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Projeto de investigação
Modelling the impact of changing agricultural policies on biodiversity and ecosystem services
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Publicações
Canopy arthropod declines along a gradient of olive farming intensification
Publication . Vasconcelos, Sasha; Pina, Silvia; Herrera, José M.; Silva, Bruno; Sousa, Pedro; Porto, Miguel; Melguizo-Ruiz, Nereida; Jimenez-Navarro, Gerardo; Ferreira, Sónia; Moreira, Francisco; Heleno, Ruben; Jonsson, Mattias; Beja, Pedro
Arthropod declines have been linked to agricultural intensification. However, information about the
impacts of intensification is still limited for many crops, as is our understanding of the responses
of different arthropod taxa and trophic groups, thus hindering the development of effective
mitigation measures. We investigated the impacts of olive farming intensification on canopydwelling
arthropods in the Mediterranean region. Intensification involves the increased use of
agrochemicals, mechanisation and irrigation, but also structural changes from traditional orchards
with low densities of large and old trees, to intensive and superintensive orchards with high to
very high densities of smaller and younger trees, respectively. Canopy arthropods were vacuumsampled
at 53 sites representing the three orchard intensification levels, in spring, summer and
autumn 2017. We evaluated how the arthropod community varied across intensification levels, and
in response to orchard structure, management and landscape context. We found no changes in the
diversity of arthropod taxa across intensification levels after correcting for sample coverage, but
arthropod abundance declined markedly along the intensification gradient. Decreased abundance
was associated with changes in orchard structure, lower herbaceous cover, and higher herbicide
and insecticide use. The abundance of a specialized olive pest was lower in landscapes with higher
woodland cover. The negative effects of intensification were stronger in spring and summer than
in autumn, and parasitoids and predators were particularly affected. Overall, results suggest that
retaining herbaceous cover, reducing agrochemical inputs and preserving natural woody elements
in the landscape, may contribute to mitigate impacts of olive farming intensification on canopy
arthropods, particularly on beneficial species
Fitness, behavioral, and energetic trade-offs of different migratory strategies in a partially migratory species
Publication . Soriano-Redondo, Andrea; Franco, Aldina M. A.; Acácio, Marta; Payo-Payo, Ana; Martins, Bruno Herlander; Moreira, Francisco; Catry, Inês
Alternative migratory strategies can coexist within animal populations and
species. Anthropogenic impacts can shift the fitness balance between these
strategies leading to changes in migratory behaviors. Yet some of the mecha-
nisms that drive such changes remain poorly understood. Here we investigate
the phenotypic differences, and the energetic, behavioral, and fitness trade-offs
associated with four different movement strategies (long-distance and
short-distance migration, and regional and local residency) in a population of
white storks (Ciconia ciconia) that has shifted its migratory behavior over the
last decades, from fully long-distance migration toward year-round residency.
To do this, we tracked 75 adult storks fitted with GPS/GSM loggers with
tri-axial acceleration sensors over 5 years, and estimated individual displace-
ment, behavior, and overall dynamic body acceleration, a proxy for
activity-related energy expenditure. Additionally, we monitored nesting colo-
nies to assess individual survival and breeding success. We found that
long-distance migrants traveled thousands of kilometers more throughout the
year, spent more energy, and >10% less time resting compared with
short-distance migrants and residents. Long-distance migrants also spent on average more energy per unit of time while foraging, and less energy per unit
of time while soaring. Migratory individuals also occupied their nests later
than resident ones, later occupation led to later laying dates and a lower num-
ber of fledglings. However, we did not find significant differences in survival
probability. Finally, we found phenotypic differences in the migratory proba-
bility, as smaller sized individuals were more likely to migrate, and they might
be incurring higher energetic and fitness costs than larger ones. Our results
shed light on the shifting migratory strategies in a partially migratory popula-
tion and highlight the nuances of anthropogenic impacts on species behavior,
fitness, and evolutionary dynamics.
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Entidade financiadora
Fundação para a Ciência e a Tecnologia
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Investigador FCT
Número da atribuição
IF/01053/2015/CP1278/CT0001