scholarly journals Evidence of a general 2/3-power law of scaling leaf nitrogen to phosphorus among major plant groups and biomes

2009 ◽  
Vol 277 (1683) ◽  
pp. 877-883 ◽  
Author(s):  
Peter B. Reich ◽  
Jacek Oleksyn ◽  
Ian J. Wright ◽  
Karl J. Niklas ◽  
Lars Hedin ◽  
...  
Keyword(s):  
Power Law ◽  
Plant Traits ◽  
High Growth ◽  
Terrestrial Ecosystems ◽  
Leaf Nitrogen ◽  
Scaling Relations ◽  
Nitrogen And Phosphorus ◽  
Form And Function ◽  
General Relations ◽  
And Function

Scaling relations among plant traits are both cause and consequence of processes at organ-to-ecosystem scales. The relationship between leaf nitrogen and phosphorus is of particular interest, as both elements are essential for plant metabolism; their limited availabilities often constrain plant growth, and general relations between the two have been documented. Herein, we use a comprehensive dataset of more than 9300 observations of approximately 2500 species from 70 countries to examine the scaling of leaf nitrogen to phosphorus within and across taxonomical groups and biomes. Power law exponents derived from log–log scaling relations were near 2/3 for all observations pooled, for angiosperms and gymnosperms globally, and for angiosperms grouped by biomes, major functional groups, orders or families. The uniform 2/3 scaling of leaf nitrogen to leaf phosphorus exists along a parallel continuum of rising nitrogen, phosphorus, specific leaf area, photosynthesis and growth, as predicted by stoichiometric theory which posits that plants with high growth rates require both high allocation of phosphorus-rich RNA and a high metabolic rate to support the energy demands of macromolecular synthesis. The generality of this finding supports the view that this stoichiometric scaling relationship and the mechanisms that underpin it are foundational components of the living world. Additionally, although abundant variance exists within broad constraints, these results also support the idea that surprisingly simple rules regulate leaf form and function in terrestrial ecosystems.

scholarly journals Global leaf nitrogen and phosphorus stoichiometry and their scaling exponent

2017 ◽  
Vol 5 (5) ◽  
pp. 728-739 ◽  
Author(s):  
Di Tian ◽  
Zhengbing Yan ◽  
Karl J Niklas ◽  
Wenxuan Han ◽  
Jens Kattge ◽  
...  
Keyword(s):  
Functional Groups ◽  
Woody Plants ◽  
Terrestrial Ecosystems ◽  
Life Forms ◽  
Leaf Nitrogen ◽  
Scaling Exponent ◽  
Nitrogen And Phosphorus ◽  
Data Set ◽  
Scaling Relationships ◽  
Leaf N

Abstract Leaf nitrogen (N) and phosphorus (P) concentrations constrain photosynthetic and metabolic processes, growth and the productivity of plants. Their stoichiometry and scaling relationships regulate the allocation of N and P from subcellular to organism, and even ecosystem levels, and are crucial to the modelling of plant growth and nutrient cycles in terrestrial ecosystems. Prior work has revealed a general biogeographic pattern of leaf N and P stoichiometric relationships and shown that leaf N scales roughly as two-thirds the power of P. However, determining whether and how leaf N and P stoichiometries, especially their scaling exponents, change with functional groups and environmental conditions requires further verification. In this study, we compiled a global data set and documented the global leaf N and P concentrations and the N:P ratios by functional group, climate zone and continent. The global overall mean leaf N and P concentrations were 18.9 mg g−1 and 1.2 mg g−1, respectively, with significantly higher concentrations in herbaceous than woody plants (21.72 mg g−1 vs. 18.22 mg g−1 for N; and 1.64 mg g−1 vs. 1.10 mg g−1 for P). Both leaf N and P showed higher concentrations at high latitudes than low latitudes. Among six continents, Europe had the highest N and P concentrations (20.79 and 1.54 mg g−1) and Oceania had the smallest values (10.01 and 0.46 mg g−1). These numerical values may be used as a basis for the comparison of other individual studies. Further, we found that the scaling exponent varied significantly across different functional groups, latitudinal zones, ecoregions and sites. The exponents of herbaceous and woody plants were 0.659 and 0.705, respectively, with significant latitudinal patterns decreasing from tropical to temperate to boreal zones. At sites with a sample size ≥10, the values fluctuated from 0.366 to 1.928, with an average of 0.841. Several factors including the intrinsic attributes of different life forms, P-related growth rates and relative nutrient availability of soils likely account for the inconstant exponents of leaf N vs. P scaling relationships.

Upscaling plant traits to ecosystem level: blending local biodiversity,  global traits databases, and remote sensing data.

