Warming decreases desert ecosystem functioning by altering biocrusts in drylands
Abstract
Warming and precipitation fluctuations are changing desert ecosystems in global drylands. However, the effects of climate change on keystone species such as cryptogamic biocrust in drylands remain relatively under-investigated, even though biocrusts play a vital role in desert ecosystems. We conducted a long-term experiment (14 years) to simulate the responses of two main types of biocrusts to warming coupled with reduction in precipitation that was achieved by open-top chambers (OTCs) to simulate the predicted warming and precipitation decreasing under climate change scenario. We also conduct a structural analysis to evaluate the resulting changes in desert ecosystem functioning (carbon and nitrogen cycling). Neither warming and corresponding rainfall reduction treatments had a negative effect on lichen species richness, but both treatments reduced lichen cover and biomass. The negative effects of warming on moss-dominated crusts were much greater than those on lichen-dominated crusts. Although mosses and lichens had varying degrees of response to warming, the loss of mosses and decreased lichen cover and biomass, as well as the shortening of the wet time, resulted in a reduction in carbon and nitrogen fixation, soil enzyme activity and water-holding capacity of biocrusts and topsoil. These impacts collectively change the water balance of drylands and weaken the hydrological and biogeochemical function of biocrusts.
Synthesis and applications: Results from this long-term experiment suggest that the ecosystem C and N cycling and water balance of global drylands may be highly impacted by climate change, in part because of the response of biocrusts, which contribute an important implication for both dryland restoration and earth system dynamics.
README
This folder contains the datafiles for the article:
Title: Warming decreases desert ecosystem functioning by altering biocrusts in drylands
File list (files found within Data.zip)
- Li_et_al_2023_data_C_N_fixation
- Li_et_al_2023_data_Enzyme
- Li_et_al_2023_data_MWHC
- Li_et_al_2023_data_Quadrat
File descriptions
Li_et_al_2023_data_C_N_fixation:
Change in annual carbon fixation (A) and nitrogen fixation (B) (mean ± SE, n=3) for both lichen- and moss-dominated crusts under two warming treatments and the control during the experimental period. Annual carbon fixation was calculated by the sum of wet time-weighted carbon fixation ability of all rainfall events. Annual nitrogen fixation was calculated by the sum of wet time-weighted nitrogen fixation ability of all rainfall events.
Li_et_al_2023_data_Enzyme:
Changes in urease, invertase, catalase and dehydrogenase activity of lichen- and moss-dominated crust soil (0-5cm depth) after 6-, 10-, 12- and 14-year warming treatments and under the control.
Li_et_al_2023_data_MWHC:
Changes in Maximum Water Holding Capacity under 0.5℃ and 1.5℃-warming treatment. MWHC: Maximum Water Holding Capacity (mg/cm2);
Li_et_al_2023_data_Quadrat: A design Quadrat indicating the Richness, Biomass and Cover of each Biocrust Type (lichen and moss)
Treatment= ctrl: Control; Treatment= i05: 0.5℃-warming treatment; Treatment= i15: 1.5℃-warming treatment; C Fixation Ability: carbon fixation Ability; N Fixation Ability: nitrogen fixation Ability. SE, Standard Error.
Methods
See published article in the Journal of Applied Ecology for method details.