| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 2.68 MB | Adobe PDF |
Advisor(s)
Abstract(s)
Assessing the spatio-temporal impact of agricultural intensification on species and communities is key for
biodiversity conservation. Here, we investigated the seasonal effects of olive grove intensification at both local
(farming practices and grove structural complexity) and landscape scale (land-cover diversity) on birds and bats,
at species and community-level. Both groups were surveyed during spring, summer, and autumn in 60 sites
representing varying levels of olive grove intensification throughout the Alentejo region (southern Portugal). At
the local scale, the number of chemical applications was used as a proxy for the intensification of farming
practices and a Structural Index, which accounted for within-grove variability in tree density and features, was
used as a measure of grove structural complexity. At landscape scale, we quantified the proportion of the major
land-cover types potentially affecting birds and bats. We found that the abundance of ca. 77% of the species
analyzed (ca. 84% and 55% of birds and bats respectively) was negatively related to olive grove intensification in
at least one season. The Structural Index was the most influential factor at both species and community-levels,
especially for birds, with a consistent and strong effect across seasons. Chemical applications had a stronger
negative effect on birds, whereas the amount of olive grove cover had a stronger detrimental effect on bats. Birds
and bats showed a variable response to predictor variables depending on the season, particularly for the bat
community. Our study shows differences in bird and bat responses associated with the spatio-temporal variability
of the agricultural intensification components. On the one hand, birds and bats showed a seasonal pattern of
association with the different components of olive grove intensification, probably due to their ecological and
biological requirements. On the other hand, the responses of both groups also appear to be scale-dependent:
while birds seem to respond to in-farm or local intensification more strongly, bats seem to be more influenced
by landscape-scale simplification. Overall, we highlight the importance of the structural complexity of olive
groves for birds and bats, an aspect that should be considered in the design of agricultural policies aiming to
promote biodiversity conservation.
Description
Keywords
agricultural intensification olive groves birds and bats grove structural complexity biodiversity conservation in agroecosystems
Pedagogical Context
Citation
Alvarenga, Paula, et al. “Evaluation of the Fertilizer Potential of Chlorella Vulgaris and Scenedesmus Obliquus Grown in Agricultural Drainage Water from Maize Fields.” Science of The Total Environment, vol. 861, Feb. 2023, p. 160670.
Publisher
Elsevier