The role of voles in agroecosystems: linking pest management to biodiversity conservation under environmental change
- ICETA - Instituto de Ciências e Tecnologias Agrárias e Agroalimentares(líder)
- Universidade de Évora(parceiro)
Summary
Agroecosystem services are being threatened worldwide by biodiversity loss. Biological pest management is one of the main ecosystem services often supported by agroecosystems, as non-crop habitats can provide resources for species that may act as natural controllers of agricultural pests, responsible for huge losses in crop yields. However, there is still limited understanding on how biodiversity levels relate with biological control, particularly considering current trends in agricultural land use change.
This project aims to assess the responses of rodents to agroecosystem structure and management practices, and evaluate how such responses may affect the potential for pest outbreaks. Rodents are key for overall ecosystem functioning, though they may also become crop pests associated to large damages in the agricultural sector. We will focus on the vole community of northeastern Portugal agroecosystems, which include both species of conservation concern and species considered as pests in many parts of the Iberian Peninsula, including our study region. Specifically we will study tree fruit orchards agroecosystems to test the predictions that: i) vole community composition reflects agroecosystem structure and intensity of management; ii) vole diversity and abundance correlates positively with plant diversity, which is higher in more heterogeneous and structurally complex agroecosystems, where pest outbreak risk is comparatively lower; iii) voles’ trophic niches vary according to the species, agricultural intensification levels, and seasons, with crops being relatively more consumed when/where overall plant diversity is lower; iv) despite some interspecific overlap in voles’ diets, trophic-niche partitioning should occur among coexisting species, particularly when resources are limited; v) the relative importance of “bottom-up” regulation and biotic interactions for pest management changes according to agroecosystem structure and management practices.
Overall, we expect this project to provide a greater understanding on how agroecosystem functioning and services may be affected by environmental change, thus contributing for improving their management and conservation.
Goals, activities and expected/achieved results
Goals
In this project, we intend to evaluate the potential of voles as bioindicators of agroecosystem health and long-term sustainability. We will assess the responses of vole communities to agricultural intensification, considering the effects of different population processes, namely, “bottom-up” regulation (through changes in plant communities), and biotic relations (e.g. interspecific competition). We also intend to evaluate how such responses may influence the potential for pest outbreaks or impact the resilience of vole species of conservation concern. Focusing on tree-fruit orchard agroecosystems in northeastern Portugal, we have defined the following objectives:
1. Assess how the diversity and abundance of voles vary according to the agroecosystem structure and intensification levels;
2. Evaluate how overall plant diversity varies locally across intensification levels and how it affects vole species occupancy and abundance – “bottom-up” regulation;
3. Estimate the trophic niche breadth and overlap of co-occurring voles, across seasons and intensification levels, through DNA metabarcoding of faecal pellets;
4. Assess the importance of crops species in voles’ diets, and how their diets shift according to differences in crop and plant diversity and abundance;
5. Estimate the importance of current agricultural management practices and biotic interactions within vole communities, on crop damage regulation and the conservation of vulnerable vole species;
Activities
We will use a multidisciplinary approach, combining ecological tools and high throughput molecular methods to address our objectives.
At a landscape scale, we will analyse on voles’ distribution in the NE Portugal, together with spatial information on agroecosystem composition and structure, level of agricultural intensification, and damage records, to assess the spatial distribution patterns of the vole community.
We will then use the collected information to select fruit tree orchards of variable sizes and management regimes, that include both pest and non-pest vole species, for the local scale study. At each selected parcel, detailed plant and vole surveys will be conducted, combining ecological techniques with molecular methods. Plant diversity will be estimated through traditional vegetation surveys, and non-invasive methods will be used for assessing vole occupancy and abundance. Tree damage by voles will also be assessed on each focal orchard. The voles trophic niche and food availability, will be estimated using high-throughput sequencing techniques, namely DNA metabarcoding.
Data analyses will focus on integrating the results of the ecological assessments and molecular methods for assessing the factors influencing vole community diversity and abundance across a gradient of agricultural intensification. These analyses will allow us to gain information on the responses of vole communities to agroecosystem structure and management practices, namely considering population regulatory processes as “bottom-up” effects and biotic interactions.
Results
This project is expected to make a significant contribution to understand how agroecosystem structure and management affects voles’ populations regulatory processes, and how the differential responses of voles’ communities may impact the economic viability of agroecosystems (e.g. through pest outbreaks). We also expect to clarify how these responses will influence the resilience of the species of conservation concern.
Overall, we expect voles to be good bioindicators of ecosystem health, with higher pest outbreak risks being linked to lower plant diversities and unbalanced vole abundances. Different vole species are expected to show some degree of trophic niches partitioning, particularly when/where resources are limited, despite of some possible overlap in diets. Crops are also expected to be more consumed if overall plant diversity is lower, as may be the case in highly managed areas. Therefore, by fostering plant diversity and more diverse voles’ communities, traditional agricultural practices should contribute to reduce the risk of pest outbreaks. Also, by increasing our knowledge on voles’ community dynamics, and our ability to predict their responses to environmental change, we should be able to forecast situations of high pest outbreak risk.
| Attribute | Type | Value |
|---|---|---|
| id | integer | 3870 |
