Change of epiphyllous population occupancy patterns in fifteen
years
For both species (R. flaccida and C. surinamensis ) we
observed changes in the estimated number of colonies censused per 1-ha
plot in a 15-year interval (Figure 2A-B; Table 1; Table S3).
Specifically, the number of colonies of R. flaccida increased
significantly in small patches (1- and 10-ha) across all study plots:
average increases from 53.03 to 176.89 (W = 2, p-value =
0.002). Among large patches, the number of colonies either increased or
decreased over time, with a non-significant overall average increase
from 284.29 to 338.42 (W = 47, p-value = 0.16). Similarly,
the number of colonies of C. surinamensis increased in small
patches in all study plots, with a significant average increase from
33.04 to 198.27 (W = 0, p-value = 0.0005). In large
patches, the number of colonies presented a slightly significant average
increase from 250.83 to 397.72 (W = 33, p-value = 0.02).
In the year 2000, the estimated number of colonies in all small patches
(1- and 10-ha) was significantly reduced when compared to large patches
(Figure 2C in 2000, R. flaccida : W = 86, p-value =
0.0004; C. surinamensis : W = 85, p-value = 0.0007).
The estimated number of colonies in small patches (1- and 10-ha)
remained reduced in 2016 when compared to large patches of 100-ha and
continuous forests (Figure 2C in 2016; R. flaccida : W =
112, p-value = 0.006; C. surinamensis : W = 113,p-value = 0.005). When only 10-ha patches were compared to larger
patches they harbored in 2000 significantly fewer epiphyllous colonies
(R. flaccida : W = 49, p-value = 0.005; C.
surinamensis : W = 47, p-value = 0.015). In the year 2016,
these 10-ha patches present a similar number of colonies compared with
larger patches (R. flaccida : W = 53, p-value =
0.19; C. surinamensis : W = 53, p-value = 0.19)
(Table 1).