• History and trends in ecological stoichiometry research from 1992 to 2019: a scientometric analysis

      Li, Hailiang; Crabbe, M. James C.; Chen, Haikui; Gansu Agricultural University; Oxford University; University of Bedfordshire; Shanxi University; North Minzu University (MDPI, 2020-10-27)
      Ecological stoichiometry (ES), as an ecological theory, provides a framework for studying various ecological processes, and it has been applied successfully in fields ranging from nutrient dynamics to biogeochemical cycling. Through the application of ES theory, researchers are beginning to understand many diverse ecological topics. The aim of this paper was to identify the main characteristics of ES, especially to clarify the evolution, and potential trends of this field for future ecological studies. We used CiteSpace software to conduct a bibliometric review of ES research publications from 1992 to 2019 extracted from the Web of Science. The results showed that the United States has been a major contributor to this field; approximately half of the top 15 academic institutions contributing to ES research were in the United States. Although the largest number of publications on ES were from China, the impact of these academic papers has thus far been less than that of the papers from other countries. Moreover, none of the top 15 authors or cited authors contributing to publications on ES from 1992 to 2019 were from China. ES research has developed rapidly and has changed from single-discipline ES studies to a multidisciplinary “auxiliary tool” used in different fields. Overall, ES shows great research potential and application value, especially for studies on nutrient cycling, ecosystem sustainability and biogeochemical cycling.
    • Seasonal variations in carbon, nitrogen and phosphorus concentrations and C:N:P stoichiometry in different organs of a Larix principis-rupprechtii Mayr. plantation in the Qinling Mountains, China

      Li, Haliang; Crabbe, M. James C.; Xu, Fuli; Wang, Weiling; Ma, Lihua; Niu, Ruilong; Gao, Xing; Li, Xingxing; Zhang, Pei; Ma, Xin; et al. (Public library of science, 2017-09-22)
      Understanding how concentrations of elements and their stoichiometry change with plant growth and age is critical for predicting plant community responses to environmental change. Weusedlong-term field experiments to explore how the leaf, stem and root carbon (C), nitrogen (N) and phosphorous (P) concentrations and their stoichiometry changed with growth and stand age in a L.principis-rupprechtii Mayr. plantation from 2012–2015 in the Qinling Mountains, China. Our results showed that the C, N and P concentrations and stoichiometric ratios in different tissues of larch stands were affected by stand age, organ type andsampling month and displayed multiple correlations with increased stand age in different growing seasons. Generally, leaf C and N concentrations were greatest in the fast-growing season, but leaf P concentrations were greatest in the early growing season. However, no clear seasonal tendencies in the stem and root C, N and P concentrations were observed with growth. In contrast to N and P, few differences were found in organ-specific C concentrations. Leaf N:P was greatest in the fast-growing season, while C:N and C:P were greatest in the late-growing season. No clear variations were observed in stem and root C:N, C:P andN:Pthroughout the entire growing season, but leaf N:P was less than 14, suggesting that the growth of larch stands was limited by N in our study region. Compared to global plant element concentrations and stoichiometry, the leaves of larch stands had higher C, P, C:NandC:PbutlowerNandN:P,andtherootshadgreater PandC:NbutlowerN,C:Pand N:P. Our study provides baseline information for describing the changes in nutritional elements with plant growth, which will facilitates plantation forest management and restoration, and makes avaluable contribution to the global data pool on leaf nutrition and stoichiometry.
    • Seasonal variations in carbon, nitrogen and phosphorus concentrations and C:N:P stoichiometry in the leaves of differently aged Larix principis-rupprechtii Mayr. plantations

      Li, Hailiang; Crabbe, M. James C.; Xu, Fuli; Wang, Weiling; Niu, Ruilong; Gao, Xing; Zhang, Pei; Chen, Haikui; Northwest A & F University, Yangling; University of Oxford; et al. (MDPI, 2017-09-30)
      The concentrations and stoichiometry of certain elements (carbon, nitrogen and phosphorus) are critical to the maintenance of plant functional and environmental adaptation during plant growth. We explore how the concentrations of C, N and P and the ratios of C:N, C:P, and N:P in the leaves of differently aged Larix principis-rupprechtii Mayr. plantations changed with growing season and stand age from 2012 to 2015 in the Qinling Mountains, China. The results showed that the element concentration and stoichiometric ratios in leaves were significantly affected by sampling month, stand age and sampling year; and multiple correlations with stand age were observed in different growing seasons. Compared to global element concentrations and stoichiometry in plants, the leaves of larch stands in the study region had higher C and P concentrations and C:N and C:P ratios but lower N concentrations and N:P ratios than global levels. The leaf N:P ratios of all of the larch stands were generally less than 14, suggesting that the growth of larch stands was limited by N in the study region. Our study facilitates the management and restoration of forest plantation and provides a valuable contribution to the global pool of leaf nutrition and stoichiometry data.