TY - JOUR
T1 - Stronger microbial decay of recalcitrant carbon in tropical forests than in subtropical and temperate forest ecosystems in China
AU - Zhou, Sha
AU - Chen, Lan
AU - Wang, Jieying
AU - He, Liyuan
AU - Wang, Jun
AU - Ren, Chengjie
AU - Guo, Yaoxin
AU - Zhao, Fazhu
N1 - Publisher Copyright:
© 2022
PY - 2022/8
Y1 - 2022/8
N2 - Soil enzymes are the most potent bioactive components in forest ecosystems. Cellulases and ligninases are vital carbon (C)-degrading enzymes that target different C pools. The ratio of ligninase-to-cellulase activity is good indicator for microbial soil C preference, play an important role in soil C cycling. However, our understanding of enzyme ratios and their drivers across forest ecosystems remains unclear. In this study, we hypothesized that (i) the ligninase-to-cellulase ratio increased from temperate forests to tropical forest ecosystems, and (ii) the dominant factors would be microbial abundances. About 2–3 kg of topsoil (0–10 cm) from each of the ten forest ecosystems were collected across a 3425 km gradient in China between July and August 2019. We analyzed the biogeographic patterns of ligninase and cellulase activities and the ratio of ligninase-to-cellulase activities to determine how this ratio responded to climatic factors, soil properties and substrates, and microbial abundances across the forest ecosystems along the latitudinal gradient. Our findings showed that the average soil ligninase activity was 3.49 nmol h−1 g−1, whereas the average soil cellulase activity was 525.26 nmol h−1 g−1 across the forest ecosystems sampled. The average activity ratio of ligninase-to-cellulase in tropical forest ecosystems was 27.9% higher than that in subtropical forests and 64.2% higher than that in temperate forest ecosystems. The partial least squares path model demonstrated that the ligninase-to-cellulase activity ratio was significantly negatively correlated with soil substrates (r = -0.94, p < 0.001) and significantly positively correlated with microbial abundances (r = 0.38, p < 0.01). The variation partitioning analysis further revealed that soil substrates explained 19.4% variation regarding ligninase-to-cellulase ratio, whereas microbial abundance (fungal abundance) contributed 2.8%. This study provides crucial information about the distribution of enzyme ratios along the latitude gradient, highlights the microbial utilization of recalcitrant C pools in tropical forests, and provides an insight into the response of the global C cycle under a changing climate.
AB - Soil enzymes are the most potent bioactive components in forest ecosystems. Cellulases and ligninases are vital carbon (C)-degrading enzymes that target different C pools. The ratio of ligninase-to-cellulase activity is good indicator for microbial soil C preference, play an important role in soil C cycling. However, our understanding of enzyme ratios and their drivers across forest ecosystems remains unclear. In this study, we hypothesized that (i) the ligninase-to-cellulase ratio increased from temperate forests to tropical forest ecosystems, and (ii) the dominant factors would be microbial abundances. About 2–3 kg of topsoil (0–10 cm) from each of the ten forest ecosystems were collected across a 3425 km gradient in China between July and August 2019. We analyzed the biogeographic patterns of ligninase and cellulase activities and the ratio of ligninase-to-cellulase activities to determine how this ratio responded to climatic factors, soil properties and substrates, and microbial abundances across the forest ecosystems along the latitudinal gradient. Our findings showed that the average soil ligninase activity was 3.49 nmol h−1 g−1, whereas the average soil cellulase activity was 525.26 nmol h−1 g−1 across the forest ecosystems sampled. The average activity ratio of ligninase-to-cellulase in tropical forest ecosystems was 27.9% higher than that in subtropical forests and 64.2% higher than that in temperate forest ecosystems. The partial least squares path model demonstrated that the ligninase-to-cellulase activity ratio was significantly negatively correlated with soil substrates (r = -0.94, p < 0.001) and significantly positively correlated with microbial abundances (r = 0.38, p < 0.01). The variation partitioning analysis further revealed that soil substrates explained 19.4% variation regarding ligninase-to-cellulase ratio, whereas microbial abundance (fungal abundance) contributed 2.8%. This study provides crucial information about the distribution of enzyme ratios along the latitude gradient, highlights the microbial utilization of recalcitrant C pools in tropical forests, and provides an insight into the response of the global C cycle under a changing climate.
KW - Carbon pools
KW - Forest soil
KW - Latitudinal gradient
KW - Ligninase-to-cellulase ratio
KW - Soil substrates
UR - http://www.scopus.com/inward/record.url?scp=85129767211&partnerID=8YFLogxK
U2 - 10.1016/j.catena.2022.106351
DO - 10.1016/j.catena.2022.106351
M3 - Article
AN - SCOPUS:85129767211
SN - 0341-8162
VL - 215
JO - Catena
JF - Catena
M1 - 106351
ER -