Corresponding author: Alejandro Muñoz-Urias (
Academic editor: J. Neff
Bee communities were studied with three different conditions of land-use: 1) urban area; 2) crops and livestock; and, 3) preserved vegetation. All three conditions have elements of tropical dry forest and are in the "Sierra de Quila" Flora and Fauna Protection Area and its influence zone. Sampling was carried out throughout the year (three days per month) for each land-use condition. Bee species and their abundance were registered with the intention of knowing how changes in the vegetation are related to bee community structure (richness, abundance, and α and β diversity).
A total of 14,054 individuals from 160 species were registered. A rarefaction analysis, showed that the preserved areas had significantly greater richness and diversity. Beta diversity analysis revealed a species turnover of nearly 32% among each pair of conditions. It is concluded that the changes in land-use negatively affect richness and diversity and causes major changes in species composition of the bee community. For this reason, it is recommended that the protection of the tropical dry forest, both for this study area but also in general for Mexico, is essential to guarantee the conservation of this group of insects, which are required for the reproduction of a great number wild and cultivated plant specie.
Razo-León AE, Vásquez-Bolaños M, Muñoz-Urias A, Huerta-Martínez FM (2018) Changes in bee community structure (Hymenoptera, Apoidea) under three different land-use conditions. Title. Journal of Hymenoptera Research 66: 23–38.
Pollinators are a key component for global biodiversity, because they assist in the sexual reproduction of many plant species and play a crucial role in maintaining terrestrial ecosystems and food security for human beings (
Tropical dry forest present a great bee species richness in Mexico (
Land use change, such as degradation or fragmentation of tropical dry forest, could have consequences on the richness and composition of bee communities. According to previous studies, bees are susceptible to the loss of their natural habitats by the fragmentation and transformation of the landscape for agricultural, livestock and urban purposes (
Two of the most important factors for bee communities are food availability (nectar and pollen) and nesting sites (
The study is located at Área de protección de flora y fauna Sierra de Quila, (here and after
Location of the
Three conditions in tropical dry forest (
Sampling of wild bees was conducted throughout the year, with three sampling days per month (one working day per condition, from 10:00 to 16:00 hours). Four plots, 50 × 5 m, were randomly located for each land use condition and the bees were sample walking along the transect during periods of 60 minutes per collection. Bee species presences and their abundance were recorded. Bee species that could not be determined in the field were collected using an entomological net with extension of 2.70 m on tree strata and an extension of 1.00 m for herbaceous strata. Specimens were processed according to
A species accumulation curve was performed to evaluate the sampling effort per site and, as well as to compare the richness among the different conditions using ESTIMATES 9.1.0. (
Bee abundances with and without
The Shannon-Wiener index was used to compare alpha diversity of sites via a confidence interval obtained using bootstrap in PAST 3.15 software (
A total of 14,054 bees individuals were registered, belonging to five families, 52 genera, and 160 species (Table
Richness and abundance of the bee families registered.
Family | Genera | Species | Abundance |
---|---|---|---|
|
23 | 60 | 12,170 |
|
8 | 33 | 759 |
|
13 | 35 | 739 |
|
5 | 20 | 214 |
|
3 | 12 | 172 |
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|
|
|
The richest condition was P, with 120 species, followed by
Rarefaction curve for bee richness among the different land-use conditions.
The highest number of bee individuals was observed in P (5,067), followed by
Pearson’s chi-squared test showed a dependency between land-use and bee family abundance (df = 8, χ 2 = 560.2715,
Abundance per bee family in different conditions of land-use. Abundance of
Family | U |
|
P |
---|---|---|---|
|
3,545 (1,748) | 4,345 (1,434) | 4,279 (1,943) |
|
427 | 141 | 192 |
|
168 | 259 | 313 |
|
57 | 24 | 133 |
|
5 | 17 | 150 |
Residual analysis with Pearson’s chi-squared test to compare independence between bee family and land use conditions.
