Ecological determinants of American crow mortality due to West Nile virus during its North American sweepOecologia - Tập 163 - Trang 903-909 - 2010
Walter D. Koenig, Wesley M. Hochachka, Benjamin Zuckerberg, Janis L. Dickinson
We examined the ecological factors influencing population declines in American crows (Corvus brachyrhynchos) as they were initially exposed to West Nile virus (WNV), a pathogen first detected in the US in 1999 that has since become one of North America’s most prevalent vector-borne pathogens. The strongest effects were initial crow population density (denser populations were more likely to suffer ...... hiện toàn bộ
The evolution of crassulacean acid metabolism inAeonium inferred from carbon isotope composition and enzyme activitiesOecologia - Tập 91 - Trang 548-553 - 1992
E. A. H. Pilon-Smits, H. 't Hart, J. W. Maas, J. A. N. Meesterburrie, R. Kreuler, J. van Brederode
Variation in crassulacean acid metabolism (CAM) was investigated in thirtyAeonium species under controlled, well-watered conditions. Carbon isotope ratios and the specific activities of the CAM enzymes phosphoenolpyruvate carboxylase (PEPC) and malic enzyme ME_ are highly correlated and indicate a large variation in CAM. The δ13C values range from -13.6 to -27.1‰; PEPC and ME activities vary seven...... hiện toàn bộ
Generalist birds govern the seed dispersal of a parasitic plant with strong recruitment constraintsOecologia - Tập 176 - Trang 139-147 - 2014
Ana Mellado, Regino Zamora
Mistletoes constitute instructive study cases with which to address the role of generalist consumers in the study of plant–animal interactions. Their ranges of safe sites for recruitment are among the most restricted of any plant; therefore, frugivores specializing in mistletoe have been considered almost indispensable for the seed dispersal of these parasitic plants. However, the absence of such ...... hiện toàn bộ
Ecophysiological studies on the shrub Vaccinium myrtillus L. taken from a wide altitudinal rangeOecologia - Tập 70 - Trang 580-586 - 1986
F. I. Woodward
Observations have been made on the gas exchange and morphology of Vaccinium myrtillus taken from altitudes of 200 m, 610 m and 1,100 m along an altitudinal gradient in central Scotland. Under saturating irradiance, optimum temperatures and a range of vapour pressure deficits, photosynthetic rate and stomatal conductance increased with the altitude of origin of the populations. Correlated with thes...... hiện toàn bộ
Individual and interactive effects of chronic anthropogenic disturbance and rainfall on taxonomic, functional and phylogenetic composition and diversity of extrafloral nectary-bearing plants in Brazilian CaatingaOecologia - Tập 198 - Trang 267-277 - 2021
Xavier Arnan, Carlos H. F. Silva, Daniela Q. A. Reis, Fernanda M. P. Oliveira, Talita Câmara, Elâine M. S. Ribeiro, Alan N. Andersen, Inara R. Leal
Chronic anthropogenic disturbance (CAD) and climate change represent two of the major threats to biodiversity globally, but their combined effects are not well understood. Here we investigate the individual and interactive effects of increasing CAD and decreasing rainfall on the composition and taxonomic (TD), functional (FD) and phylogenetic diversity (PD) of plants possessing extrafloral nectari...... hiện toàn bộ
Flowering phenology in the central highland of Iceland and implications for climatic warming in the ArcticOecologia - Tập 114 - Trang 43-49 - 1998
Thóra Ellen Thórhallsdóttir
The cool and short growing season that characterizes Arctic climates puts severe constraints on life cycles and reproduction in the Arctic flora. The timing of flowering is particularly critical and may affect both breeding system and reproductive success through the heavy penalties associated with later flowering. An 11-year study of 75 species in the central highland of Iceland showed that the ...... hiện toàn bộ