Divergent forest sensitivity to repeated extreme droughts

Anderegg, William R. L.; Trugman, Anna T.; Badgley, Grayson; Konings, Alexandra G.; Shaw, John D.

doi:10.1038/s41558-020-00919-1

Cited by 216 publications

(162 citation statements)

References 68 publications

Supporting

Mentioning

129

Contrasting

Unclassified

Order By: Relevance

“…Press events result in moderate drought stress for months or even years, with lower than normal precipitation, but with brief moments of recovery. Since both drought types affect plant communities and ecosystem resistance in different ways, this distinction may be of particular importance when ecosystems are subjected to multiple extremes (Anderegg et al, 2020). High predictability of plant mortality by the time spent below PWP (Figure 6b,c), suggests that the period during which pulse droughts occur is the main determinant of their outcome (e.g., drought during summer and/or heatwaves resulted in longer periods below PWP and higher end‐of‐season mortality).…”

Section: Discussionmentioning

confidence: 99%

Risk of short‐term biodiversity loss under more persistent precipitation regimes

Reynaert

Boeck

Verbruggen

et al. 2021

Global Change Biology

View full text Add to dashboard Cite

Recent findings indicate that atmospheric warming increases the persistence of weather patterns in the mid‐latitudes, resulting in sequences of longer dry and wet periods compared to historic averages. The alternation of progressively longer dry and wet extremes could increasingly select for species with a broad environmental tolerance. As a consequence, biodiversity may decline. Here we explore the relationship between the persistence of summer precipitation regimes and plant diversity by subjecting experimental grassland mesocosms to a gradient of dry–wet alternation frequencies whilst keeping the total precipitation constant. The gradient varied the duration of consecutive wet and dry periods, from 1 up to 60 days with or without precipitation, over a total of 120 days. An alternation of longer dry and wet spells led to a severe loss of species richness (up to –75% relative to the current rainfall pattern in W‐Europe) and functional diversity (enhanced dominance of grasses relative to nitrogen (N)‐fixers and non‐N‐fixing forbs). Loss of N‐fixers and non‐N‐fixing forbs in severe treatments was linked to lower baseline competitive success and higher physiological sensitivity to changes in soil moisture compared to grasses. The extent of diversity losses also strongly depended on the timing of the dry and wet periods. Regimes in which long droughts (≥20 days) coincided with above‐average temperatures showed significantly more physiological plant stress over the experimental period, greater plant mortality, and impoverished communities by the end of the season. Across all regimes, the duration of the longest period below permanent wilting point was an accurate predictor of mortality across the communities, indicating that increasingly persistent precipitation regimes may reduce opportunities for drought stress alleviation. We conclude that without recruitment, which was precluded in this experiment, summer precipitation regimes with longer dry and wet spells will likely diminish plant diversity, at least in the short term.

show abstract

Section: Discussionmentioning

confidence: 99%

Risk of short‐term biodiversity loss under more persistent precipitation regimes

Reynaert

Boeck

Verbruggen

et al. 2021

Global Change Biology

View full text Add to dashboard Cite

show abstract

“…Our results and those of others (e.g. Duan et al ., 2018; Anderegg et al ., 2020) suggest that future droughts may favour the dominance of xeric (e.g. E. populnea ) over mesic species (e.g.…”

