نتایج جستجو برای: latitude
تعداد نتایج: 16503 فیلتر نتایج به سال:
Wood density is an important trait in trees indicative of their life history and mechanical and physiological strategies. The following examines the evolutionary ecology of wood density using a large database for seed plants. In particular, we focused on the geographic and phylogenetic variation in wood density for both gymnosperms and angiosperms. A phylogenetic supertree was constructed for o...
Paliurus favonii Unger is recognized and described based on fruits from the Oligocene Ningming flora of Guangxi, South China. Characteristics of the present specimens include circular winged fruits that are 10.0-11.5 mm in diameter with a central endocarp at 3.0 to 4.0 mm in diameter. The specimens fall into the morphological range of the fossil species P. favonii, which has been observed in ot...
Situated adjacent to the largest Northern Hemispher ice sheets of the ice ages, the mid-latitude North Atlantic Ocean has an important role in the earth's climate history. It provides a significant local source of moisture for the atmosphere and adjacent continents, forms a corridor that guides moisture-bearing storms northward from low latitudes, and at times makes direct contact along its sho...
Seasonal changes in ovulatory activity, assessed by the measurement of plasma progesterone and plasma prolactin concentrations were monitored in 10 Spanish ibex females captured in the National Wildlife Reserve of Sierra Nevada (South Spain, 37 degrees N). Five of the 10 female ibex showed ovulatory activity with a mean (+/- s.e.m.) duration of the oestrous cycle of 19.4 +/- 1 days (range: 17-2...
Temperature and salinity data from 2001 through 2005 from Argo profiling floats have been analyzed to examine the time evolution of the mixed layer depth (MLD) and density in the late fall to early spring in mid to high latitudes of the North Pacific. To examine MLD variations on various time scales from several days to seasonal, relatively small criteria (0.03 kg m–3 in density and 0.2°C in te...
The latitudinal gradient of species richness has frequently been attributed to higher diversification rates of tropical groups. In order to test this hypothesis for mammals, we used a set of 232 genera taken from a mammalian supertree and, additionally, we reconstructed dated Bayesian phylogenetic trees of 100 genera. For each genus, diversification rate was estimated taking incomplete species ...
Latitudinal gradients in population dynamics can arise through regional variation in the deterministic components of the population dynamics and the stochastic factors. Here, we demonstrate an increase with latitude in the contribution of a large-scale climate pattern, the North Atlantic Oscillation (NAO), to the fluctuations in size of populations of two European hole-nesting passerine species...
European forests host a diversity of tree species that are increasingly threatened by fungal pathogens, which may have cascading consequences for forest ecosystems and their functioning. Previous experimental studies suggest that foliar and root pathogen abundance and disease severity decrease with increasing tree species diversity, but evidences from natural forests are rare. Here, we tested w...
Life history traits in many ectotherms show complex patterns of variation among conspecific populations sampled along wide latitudinal or climatic gradients. However, few studies have assessed whether these patterns can be explained better by thermal reaction norms of multiple life history traits, covering major aspects of the life cycle. In this study, we compared five populations of a Holarct...
Many studies show that seagrass δ(15)N ratios increase with the amount of urbanization in coastal watersheds. However, there is little information on the relationship between urbanization and seagrass δ(15)N ratios on a global scale. We performed a meta-analysis on seagrass samples from 79 independent locations to test if seagrass δ(15)N ratios correlate with patterns of population density and ...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید