Carbon:nutrient balance hypothesis - Oxford Reference

, and (2005)Long- and short-term induction of defences in seedlings of Shorea leprosula (Dipterocarpaceae): support for the carbon:nutrient balance hypothesis. Journal of Tropical Ecology, 21. pp. 195-201.

The carbon-nutrient balance hypothesis: Its rise and fall

The Carbon±nutrient Balance Hypothesis: Its Rise and …

The carbon-nutrient balance hypothesis is dead; long …

Question: We present a general structural carbon - nutrient balance hypothesis parallel to Bryant et al.'s defensive chemistry hypothesis. Our hypothesis suggests that because herb species require a lower investment of carbon per unit length of stem than do woody plants, herbs should be at a competitive advantage where the leaf area of plants in the ground layer is limited by light (or fixed carbon, C) rather than soil resources (R) such as nutrients or water. We test the derivative predictions that in temperate deciduous forests (1) herb cover and species richness increase as soil resources increase, and (2) woody ground-layer cover, density, and species richness increase as soil resources decrease. Location: To maximize generality, the eight temperate deciduous forest sites were dispersed along an 800 km band from the Coastal Plain of eastern North Carolina to the Central Basin of middle Tennessee, USA. Methods: Soil nutrients and moisture, herb cover and woody stem densities were observed in six plots at each site, randomly located in high, medium, and low herb cover areas. Multiple regression, correlation, and Redundancy Analysis ordination were used to test predictions. Results: Plants with herbaceous (low C:R) stems are generally abundant where soil moisture and basic cations (Ca, Mg) are high (low C:R environments), and woody (high C:R) plant cover, basal area, stem density, and species richness are all greatest on dry or nutrient-poor soils (high C:R environments). Plots with intermediate soil resource availability and herb cover have the most species, and maximum herb species richness occurs at higher soil resource levels than maximum woody species richness. Conclusions: Our observations are consistent with our structural carbon - nutrient balance hypothesis.

Benefits of the Carbon-Nutrient Balance Hypothesis - …

N2 - Question: We present a general structural carbon - nutrient balance hypothesis parallel to Bryant et al.'s defensive chemistry hypothesis. Our hypothesis suggests that because herb species require a lower investment of carbon per unit length of stem than do woody plants, herbs should be at a competitive advantage where the leaf area of plants in the ground layer is limited by light (or fixed carbon, C) rather than soil resources (R) such as nutrients or water. We test the derivative predictions that in temperate deciduous forests (1) herb cover and species richness increase as soil resources increase, and (2) woody ground-layer cover, density, and species richness increase as soil resources decrease. Location: To maximize generality, the eight temperate deciduous forest sites were dispersed along an 800 km band from the Coastal Plain of eastern North Carolina to the Central Basin of middle Tennessee, USA. Methods: Soil nutrients and moisture, herb cover and woody stem densities were observed in six plots at each site, randomly located in high, medium, and low herb cover areas. Multiple regression, correlation, and Redundancy Analysis ordination were used to test predictions. Results: Plants with herbaceous (low C:R) stems are generally abundant where soil moisture and basic cations (Ca, Mg) are high (low C:R environments), and woody (high C:R) plant cover, basal area, stem density, and species richness are all greatest on dry or nutrient-poor soils (high C:R environments). Plots with intermediate soil resource availability and herb cover have the most species, and maximum herb species richness occurs at higher soil resource levels than maximum woody species richness. Conclusions: Our observations are consistent with our structural carbon - nutrient balance hypothesis.

According to the carbon‐nutrient balance hypothesis, this has implications for the production of secondary metabolites.
T1 - The carbon-nutrient balance hypothesis is dead; long live the carbon-nutrient balance hypothesis?

Plant defense against herbivory - Wikipedia

N2 - 1. Herbivory and litter decomposition are key controllers of ecosystem carbon and nutrient cycling. We hypothesized that foliar defences of plant species against vertebrate herbivores would reduce leaf digestibility and would subsequently, through 'afterlife effects', reduce litter decomposability. 2. We tested this hypothesis by screening 32 subarctic plant species, belonging to eight types in terms of life form and nutrient economy strategy, for (1) leaf digestibility in cow rumen juice; (2) biochemical and structural traits that might explain variation in digestibility; and (3) litter mass loss during simultaneous incubation in an outdoor subarctic litter bed. 3. Interspecific variation in green-leaf digestibility corresponded significantly with that in litter decomposability; this relationship was strongly driven by overall variation among the eight plant types (r = 0.92). The same relationship was not detectable within plant types in taxonomic relatedness tests. 4. Several biochemical and structural parameters (phenol-to-N ratio, lignin-to-N ratio) explained a significant part of the variation in leaf digestibility, but again only between and not within plant types. 5. Our results provide further support for the role played by foliar defence in the link between plant and soil via the decomposition pathway. They are also a new example of the potential control of plant functional types over carbon and nutrient dynamics in ecosystems.

According to the carbon-nutrient balance hypothesis, this has implications for the production of secondary metabolites.

Terpenes and phenolics in response to ..

In total, our results are largely consistent with the carbon-nutrient balance hypothesis, and warn that a combination of rising CO2 and nitrogen enrichment will affect the microcystin composition of harmful cyanobacteria. ID: 119541

carbon-nutrient balance hypothesis in within-species phytochemical variation of salix-lasiolepis

Impact of fertilisation on phenol content and growth …

The idea that the concentration of secondary metabolites in plant tissues is controlled by the availability of carbon and nitrogen in the environment has been termed the carbon±nutrient balance hypothesis (CNB). This hypothesis has been invoked both for prediction and for post hoc explanation of the results of hundreds of studies. Although it successfully predicts outcomes in some cases,it fails to such an extent that it cannot any longer be considered useful as a predictive tool. As information from studies has accumulated,many attempts have been made to save CNB,but these have been largely unsuccessful and have managed only to limit its utility. The failure of CNB is rooted in assumptions that are now known to be incorrect and it is time to abandon CNB because continued use of the hypothesis is now hindering understanding of plant±consumer interactions. In its place we propose development of theory with a firm evolutionary basis that is mechanistically sophisticated in terms of plant and herbivore physiology and genetics.