The Brazilian Cerrado is becoming hotter and drier

Abstract

The Brazilian Cerrado is a global biodiversity hotspot with notoriously high rates of native vegetation suppression and wildfires over the past three decades. As a result, climate change can already be detected at both local and regional scales. In this study, we used three different approaches based on independent datasets to investigate possible changes in the daytime and nighttime temperature and air humidity between the peak of the dry season and the beginning of the rainy season in the Brazilian Cerrado. Additionally, we evaluated the tendency of dew point depression, considering it as a proxy to assess impacts on biodiversity. Monthly increases of 2.2−4.0℃ in the maximum temperatures and 2.4−2.8℃ in the minimum temperatures between 1961 and 2019 were recorded, supported by all analyzed datasets which included direct observations, remote sensing, and modeling data. The warming raised the vapor pressure deficit, and although we recorded an upward trend in absolute humidity, relative humidity has reduced by ~15%. If these tendencies are maintained, gradual air warming will make nightly cooling insufficient to reach the dew point in the early hours of the night. Therefore, it will progressively reduce both the amount and duration of nocturnal dewfall, which is the main source of water for numerous plants and animal species of the Brazilian Cerrado during the dry season. Through several examples, we hypothesize that these climate changes can have a high impact on biodiversity and potentially cause ecosystems to collapse. We emphasize that the effects of temperature and humidity on Cerrado ecosystems cannot be neglected and should be further explored from a land use perspective.

Bioclimatic zoning for dairy cows in Brazil by statistical modeling

“…Mutunópolis (GO), Poxoréo (MT), and Planalto da Serra (MT) had the lowest RH levels, with values of 30.46%, 32.11%, and 32.10% in the summer and 35.54%, 35.74%, and 35.73% in the winter, respectively. These results are consistent with Hofmann et al 53 …”

A novel in situ passive heating method for evaluating whole-tree responses to daytime warming in remote environments

“…However, AbsH remained largely unaffected by the WTHSs, suggesting that changes in RH and VPD were driven by changes in temperature and are an unavoidable consequence of temperature manipulation. Furthermore, RH has decreased over the Cerrado in recent years and could continue to fall with increasing temperatures [ 7 ], meaning our WTHSs may simulate more realistic climate change scenarios.…”

“…However, this important biome—like many significant non-forest woody ecosystems—has been historically undervalued and understudied [ 4 , 5 ], and is experiencing the highest rates of land use change in Brazil [ 6 ]. It is also under immediate threat from climate change [ 7 , 8 ], with regional climate models predicting a temperature increase of between 1 and 5 °C across the Cerrado biome by the end of this century [ 9 ]. Such increases in temperature have the potential to affect many aspects of plant growth and function [ 10 ], with repercussions for important plant–plant and plant–animal interactions [ 11 , 12 ], making it essential to improve our understanding of high temperature responses of native vegetation.…”

Taxonomic, functional, and phylogenetic diversity of lizard assemblages across habitats and seasons in a Brazilian Cerrado area

“…2019), mainly due to region's climate becoming increasingly hotter and drier, especially during the dry season months (Hofmann et al . 2021). Lizards can be negatively affected not only by the possible contraction of their activity periods (Piantoni et al .…”