seed collections. Seeds from grasses or from the species of the
pioneer tree species in a plot were excluded from analyses. Bird and
seed traits Bird traits included % fruit in diet (Wilman et al. 2014),
wing-loading as a proxy of bird movement capacity, and gape-width as a
proxy to their upper seed size dispersal potential. Wing-loading was
calculated as: WLo= BM2×WL where BM is the bird body mass and WL is wing
length (species measurements were obtained from Rodrigues et al. 2019). As
loading value increases, the movement capacity of a bird species
decreases. We classified dispersed seeds by dispersal mode:
bird-dispersed, wind-dispersed, and gravity-dispersed. In addition, we
calculated seed mass and approximated lipid content of fruit in a rank
scale (1 - 0 to 10% lipids, 2 - 10 to 20%, 3 - 20 to 30% and 4 - above
30%) adapted from Bello et al. (2017).