Section: Discussionmentioning

confidence: 99%

Drought by CO₂interactions in trees: a test of the water savings mechanism

et al. 2021

View full text Add to dashboard Cite

Summary Elevated atmospheric CO2 (eCa) may benefit plants during drought by reducing stomatal conductance (gs) but any ‘water savings effect’ could be neutralized by concurrent stimulation of leaf area. We investigated whether eCa enhanced water savings, thereby ameliorating the impact of drought on carbon and water relations in trees. We report leaf‐level gas exchange and whole‐plant and soil water relations during a short‐term dry‐down in two Eucalyptus species with contrasting drought tolerance. Plants had previously been established for 9 to 11 months in steady‐state conditions of ambient atmospheric CO2 (aCa) and eCa, with half of each treatment group exposed to sustained drought for 5 to 7 months. The lower stomatal conductance under eCa did not lead to soil moisture savings during the dry‐down due to the counteractive effect of increased whole‐plant leaf area. Nonetheless, eCa‐grown plants maintained higher photosynthetic rates and leaf water potentials, making them less stressed during the dry‐down, despite being larger. These effects were more pronounced in the xeric species than the mesic species, and in previously water‐stressed plants. Our findings indicate that eCa may enhance plant performance during drought despite a lack of soil water savings, especially in species with more conservative growth and water‐use strategies.

show abstract

“…For example, if drought‐induced depletion of nonstructural carbohydrates or losses in leaf area via crown dieback have occurred, post‐drought allocation of carbohydrate reserves or assimilates toward structural recovery, such as xylem regrowth, may be insufficient (Trugman et al, 2018), which is consistent with widespread, incomplete drought recovery (Anderegg, Schwalm, et al, 2015). Yet, even if NPP does manage to recover, these legacies of previous droughts may increase mortality vulnerability to subsequent droughts, as was recently shown to be widespread in forests (Anderegg et al, 2020). Other work leveraging observational PPT–ANPP datasets in grasslands has also shown that the strength of such lags, and thus the influence of previous‐year conditions, may increase with the duration of multi‐year PPT anomalies (Petrie et al, 2018).…”

Section: A Role For the Duration Of Precipitation Anomaliesmentioning

confidence: 99%

Precipitation–productivity relationships and the duration of precipitation anomalies: An underappreciated dimension of climate change

Felton

Knapp

Smith

2020

Global Change Biology

View full text Add to dashboard Cite

In terrestrial ecosystems, climate change forecasts of increased frequencies and magnitudes of wet and dry precipitation anomalies are expected to shift precipitation–net primary productivity (PPT–NPP) relationships from linear to nonlinear. Less understood, however, is how future changes in the duration of PPT anomalies will alter PPT–NPP relationships. A review of the literature shows strong potential for the duration of wet and dry PPT anomalies to impact NPP and to interact with the magnitude of anomalies. Within semi‐arid and mesic grassland ecosystems, PPT gradient experiments indicate that short‐duration (1 year) PPT anomalies are often insufficient to drive nonlinear aboveground NPP responses. But long‐term studies, within desert to forest ecosystems, demonstrate how multi‐year PPT anomalies may result in increasing impacts on NPP through time, and thus alter PPT–NPP relationships. We present a conceptual model detailing how NPP responses to PPT anomalies may amplify with the duration of an event, how responses may vary in xeric vs. mesic ecosystems, and how these differences are most likely due to demographic mechanisms. Experiments that can unravel the independent and interactive impacts of the magnitude and duration of wet and dry PPT anomalies are needed, with multi‐site long‐term PPT gradient experiments particularly well‐suited for this task.

show abstract

Divergent forest sensitivity to repeated extreme droughts

Cited by 216 publications

References 68 publications

Risk of short‐term biodiversity loss under more persistent precipitation regimes

Risk of short‐term biodiversity loss under more persistent precipitation regimes

Drought by CO₂interactions in trees: a test of the water savings mechanism

Precipitation–productivity relationships and the duration of precipitation anomalies: An underappreciated dimension of climate change

Contact Info

Product

Resources

About

Divergent forest sensitivity to repeated extreme droughts

Cited by 216 publications

References 68 publications

Risk of short‐term biodiversity loss under more persistent precipitation regimes

Risk of short‐term biodiversity loss under more persistent precipitation regimes

Drought by CO2interactions in trees: a test of the water savings mechanism

Precipitation–productivity relationships and the duration of precipitation anomalies: An underappreciated dimension of climate change

Contact Info

Product

Resources

About

Drought by CO₂interactions in trees: a test of the water savings mechanism