Figure Captions
Figure 1. Proportion of sampled unfenced plants with deer browse signs
in the understory of a central New Jersey suburban forest, Herrontown
Woods Preserve. LIBE, Lindera benzoin ; NYSY, Nyssa
sylvatica ; EUAL, Euonymus alatus ; ROMU, Rosa multifloraNumber of sampled plants from right to left: LIBE, 30, 476; NYSY, 29,
308; EUAL, 80, 743; ROMU, 55, 492. G-tests for heterogeneity indicated a
significant difference among species only for the pooled 2012-2019 data;
different letters indicate species that were significantly different (P< 0.02) in pairwise tests.
Figure 2. Comparison of the metabolite profiles of the tree species in
the fenced and unfenced plots. A) The number of common and unique
metabolite features identified for the four woody tree species is
depicted in the Venn diagram. B) Principal component analysis (PCA)
depicts the clustering of all the samples based on species. C)
Dendrogram displays the relationship of the samples based on genotype
and presence or absence of fences. D) Common and unique metabolic
pathways predicted based on the differentially accumulating metabolites.
Figure 3. Identification of metabolites that accumulate differentially
in the four species following the treatment gradient. A) Partial least
squares discriminant analysis (PLS-DA) separates the samples into eight
distinct groups corresponding to species and containment in fence or
unfenced plots. B) Important features that contributed to the PLS-DA
based separation of the samples are depicted with their pattern of
accumulation shown by the color code. C) Normalized concentrations (mean+ SE) of the top five metabolite features identified by PLS-DA.
Different letters indicate statistically significant differences (ANOVA
and Tukey’s HSD).
Figure 4. Untargeted metabolomic analysis of N. sylvatica samples
from fenced and open plots. A) Principal component analysis (PCA)
grouped the samples into two clusters that correspond with the fencing
treatment. B) PLS-DA clustering identified two distinct groups based on
treatment. C) The top 15 metabolite features that contributed to the
separation of the samples into two clusters on the PLS-DA plot and their
relative abundances is shown. D) Hierarchical cluster analysis (HCA)
computed based on the top 30 significantly different metabolite features
groups the samples into two groups.
Figure 5. Metabolomic comparison of fenced and unfenced L.
benzoin samples. A) PCA plot demonstrates the metabolite-based
relationship of the fenced and unfenced L. benzoin samples. B)
PLS-DA plot clusters L. benzoin samples into two groups based on
significant features. C) The top 15 metabolite features that are
responsible for the PLS-DA grouping of the samples and their relative
abundances in fenced and unfenced plants is displayed. D) Pearson
Correlation and HCA identified the top 25 metabolites that varied
significantly among the samples and clustered the sampled into groups
based on these features.
Figure 6. Untargeted metabolomic analysis of R. multiflora under
fenced and unfenced plots. A) PCA plot displays the similarities and
differences of R. multiflora samples based on the identified
metabolite features. B) PLS-DA identifies two clusters that correspond
to treatments. C) Important features that differentiate the samples into
fenced and unfenced groups. D) HCA displays the top 25 significantly
different metabolites and their relative abundances among the R.
multiflora samples.
Figure 7. Comparative metabolomic analysis of E. alatus samples
from fenced and open plots. A) PCA indicates no treatment-based
clustering of the samples. B) PLS-DA clusters the E. alatussamples into two treatment-related groups. C) Fifteen of the top most
important features were identified by PLS-DA analysis and their relative
abundances in fenced and unfenced plots are shown. D) HCA depicts the
relative concentrations of the top 25 metabolite features that differed
among the fenced and unfenced samples significantly.
Figure 8. Means + 95% CL of percent cover and height of four
woody and semi-woody species in the understory of a central New Jersey
suburban forest, Herrontown Woods Preserve, in fall 2019. Fenced plots
had excluded deer since spring 2013. LIBE, Lindera benzoin ; NYSY,Nyssa sylvatica ; EUAL, Euonymus alatus ; ROMU, Rosa
multiflora . Top, N fenced = 18, N not fenced = 20. Bottom, N from left
to right: 23, 41, 14, 5, 65, 18, 11, 17. * P<0.05,
**P<0.01, ****P<0.0001, from one-tailed t-tests
between fenced and no-fenced values for each species.
Figure 9. Phylogenetic relatedness of the four species included in the
study. Species Order classifications are from the Integrated Taxonomic
Information System (http://www.itis.gov), and the Order-level tree is
from the Angiosperm Phylogeny Website
(http://www.mobot.org/MOBOT/research/APweb/).