The consequences of climate change for dryland biogeochemistry

Abstract

Summary Drylands, which cover > 40% of Earth's terrestrial surface, are dominant drivers of global biogeochemical cycling and home to more than one third of the global human population. Climate projections predict warming, drought frequency and severity, and evaporative demand will increase in drylands at faster rates than global means. As a consequence of extreme temperatures and high biological dependency on limited water availability, drylands are predicted to be exceptionally sensitive to climate change and, indeed, significant climate impacts are already being observed. However, our understanding and ability to forecast climate change effects on dryland biogeochemistry and ecosystem functions lag behind many mesic systems. To improve our capacity to forecast ecosystem change, we propose focusing on the controls and consequences of two key characteristics affecting dryland biogeochemistry: (1) high spatial and temporal heterogeneity in environmental conditions and (2) generalized resource scarcity. In addition to climate change, drylands are experiencing accelerating land‐use change. Building our understanding of dryland biogeochemistry in both intact and disturbed systems will better equip us to address the interacting effects of climate change and landscape degradation. Responding to these challenges will require a diverse, globally distributed and interdisciplinary community of dryland experts united towards better understanding these vast and important ecosystems.

Effects of experimental nitrogen deposition on soil organic carbon storage in Southern California drylands

“…Drylands make up ~45% of the global land area and store up to 33% of the global SOC stocks contained in the top 1 m of soil (Plaza, Zaccone, et al, 2018; Prăvălie, 2016). Therefore, dryland response to N deposition could have substantial consequences on global C cycling and soil quality (Homyak et al, 2014; Osborne et al, 2022; Plaza, Gascó, et al, 2018), but they are underrepresented in global analyses evaluating N fertilization effects on soil C storage (Xu et al, 2021). While both increases and decreases in SOC have been measured along N deposition gradients in drylands (Maestre et al, 2016; Ochoa‐hueso et al, 2013), the magnitude of and mechanisms behind dryland C storage change in response to N deposition remain unclear.…”

Response of soil carbon dioxide efflux to temporal repackaging of rainfall into fewer, larger events in a semiarid grassland

“…Dryland ecosystems have high spatial heterogeneity in soil properties and vegetation distribution, which presents challenges for understanding ecosystem responses to changes in climate, including rainfall size and frequency (Osborne et al, 2022). Because we observed large variability in seasonal total F s for the many/small regime (Table 2), future research should examine how spatial heterogeneity and colimitation of multiple resources (e.g., water, carbon, nutrients) mediate carbon cycling responses to rainfall repackaging (Choi et al, 2022;Osborne et al, 2022). There is also a Frontiers in Environmental Science frontiersin.org need to better understand how soil texture shapes F s responses to rainfall repackaging.…”

Restoration research actions to address rapid change in drylands: insights from the Colorado Plateau

“…pine mulch and pits to increase seed and water retention) can enhance seedling recruitment across sites, but that recruitment is also strongly linked to the environmental context of restoration, namely precipitation patterns (Havrilla et al 2020). Coordinated research efforts, such as these, represent ways to provide information across sites to support effective restoration action (Osborne et al 2022a).…”