The Shannon-Wiener index (H') values presented significant differences with a
Shannon-Wiener diversity index (H') per land-use condition and their confidence intervals (IC 95%) via bootstrap, and maximum diversity (H'max), Evenness (J'), including
H' | -CI 95% | +CI 95% | H'max | J' | |
---|---|---|---|---|---|
Including |
|||||
U | 2.605b | 2.561 | 2.666 | 4.40 | 0.591 |
|
1.933c | 1.889 | 2.00 | 4.58 | 0.421 |
P | 2.755ª | 2.703 | 2.813 | 4.79 | 0.574 |
Excluding |
|||||
U | 3.342b | 3.313 | 3.403 | 4.39 | 0.760 |
|
3.225b | 3.187 | 3.319 | 4.57 | 0.704 |
P | 3.830a | 3.790 | 3.878 | 4.78 | 0.800 |
Measurements with the same letter do not differ statistically, according to the confidence intervals.
The beta diversity index (βsim) showed an average species turnover rate of about 32% for each condition. In terms of bee species composition change, the highest was between U and
The indirect ordination performed with NMDS resulted in a stress value of 0.1326, that shows a gradual separation of the three different land-use conditions along the first axis, where on the left side are located U sites,
Ordination diagram derived from NMDS for the different land-use areas and bee tribal data.
The highest bee richness was registered in P while the only significant differences were recorded between U and P. The results indicate a gradient in richness related to the habitat conservation. This finding is supported by different studies which show that the destruction of the habitat, for agriculture or urbanization, is principally responsible for bee species reduction, up to the point of local extinction for some species (
The decrease in bee richness is related to their dependence on various resources to complete their lifecycle, such as food resources (pollen and nectar) and nesting substrates (either from the soil or vegetation), and materials for constructing their nests (
The abundance of bees did not differ significantly between the three land-use conditions. This agrees with various studies that report a similar or greater abundance in human modified areas (
The number of individuals per family varied,
Total bee abundance tends to decline at disturbed sites, while individual species present different responses, some of them show drastic reduction in their populations, while others remain stable or even increase with land-use change (
Finally, β diversity showed a medium level of species turnover rate among conditions, despite the maximum distance between sampling sites was 6 km. The structure of bee community contrasts with P and U, in which tribes such as
The bee fauna of the
The