2021 ◽  
Author(s):  
Álvaro Moreno-Martínez ◽  
Jose E. Adsuara ◽  
Jordi Muñoz-Marí ◽  
Emma Izquierdo-Verdiguier ◽  
Jens Katge ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Plant Traits ◽  
Nitrogen Concentration ◽  
Great Influence ◽  
Remote Sensing Data ◽  
Terrestrial Ecosystems ◽  
Leaf Nitrogen ◽  
Global Biodiversity Information Facility ◽  
Ecosystem Level ◽  
Selection Of

<p>Plant functional traits have great influence in how terrestrial ecosystems function. This key information is however generally oversimplified in most Earth system models (ESMs) and is typically represented by a number of static, empirically fixed values assigned to a selection of plant functional types (PFTs). This leads to reducing the diversity of plant communities into a relatively low number of categories and key variability within individual PFTs is lost. Subgrid processes are thus underrepresented and accuracy compromised.</p><p>The TRY global traits database contains the largest set of in-situ trait observations for numerous species around the globe. Despite the large number of species and samples included in trait databases, such as TRY, they are sparse compared to the overall richness and diversity of species globally. We propose the use of the massive geolocated plant occurrence data from the Global Biodiversity Information Facility (GBIF) as ancillary source of information to better capture species distributions, especially in locations where TRY data are missing. </p><p>As a first order approach, GBIF was used to estimate species abundances for a given study area (contiguous United States), and they were further corrected with high resolution, subpixel maps of PFT derived via remote sensing and machine learning upscaling.  This information was used to provide ecosystem level trait estimates for a selection of plant traits (specific leaf area and leaf nitrogen concentration). The proposed approach allows us to link local biodiversity composition from GBIF with a more precise and realistic representation of plant community composition coming from remote sensing information for ecosystem-level trait estimation. Among many possible applications of these data, the addition of the produced trait estimates to improve ESMs estimations could be very valuable to improve the understanding and monitoring of the biosphere.</p>

Scanning tunneling microscopy (STM) of DNA and RNA

1989 ◽  
Vol 47 ◽  
pp. 34-35
Author(s):  
Patricia G. Arscott ◽  
Gil Lee ◽  
Victor A. Bloomfield ◽  
D. Fennell Evans
Keyword(s):  
Molecular Structures ◽  
Inorganic Materials ◽  
Resolving Power ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Form And Function ◽  
Dna And Rna ◽  
Calf Thymus ◽  
And Function ◽  
The Relationship

STM is one of the most promising techniques available for visualizing the fine details of biomolecular structure. It has been used to map the surface topography of inorganic materials in atomic dimensions, and thus has the resolving power not only to determine the conformation of small molecules but to distinguish site-specific features within a molecule. That level of detail is of critical importance in understanding the relationship between form and function in biological systems. The size, shape, and accessibility of molecular structures can be determined much more accurately by STM than by electron microscopy since no staining, shadowing or labeling with heavy metals is required, and there is no exposure to damaging radiation by electrons. Crystallography and most other physical techniques do not give information about individual molecules.We have obtained striking images of DNA and RNA, using calf thymus DNA and two synthetic polynucleotides, poly(dG-me5dC)·poly(dG-me5dC) and poly(rA)·poly(rU).

Re-examining the form and function of superstition

2011 ◽  
Author(s):  
Scott Fluke ◽  
Russell J. Webster ◽  
Donald A. Saucier
Keyword(s):  
Form And Function ◽  
And Function

A New Form and Function for Personality

2013 ◽  
Author(s):  
Joshua Wilt ◽  
William Revelle
Keyword(s):  
Form And Function ◽  
New Form ◽  
And Function

Ausnahmesegment

2018 ◽  
Vol 48 (191) ◽  
Author(s):  
Barbara Schönig
Keyword(s):  
Welfare State ◽  
Social Housing ◽  
Integrated Approach ◽  
New Paradigm ◽  
Development Models ◽  
Form And Function ◽  
Institutional Organization ◽  
National Welfare ◽  
And Function ◽  
The Welfare State

Going along with the end of the “golden age” of the welfare state, the fordist paradigm of social housing has been considerably transformed. From the 1980s onwards, a new paradigm of social housing has been shaped in Germany in terms of provision, institutional organization and design. This transformation can be interpreted as a result of the interplay between the transformation of national welfare state and housing policies, the implementation of entrepreneurial urban policies and a shift in architectural and urban development models. Using an integrated approach to understand form and function of social housing, the paper characterizes the new paradigm established and nevertheless interprets it within the continuity of the specific German welfare resp. housing regime, the “German social housing market economy”.

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