Flower litters of alpine plants affect soil nitrogen and phosphorus rapidly in the eastern Tibetan Plateau

Abstract

Abstract. Litters of reproductive organs have rarely been studied despite their role in allocating nutrients for offspring reproduction. This study determines the mechanism through which flower litters efficiently increase the available soil nutrient pool. Field experiments were conducted to collect plant litters and calculate biomass production in an alpine meadow of the eastern Tibetan Plateau. C, N, P, lignin, cellulose content, and their relevant ratios of litters were analyzed to identify their decomposition features. A pot experiment was performed to determine the effects of litter addition on the soil nutrition pool by comparing the treated and control samples. The litter-bag method was used to verify decomposition rates. The flower litters of phanerophyte plants were comparable with non-flower litters. Biomass partitioning of other herbaceous species accounted for 10–40 % of the aboveground biomass. Flower litter possessed significantly higher N and P levels but less C ∕ N, N ∕ P, lignin ∕ N, and lignin and cellulose concentrations than leaf litter. The litter-bag experiment confirmed that the flower litters of Rhododendron przewalskii and Meconopsis integrifolia decompose approximately 3 times faster than mixed litters within 50 days. Pot experiment findings indicated that flower litter addition significantly increased the available nutrient pool and soil microbial productivity. The time of litter fall significantly influenced soil available N and P, and soil microbial biomass. Flower litters fed the soil nutrition pool and influenced nutrition cycling in alpine ecosystems more efficiently because of their non-ignorable production, faster decomposition rate, and higher nutrient contents compared with non-flower litters. The underlying mechanism can enrich nutrients, which return to the soil, and non-structural carbohydrates, which feed and enhance the transitions of soil microorganisms.

Seasonal Dynamics of Litterfall in a Sub-Alpine Spruce-Fir Forest on the Eastern Tibetan Plateau: Allometric Scaling Relationships Based on One Year of Observations

“…The litter of reproductive organs has rarely been studied despite the key role of these organs in allocating nutrients to offspring [10]. In the present study, the fruit litter of deciduous species occurred mostly in the middle growing season (July and August), and the most conifer cones were collected in the snow-melting period (April).…”

“…Flower litter was concentrated in June and July and contributed 1.5% to the total litter (Table 1). Flower litter production has been shown to influence nutrient cycling in high-frigid ecosystems [10]. Flower litter showed a significant seasonal pattern as it mainly occurred in the rainy season when temperatures were high and solar radiation was adequate [14].…”

Seasonal and interannual dynamics of soil microbial biomass and available nitrogen in an alpine meadow in the eastern part of Qinghai–Tibet Plateau, China

“…Early flowering plants, such as Primula sikkimensis, Androsace umbellata, and Caltha palustris, dominate the community as soon as the snow melts; Polygonum macrophyllum, Ranunculus tanguticus, and Carex melanocephala dominate the middle growing season; and Saussurea hieracioides and Gentiana sinoornata usually dominate the late growing season (Bo Xu, unpublished data, collected from 2011 to 2013). The predominant soil type is mountain dark brown soil and Mat Cry-gelic Cambisols (i.e., silty loam inceptisol; Chinese Soil Taxonomy Research Group, 1995;Soil Survey Staff, 2014;Wang et al, 2016).…”

“…The MBC and MBN were then calculated by subtracting the C and N contents of non-chloroform-treated samples from that of chloroformtreated samples, respectively. Correction factors of 0.45 for C and 0.54 for N were used to convert the chloroform labile C and N to microbial C and N, respectively (Brookes et al, 1985;Lin, 2010;Wang et al, 2016).…”

Variation in snow cover drives differences in soil properties and microbial biomass of BSCs in the Gurbantunggut Desert—3 years of snow manipulations

“…The increased depth and duration of seasonal snow cover can facilitate cryptogamous and microbial growth by influencing soil temperature and soil freezing(Groffman et al, 2011;Tan et al, 2014;Wang, Xu, Wu, Gao, & Shi, 2016) Zhao et al (2016). It is clear that SWC were positively influenced by increased snow cover at depths of 0-5 cm in the three types of BSCs after 3 years of snow manipulation.…”