Abstract
Gap formation favors the growth of understory plants and affects the decomposition process of plant debris inside and outside of gaps. Little information is available regarding how bioelement release from shrub litter is affected by gap formation during critical periods. The release of carbon (C), nitrogen (N), and phosphorus (P) in the foliar litter of Fargesia nitida and Salix paraplesia in response to gap locations was determined in an alpine forest of the eastern Qinghai-Tibet Plateau via a 2-year litter decomposition experiment. The daily release rates of C, N, and P increased from the closed canopy to the gap centers during the two winters, the two later growing seasons and the entire 2 years, whereas this trend was reversed during the two early growing seasons. The pairwise ratios among C, N, and P converged as the litter decomposition proceeded. Compared with the closed canopy, the gap centers displayed higher C:P and N:P ratio but a lower C:N ratio as the decomposition proceeded. Alpine forest gaps accelerate the release of C, N, and P in decomposing shrub litter, implying that reduced snow cover resulting from vanishing gaps may inhibit the release of these elements in alpine forests.
Highlights
Physical structure of the litter and improve its decomposability[21]
Consistent with the hypothesis that alpine forest gaps can accelerate shrub foliar litter C, N, and P release during the cold season, the results of this study indicate that the VL of C, N, and P in the two snow-formation periods, snow-cover periods, and snow-melting periods was greater in the gap centers than below the expanded canopy or closed canopy
Thicker snow cover in the gap centers serves as an insulator (Fig. 4a) that can maintain sufficiently warm temperatures for biotic activity[15,27]
Summary
Physical structure of the litter and improve its decomposability[21]. A much thicker snow cover can form early on the forest floor in the center of the gap, and ablation may occur later there[22,23]. In contrast, gap centers in alpine forests often exhibits a higher soil surface temperature than the gap edge and the closed canopy due to the center’s greater amount of solar irradiation This warmer temperature might be the dominant factor that drives litter carbon and nutrients release via its indirect effects on hydrothermal dynamics and microbial activities of microenvironment[21]. To test the hypothesis mentioned above, a field experiment was performed using litterbags containing foliar litter from two dominant understory shrubs (Fargesia nitida and Salix paraplesia) These bags were distributed from the gap centers to the closed canopy on the forest floor in three selected gaps in the alpine fir forest. The results are expected to provide insights into the roles of shrubs and forest gap formation on carbon, nitrogen and phosphorus cycles in high-altitude forest ecosystems
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
