Interspecific vs intraspecific patterns in leaf nitrogen of forest trees across nitrogen availability gradients. Issue 1 (6th June 2013)

• Record Type: Journal Article
• Authors: Dybzinski, Ray; Farrior, Caroline E.; Ollinger, Scott; Pacala, Stephen W.
• Is Part Of: New phytologist. Volume 200:Issue 1(2013)
• Page Start: 112
• Page End: 121
• Publication Date: 2013-06-06
• Subjects: Botany -- Periodicals; 580
• DOI: 10.1111/nph.12353
• Languages: English
• ISSNs: 0028-646X

Abstract

<abstract abstract-type="main" id="nph12353-abs-0001"> <title>Summary</title> <p> <list id="nph12353-list-0001" list-type="bullet"> <list-item> <p>Leaf nitrogen content (<italic>δ</italic>) coordinates with total canopy N and leaf area index (LAI) to maximize whole‐crown carbon (C) gain, but the constraints and contributions of within‐species plasticity to this phenomenon are poorly understood.</p> </list-item> <list-item> <p>Here, we introduce a game theoretic, physiologically based community model of height‐structured competition between late‐successional tree species. Species are constrained by an increasing, but saturating, relationship between photosynthesis and leaf N per unit leaf area. Higher saturating rates carry higher fixed costs.</p> </list-item> <list-item> <p>For a given whole‐crown N content, a C gain‐maximizing compromise exists between <italic>δ</italic> and LAI. With greater whole‐crown N, both <italic>δ</italic> and LAI increase within species. However, a shift in community composition caused by reduced understory light at high soil N availability (which competitively favors species with low leaf costs and consequent low optimal <italic>δ</italic>) counteracts the within‐species response, such that community‐level <italic>δ</italic> changes little with soil N availability. These model predictions provide a new explanation for the changes in leaf N per mass observed in data from three dominant broadleaf species in temperate deciduous forests of New England.</p> </list-item> <list-item> <p>Attempts to understand large‐scale patterns in vegetation often omit competitive interactions and intraspecific plasticity, but here both are essential to an understanding of ecosystem‐level patterns.</p> </list-item> </list> </p> </abstract>