Agriculture Reference
In-Depth Information
16.3.3 Habitat Characteristics
Gmelina forest had the highest average canopy cover (46.0 percent ± 6.1 S.E.) followed
by homegardens (27.6 percent ± 4.8) and shrub-land (9.0 percent ± 3.2) (Table 16.5).
The highest tree was also recorded for Gmelina forest (19.9 m ± 1.8), followed by
homegardens (16.5 m ± 1.9) and shrub-land (15.5 ± 1.2). The average tree density per
hectare for Gmelina forest (1,478.5 ± 278.2) was much higher than those recorded for
homegardens (575.5 ± 110.9) and shrub-land (466.7 ± 146.3) whereas the average
density of large trees (>20 cm dbh) did not differ much among the three habitat types
(345.0 ± 114.5 for Gmelina forest, 302.6 ± 80.1 for homegardens and 323.4 ± 108.1
for shrub-land). Ground cover was highest for Gmelina forest (68.5 percent ± 5.7) fol-
lowed by shrub-land (64.7 percent ± 5.4) and homegardens (54.3 percent ± 5). The
largest number of houses within 100 m of a point count or mist-net line centre was
recorded for shrub-land (6.2 ± 1.7) followed by homegardens (3.8 ± 0.9). Gmelina for-
est localities had on average the lowest number of houses (1.5 ± 0.5). However, none
of the differences in habitat characteristics between pairs of habitat types within a local-
ity was significant (non-parametric Wilcoxon signed rank test for related samples).
16.3.4
Average Bird and Bat Species Richness and Abundance
per Locality Per Habitat Type
The highest average numbers of resident bird species and forest bird species per
point count (Table 16.6) were recorded for Gmelina forest (5.43 ± 0.28 S.E. and
0.78 ± 0.19 respectively). Shrub-land had more resident bird species per point count
(4.25 ± 0.31) than homegardens (3.28 ± 0.27) but the average number of forest bird
species per point count was similar (0.25 ± 0.08 and 0.25 ± 0.09 for shrub-land and
homegardens respectively). The average number of resident bird individuals was
comparable for the three habitat types (9.54 ± 0.64 for Gmelina forest, 9.78 ± 1.10
for homegardens and 8.39 ± 0.79 for shrub-land). For forest birds, abundance was
higher in Gmelina forest (1.37 ± 0.32 individuals per point count) compared to
shrub-land (0.44 ± 0.18) and homegardens (0.33 ± 0.13).
The average number of bat species caught per mist-net-night was comparable for
the three habitat types (0.33 ± 0.07 for homegardens, 0.29 ± 0.05 for shrub-land and
0.24 ± 0.03 for Gmelina forest). The abundance of bats (average number of indi-
viduals caught per mist-net-night), however, was highest for homegardens (1.54 ±
0.49; for shrub-land: 0.93 ± 0.38; for Gmelina forest: 0.80 ± 0.11). Very few forest
bat species were caught, with the highest average species richness and abundance
per mist-net night recorded for homegardens (0.05 ± 0.04; 0.10 ± 0.07) followed by
shrub-land (0.03 ± 0.01; 0.04 ± 0.02) and Gmelina forest (0.01 ± 0.01; 0.01 ± 0.01).
The highest average numbers of cave bat species richness and abundance were
recorded for shrub-land (0.11 ± 0.03; 0.52 ± 0.39) and homegardens (0.10 ± 0.04;
0.44 ± 0.29). Gmelina forest had very few cave bats (0.04 ± 0.01; 0.10 ± 0.03).
Search WWH ::




Custom Search