We thank anonymous reviewers for suggesting improvements to the manuscript. A doctoral scholarship from CONACYT, Hugo Eduardo Fierros-López (CUCBA, University of Guadalajara) for the identification of bees, Regional Committee for the Protection and Promotion of the Natural Resources of the Sierra de Quila A.C. for all its institutional and logistical support, Raymundo Villavicencio and Victoria Belen Muñoz for the preparation of the map.
Number of individuals per bee species registered in different land use conditions.
|
|
|
|
20 | 6 | 21 | |
9 | 0 | 1 | |
35 | 2 | 8 | |
0 | 0 | 25 | |
0 | 0 | 12 | |
0 | 0 | 1 | |
0 | 1 | 0 | |
1 | 13 | 42 | |
0 | 0 | 2 | |
0 | 0 | 8 | |
0 | 0 | 1 | |
0 | 4 | 7 | |
0 | 0 | 1 | |
160 | 39 | 0 | |
0 | 31 | 26 | |
178 | 2910 | 2336 | |
0 | 29 | 0 | |
0 | 0 | 1 | |
42 | 0 | 0 | |
6 | 17 | 28 | |
9 | 6 | 4 | |
13 | 11 | 12 | |
29 | 2 | 34 | |
37 | 0 | 0 | |
0 | 0 | 2 | |
25 | 28 | 3 | |
4 | 1 | 0 | |
30 | 11 | 39 | |
0 | 0 | 2 | |
0 | 1 | 3 | |
0 | 1 | 9 | |
0 | 2 | 0 | |
1 | 0 | 0 | |
0 | 0 | 1 | |
0 | 0 | 3 | |
0 | 6 | 0 | |
0 | 1 | 4 | |
0 | 4 | 0 | |
37 | 30 | 68 | |
125 | 14 | 3 | |
18 | 0 | 0 | |
1 | 3 | 5 | |
1 | 1 | 6 | |
3 | 0 | 7 | |
1 | 47 | 42 | |
20 | 9 | 12 | |
20 | 5 | 10 | |
7 | 0 | 0 | |
1 | 1 | 1 | |
0 | 1 | 0 | |
0 | 1 | 0 | |
0 | 0 | 16 | |
0 | 0 | 42 | |
1 | 1 | 5 | |
0 | 0 | 1 | |
0 | 0 | 1 | |
0 | 0 | 8 | |
56 | 159 | 5 | |
0 | 1 | 0 | |
0 | 70 | 20 | |
0 | 1 | 10 | |
0 | 1 | 0 | |
6 | 0 | 0 | |
0 | 0 | 3 | |
76 | 8 | 66 | |
6 | 0 | 11 | |
0 | 1 | 0 | |
51 | 25 | 2 | |
0 | 21 | 33 | |
26 | 2 | 3 | |
8 | 0 | 7 | |
0 | 0 | 4 | |
122 | 320 | 87 | |
113 | 0 | 3 | |
0 | 0 | 1 | |
0 | 6 | 20 | |
2 | 5 | 26 | |
1 | 4 | 0 | |
0 | 0 | 4 | |
1 | 0 | 0 | |
0 | 0 | 4 | |
0 | 0 | 1 | |
1 | 0 | 11 | |
1 | 0 | 0 | |
0 | 3 | 0 | |
0 | 3 | 0 | |
2 | 0 | 2 | |
0 | 18 | 2 | |
0 | 4 | 0 | |
0 | 0 | 5 | |
1 | 3 | 0 | |
0 | 2 | 4 | |
0 | 0 | 5 | |
1 | 0 | 6 | |
3 | 16 | 3 | |
0 | 0 | 3 | |
9 | 0 | 0 | |
2 | 1 | 1 | |
4 | 1 | 0 | |
0 | 0 | 1 | |
0 | 52 | 5 | |
13 | 0 | 8 | |
2 | 5 | 2 | |
38 | 0 | 11 | |
2 | 1 | 14 | |
0 | 17 | 10 | |
23 | 13 | 62 | |
69 | 0 | 0 | |
2 | 1 | 2 | |
5 | 4 | 9 | |
8 | 36 | 4 | |
0 | 0 | 1 | |
1 | 0 | 0 | |
0 | 1 | 16 | |
46 | 18 | 8 | |
0 | 1 | 0 | |
3 | 6 | 7 | |
20 | 12 | 12 | |
0 | 2 | 0 | |
1 | 28 | 7 | |
70 | 1 | 49 | |
0 | 5 | 0 | |
0 | 0 | 3 | |
0 | 7 | 43 | |
0 | 2 | 14 | |
3 | 0 | 54 | |
0 | 4 | 9 | |
439 | 84 | 245 | |
125 | 49 | 1 | |
1 | 0 | 0 | |
0 | 2 | 20 | |
0 | 0 | 145 | |
12 | 1 | 41 | |
37 | 0 | 16 | |
0 | 11 | 0 | |
3 | 3 | 0 | |
0 | 0 | 2 | |
1 | 0 | 0 | |
66 | 6 | 2 | |
1 | 1 | 14 | |
0 | 2 | 0 | |
1 | 0 | 0 | |
0 | 0 | 1 | |
1 | 1 | 0 | |
134 | 388 | 196 | |
0 | 0 | 1 | |
0 | 2 | 1 | |
0 | 6 | 19 | |
5 | 14 | 22 | |
0 | 2 | 32 | |
0 | 23 | 8 | |
0 | 1 | 38 | |
2 | 0 | 25 | |
0 | 14 | 172 | |
1 | 0 | 0 | |
0 | 1 | 214 | |
134 | 43 | 124 | |
1 | 1 | 53 | |
0 | 0 | 108 | |
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