Functional traits related to regeneration responses to the environment are highly determinants of distribution patterns of plant communities. A large body of studies on seed traits suggests that regional climate may act as a strong filter of plant recruitment; however, few studies have evaluated the relative importance of seed traits and environmental filters for seed persistence at the population level. We tested the role of seed mass, water content and desiccation tolerance, as well as the germination time as proxies for seed tolerance to environmental filters (water deficit, heat shock and high temperatures) by comparing the response of tree species co-occurring in savannas located in different regions: Cerrado biome of Central Brazil and the Rio Branco savannas of northern Brazil. Seeds collected in savannas of Rio Branco showed a higher tolerance to environmental filters than those collected in savannas of the Cerrado. While the germination percentages largely varied in response to the treatments, the germination times were virtually unaffected by them, irrespective of seed origin, seed mass and water content. At the population level, the regional environment was a key determinant of seed tolerance to stress, irrespective of seed traits. Germination time was shown to represent a conservative seed trait and more linked to a species-specific germination strategy than to regional characteristics. Our results suggest that recruitment patterns of Cerrado savannas may be more impacted than Rio Branco savannas by the climate scenarios predicted for the future.

This study explores how higher temperatures influence corn yield response to planting density. Using 1990–2010 field trial data from Wisconsin and econometric models with a variety of specifications, we find that higher temperatures reduce the yield benefits of increasing planting density. However, these adverse high-temperature effects are smaller for genetically modified corn varieties, especially those with rootworm-resistant traits. Consistent with previous studies, these results support the notion that varietal improvements through genetic modification may have paved the way for higher planting densities in US corn production. Moreover, our results imply that expected in-season temperatures are important considerations when making planting density decisions.

The food intake and growth rate of broilers kept at high temperatures can be improved by supplementing the diet or the drinking water with sodium bicarbonate. The response appears to be due to the bicarbonate ion and is associated with an increase in water consumption. Measurements of dietary or retained values for cation–anion balance or dietary electrolyte balance were unsatisfactory for predicting the growth and/or feed conversion responses of broilers at high temperatures. Improvements in body weight do not appear to be associated with increased body water retention.

Present-day organisms have colonised two distinct high pressure environments: the deep sea and oil well and other crustal fluids. In the former, pressures attain 100 MPa and temperatures are generally less than 4°C. In the latter, the temperatures are high, up to 150°C, and occur in combination with pressures of up to 50 MPa. The high temperature is close to the limit of thermal stability of the macromolecules essential for life. The adaptation of present-day marine organisms to high pressure is known to involve modifications to their cell membrane lipids and subtle changes in both structural proteins and enzymes. There is no reason to suppose that they are close to the maximum pressure to which they could adapt and higher pressures could have been colonised in the geological past. The existence of “marker” compounds, characteristic of high pressure organisms, is discussed, and the possibility that isotope ratios are distorted by metabolic processes at high pressure is raised.