Foliar and soil δ¹⁵N values reveal increased nitrogen partitioning among species in diverse grassland communities

Abstract

ABSTRACT

The interaction between nitrogen and phosphorous is a strong predictor of intra-plant variation in nitrogen isotope composition in a desert species

“…However, our finding that roots tend to become more enriched in 15 N deeper into soil is reminiscent of the general patterns of increasing soil δ 15 N with depth, as reported in previous studies (Hobbie and Ouimette, 2009;Gubsch et al, 2011;Szpak, 2014). Since the present study did not measure soil δ 15 N profile, it remains to be determined whether the profile of root δ 15 N reflects that of soil δ 15 N.…”

“…As a result, the variations in the relative abundance of 15 N to 14 N, quantified as δ 15 N, of plants contain rich information about these processes (Högberg, 1997;Robinson, 2001;Evans, 2001;Dawson et al, 2002). For this reason, δ 15 N is often considered an integrator of terrestrial N cycling, and numerous studies have analyzed natural variations in plant δ 15 N across disturbance and successional stages (e.g., Hobbie et al, 2000;Wang et al, 2007;Resco et al, 2011;Hyodo et al, 2013), climate and topoedaphic gradients (e.g., Austin and Sala, 1999;Schulze et al, 1998;Martinelli et al, 1999;Amundson et al, 2003;Craine et al, 2005Craine et al, , 2009Bai et al, 2009), species (e.g., Cernusak et al, 2009;Gubsch et al, 2011), and types of mycorrhizal fungi Hobbie and Hög-berg, 2012). Other studies have used δ 15 N as an indicator of relative N and phosphorus (P) availability and limitation on plant growth (McKee et al, 2002;Wigand et al, 2007;Inglett et al, 2007;Mayor et al, 2014).…”

Progress and challenges in using stable isotopes to trace plant carbon and water relations across scales

“…Functional traits such as water or nutrient use strategies, carbon acquisition, growth behaviours, and phenological cycles contribute significantly to the observed variation in isotope composition (e.g. Warren and Adams, 2006;Gubsch et al, 2011;Salmon et al, 2011;Ramírez et al, 2012). However, the responsiveness of leaf 13 C as a functional tracer has to be verified for different communities and may differ with the predominant environmental constraints for plant growth and survival (e.g.…”

“…However, individual plants will not necessarily respond to environmental perturbations as "a community", but may respond according to species-specific traits and requirements and additionally depend on the interactions with the surrounding environment and other present species (e.g. Roscher et al, 2004;Gubsch et al, 2011). Competition and/or facilitation interactions between species, e.g.…”

Examining growth, yield and bean quality of Ethiopian coffee trees : towards optimizing resources and tree management

“…In this study, shade grown trees had greater plant height and larger specific leaf area, SLA, than those grown in full radiation (Chapter 2). Such morphological responses were also observed in other plant species ranging from grasses (Gubsch et al 2011) to legumes ) and to perennial trees like conifers (Claveau et al 2002). Taller stature enables plants to overtop neighbour plants and thus prevent having to grow in the shade.…”