Dynamics of nitrogen and phosphorus accumulation and their stoichiometry along a chronosequence of forest primary succession in the Hailuogou Glacier retreat area, eastern Tibetan Plateau

Abstract

As the two limiting nutrients for plants in most terrestrial ecosystems, nitrogen (N) and phosphorus (P) are essential for the development of succession forests. Vegetation N:P stoichiometry is a useful tool for detecting nutrient limitation. In the present work, chronosequence analysis was employed to research N and P accumulation dynamics and their stoichiometry during forest primary succession in a glacier retreat area on the Tibetan Plateau. Our results showed that: (1) total ecosystem N and P pools increased from 97 kg hm−2 to 7186 kg hm−2 and 25 kg hm−2 to 487 kg hm−2, respectively, with increasing glacier retreat year; (2) the proportion of the organic soil N pool to total ecosystem N sharply increased with increasing glacier retreat year, but the proportion of the organic soil and the vegetation P pools to the total ecosystem P was equivalent after 125 y of recession; (3) the N:P ratio for tree leaves ranged from 10.1 to 14.3, whereas the N:P ratio for total vegetation decreased form 13.3 to 8.4 and remained constant after 35 y of recession, and the N:P ratio for organic soil increased from 0.2 to 23.1 with increasing glacier retreat. These results suggested that organic soil N increased with increasing years of glacier retreat, which may be the main sink for atmospheric N, whereas increased P accumulation in vegetation after 125 y of recession suggested that much of the soil P was transformed into the biomass P pool. As the N:P ratio for vegetation maintained a low level for 35–125 y of recession, we suggested that N might be the main limiting element for plant growth in the development of this ecosystem.

Initial carbonate weathering is linked with vegetation development along a 127-year glacial retreat chronosequence in the subtropical high mountainous Hailuogou region (SW China)

“…Previous research on biologically relevant elements in the Hailuogou region focused on the change in C, N and P mass ratios and stocks (e.g., Bing et al 2016b;He and Tang 2008;Wu et al 2015;Yang et al 2021;Zhang et al 2021;Zhou et al 2013) or contamination by trace metals (e.g. Bing et al 2016aBing et al , 2019Luo et al 2015;Wang et al 2020).…”

“…Zhou et al (2016b) reported that weathering processes in the Hailuogou are initially dominated by the weathering of carbonates followed by a more intense biogeochemical weathering (>80 yr) because of lower pH values. In a recent study, Yang et al (2021) suggested that N is the main growth-limiting element in the Hailuogou area based on N:P stoichiometric ratios in leaves. Wang et al (2021) recently reported a positive effect of pioneer N 2 -fixing plants on the establishment of other non-N 2 -fixing species after glacier retreat.…”

“…Deciduous tree species usually have higher Ca, Mg and K concentration in leaves and greater foliar biomass than coniferous tree species (Ericsson 1994), which causes larger metal fluxes with litterfall in deciduous than coniferous forests (Carnol and Bazgir 2013). Although N and phosphorous (P) are considered the most commonly limiting nutrients affecting biomass production in terrestrial ecosystems (Elser et al 2007;LeBauer and Treseder 2008;Vitousek and Howarth 1991;Lei et al 2021;Yang et al 2021), previous studies have shown that Ca, Mg and K can have a great influence on tree growth and vegetation development (Baribault et al 2012;Burstrom 1968;Epron et al 2012;Federer et al 1989;McLaughlin and Wimmer 1999;Paoli and Curran 2007;Wright et al 2011). Sodium (Na) can also be taken up and used by vegetation (Amtmann and Sanders 1999).…”

Nitrogen Preference of Dominant Species during Hailuogou Glacier Retreat Succession on the Eastern Tibetan Plateau

“…The acceleration of glacier melting caused by global warming in recent years has created bare land in different periods which can be accurately measured, providing ideal places to study the primary succession of vegetation [ 27 , 28 , 29 ]. Most studies on vegetation succession in glacial retreat areas focus on the vegetation composition and structure, soil nutrient status and the coupling relationship of plant-soil-microbial interactions [ 30 , 31 , 32 , 33 ]. However, the N utilization strategies of dominant plants at different stages of primary succession are poorly understood, and therefore, the patterns and mechanisms for plants adjusting their N preference to adapt to environmental changes remain to be further studied.…”

Spatial Differentiation of Ecological Stoichiometry of Nitrogen and Phosphorus in Mollic Epipedon of China

“…ese elements can a ect the physical energy cycle and terrestrial ecosystem balance [1]. Over the past few years, numerous studies have reported spatial variations and in uencing factors for soil N/P chemometric characteristics in terrestrial ecosystems [2,3]. A typical study is Cambardella et al [4].…”