Soil biomass-related enzyme activity indicates minimal functional changes after 16 years of persistent drought treatment in a Mediterranean holm oak forest

被引：8

作者：

Asensio, Dolores ^{[1
,2
,6
]}

Zuccarini, Paolo ^{[1
,2
]}

Sardans, Jordi ^{[1
,2
]}

Maranon-Jimenez, Sara ^{[1
,2
]}

Mattana, Stefania ^{[1
,2
]}

Ogaya, Roma ^{[1
,2
]}

Mu, Zhaobin ^{[1
,2
,3
,4
,5
]}

Llusia, Joan ^{[1
,2
]}

Penuelas, Josep ^{[1
,2
]}

机构：

[1] UAB, CSIC, Global Ecol CREAF CSIC, Barcelona 08193, Catalonia, Spain

[2] CREAF, Cerdanyola Del Valles, Barcelona 08193, Catalonia, Spain

[3] Chinese Acad Sci, State Key Lab Organ Geochem, Guangzhou 510640, Peoples R China

[4] Chinese Acad Sci, Guangzhou Inst Geochem, Guangdong Key Lab Environm Protect & Resources Uti, Guangzhou 510640, Peoples R China

[5] CAS Ctr Excellence Deep Earth Sci, Guangzhou 510640, Peoples R China

[6] Free Univ Bozen Bolzano, Fac Agr Environm & Food Sci, I-39100 Bolzano, Italy

来源：

SOIL BIOLOGY & BIOCHEMISTRY | 2024年 / 189卷

关键词：

Acid and alkaline phosphatases; Beta-glucosidase; Climate change; Drought; Drought-resistance; Mediterranean holm oak forest; Microbial functional adaptation; Phosphorus; Protease; Soil enzymes; Urease; PHOSPHATASE-ACTIVITY; ECOENZYMATIC STOICHIOMETRY; PLANT; ACCUMULATION; DYNAMICS; NITROGEN; STRESS; ACID;

D O I：

10.1016/j.soilbio.2023.109281

中图分类号：

S15 [土壤学];

学科分类号：

0903 ; 090301 ;

摘要：

Long-term drought impacts soil microbial responses and enzymatic activity, affecting carbon budget and nutrient cycling in terrestrial ecosystems. We examined a Mediterranean holm oak forest subjected to 16 years of drought treatment to understand the effects on soil organic matter decomposition, nutrient cycling, and enzymatic activity. We compared potential and biomass-related (normalized to microbial biomass) soil enzyme activity with measurements taken 10 years earlier. Relationships between potential enzyme activity, soil moisture, temperature, nutrient availability, and plant/microbial activity were explored. The prolonged drought led to decreased potential activities of all enzymes, especially acid phosphatase, protease, and urease. However, biomass-related activities of protease, urease, and phosphatase were unaffected. Interestingly, biomass-related beta-glucosidase activity increased during dry seasons, indicating a functional adaptation for carbon acquisition during extreme dry conditions. The negative impact of drought on potential enzyme activity intensified over time, particularly during summer when drought intensity increased. Soil water availability, microbial biomass, and nutrient availability strongly influenced potential enzyme activity. Long-term drought and summer aridity led to increased substrate accumulation in the soil. However, no significant changes were observed in biomass-related activities of nitrogen and phosphorus-acquiring enzymes. This lack of change is likely attributed to a decrease in the absolute potential enzyme activity capacity, caused by a reduction in microbial biomass in drought-affected plots, thereby favoring substrate accumulation. Specific functional adaptations were observed, including increased carbon acquisition by soil microbes during extreme summer drought. Long-term water scarcity in water-limited ecosystems diminishes the system's capacity to acquire resources through enzyme production, impacting mineralization and nutrient dynamics. Future climate scenarios may entail reduced ecosystem-level mineralization, carbon and nitrogen shifts from plants to soil, compromising plant control over nutrients, and increasing the risk of resource loss through leaching and erosion.

引用

页数：12