AUTHOR=Liu Juan , Li Rui , Xu Jianhong , Fu Shenglei , Wan Songze 

TITLE=Effect of lime application on soil respiration is modulated by understory vegetation in subtropical Eucalyptus L’Hér. plantations

JOURNAL=Frontiers in Forests and Global Change

VOLUME=6

YEAR=2023

URL=https://www.frontiersin.org/journals/forests-and-global-change/articles/10.3389/ffgc.2023.1136474

DOI=10.3389/ffgc.2023.1136474

ISSN=2624-893X

ABSTRACT=<sec><title>Objective</title><p>Lime application and understory plant clearance are two common forest management methods employed to increase forest productivity in subtropical regions. However, the effect of these two management methods, or their combined application, on soil respiration in forest plantation settings is still not fully understood.</p></sec><sec><title>Methods</title><p>Here, a field experiment was conducted to determine how lime application, understory clearance, and their combined application, would impact total soil respiration (<italic>R</italic><sub><italic>s</italic></sub>), autotrophic respiration (<italic>R</italic><sub><italic>a</italic></sub>), and heterotrophic respiration (<italic>R</italic><sub><italic>h</italic></sub>) in a Chinese subtropical <italic>Eucalyptus</italic> plantation. Changes in soil microclimate and microbial community (PLFAs), as well as <italic>Eucalyptus</italic> fine root biomass were also assessed.</p></sec><sec><title>Results</title><p>Lime application stimulated <italic>R</italic><sub><italic>h</italic></sub>, but decreased <italic>R</italic><sub><italic>a</italic></sub> of understory vegetation (primarily <italic>Dicranopteris dichotoma</italic>), thus consequently inhibiting <italic>R</italic><sub><italic>s</italic></sub>. Understory clearance also reduced <italic>R</italic><sub><italic>s</italic></sub>, primarily due to reductions in soil PLFAs and associated <italic>R</italic><sub><italic>h</italic></sub>, and <italic>R</italic><sub><italic>a</italic></sub> of understory vegetation. Since the increase in <italic>R</italic><sub><italic>h</italic></sub> induced by lime application was greater than the decrease in <italic>R</italic><sub><italic>h</italic></sub> caused by understory clearance, the combined application of lime application and understory clearance decreased <italic>R</italic><sub><italic>s</italic></sub> primarily by reducing understory root respiration.</p></sec><sec><title>Conclusion</title><p>Our observations suggest that understory plants can modulate the effect of lime application on <italic>R</italic><sub><italic>s</italic></sub>, highlighting the important role of understory vegetation in regulating soil carbon cycling in subtropical <italic>Eucalyptus</italic> plantations. We concluded that the potential interactive effects should be considered in developing management practices that optimize the yield and sustainability of subtropical plantations.</p></sec>