Tagged: carbon


Effect of simulated warming on Leymus chinensis grasslands of northeast China

Mean global temperatures have risen by almost 1°C since 1850 and are predicted to continue to rise through to the end of the century. Understanding how grasses are affected by a long-term increase in temperature is crucial to predicting the future impacts of climate change. Grasslands occupy over 3.5 billion hectares of land and store 20 % of the world’s soil carbon. Yet few experimental studies have comprehensively investigated how warming affects the dynamics of grassland ecosystems. In a recent study published in AoBP, Guo et al. investigated the effects of simulated elevated temperatures on Leymus chinensis grassland in Northeast China. Measurements of soil...

Continue reading Effect of simulated warming on Leymus chinensis grasslands of northeast China


Models of plants

FSPM-based investigation of plant interactions in complex wheat canopies

Functional–structural plant models (FSPMs) explicitly describe individual plant architecture, making this approach suitable for unravelling plant–plant interactions in complex canopies. Barillot et al. developed a comprehensive FSPM accounting for the interactions between plant architecture, light, soil nitrogen and the metabolism of carbon and nitrogen. The model is evaluated by simulating the functioning of post-anthesis wheat canopies (Triticum aestivum) of contrasting leaf inclination, arranged in pure and mixed stands. As an emergent property of the detailed metabolism, the model predicts single relationships between absorbed light, carbon assimilation and grain mass. Over the post-anthesis period, planophile plants absorb more light than erectophile...

Continue reading FSPM-based investigation of plant interactions in complex wheat canopies

Quercus ilex

Trading food for water – trees exude more carbon under drought stress

Plants secrete carbon compounds into soils through their roots, affecting microbes in such a way that nutrient availability in the soil can increase. This root exudation can cost over 10% of the carbon fixed through photosynthesis, but this cost is thought to be largely offset by the benefits of altering soil microbial activity. Given the amount of carbon that plants can release into soils, root exudation is an important link between the above- and belowground carbon cycling. Despite the importance and magnitude of this process, our understanding of how stresses such as drought affect the amount of exuded carbon is...

Continue reading Trading food for water – trees exude more carbon under drought stress

Tree seedling growth capacity under climate change

Predicting the effects of climate change on tree species and communities is critical for understanding the future state of our forested ecosystems. In a recent study published in AoB PLANTS, Rodgers et al. used a fully factorial precipitation by warming experiment in an old-field ecosystem in the northeastern United States to study the climatic sensitivity of seedlings of six native tree species. Warm and dry conditions suppressed seedling growth, but affected species differently by increasing mortality, enhancing rates of herbivory, or decreasing foliar carbon uptake. Their results indicate that, in the northeastern US, dry years in a future warmer environment...

Continue reading Tree seedling growth capacity under climate change

Epipactis neglecta at forest site 9 in the Nördliche Frankenalb in July 2009

An orchid with a partially mycoheterotrophic taste for truffles

Partially mycoheterotrophic nutrition is a widespread trophic strategy in green-leaved Orchidaceae species in forest habitats. Owing to the light limitation of their habitats, many forest orchids meet carbon demands though autotrophy, and by tapping into the nutritional reserves provided by mycorrhizal fungi. Schiebold et al. analysed the food webs of 12 taxa in the orchid genus Epipactis, obtaining stable isotope natural abundance measurements of Epipactis leaf tissue and fungal sporocarps, and molecular identification of mycorrhizal fungi. The pronounced gradient in 15N enrichment observed in Epipactis species is strongly driven by type and by the 15N abundance of the orchids’ mycorrhizal...

Continue reading An orchid with a partially mycoheterotrophic taste for truffles

New forms of: Carbon, water and photosynthesis

Somewhat disappointingly, this ‘three for the price of one’ item is not about plants – neither exclusively nor even specifically. However, since it deals with matters that are fundamental to all life on Earth (including those green things!), it is certainly admissible in a plant-based blog item. After all, what can be more basic and essential to plant biology than carbon – the basis of organic molecules that constitute the building blocks of construction of the plant body, water – one of the simplest of molecules but which provides the internal structural support for plant bodies, and photosynthesis – the...

Continue reading New forms of: Carbon, water and photosynthesis

Detailed metabolite concentrations for C (left panels) and N (right panels) for two examples of photosynthetic organs

Simulating carbon and nitrogen patterns using an integrated model of wheat functioning

Based on a mechanistic approach, the CN-Wheat model simulates the fluxes of carbon (C) and nitrogen (N) metabolites in wheat plants after anthesis. Barillot et al. show that the CN-Wheat model can be used to predict allocation and dynamics of C and N resources among culm organs in conjunction with observations from field experiments. CN-Wheat also provides insights into how depletion of mobile metabolites caused by grain filling ultimately results in the cessation of resource capture. CN-Wheat appears to be an appropriate model with which to investigate and reveal the myriad functions of integrated plant behaviour.

Continue reading Simulating carbon and nitrogen patterns using an integrated model of wheat functioning

Botanical description of the culm structure of wheat as implemented in the model.

A process-based model of C and N metabolism in the wheat culm

Linking traits and metabolic processes to whole plant performance results in improved crops. Barillot et al., present CN-Wheat, a comprehensive and mechanistic model of carbon (C) and nitrogen (N) metabolism within wheat culms after anthesis. Culm organs are described explicitly and include structural, storage and mobile metabolites. An innovative aspect of CN-Wheat lies in the regulation of physiological processes by metabolite concentration and the environment perceived by the organs, together with the calculation of the balance of primary metabolites. Thus, metabolite concentrations act as the internal variables that allow for integration of multiple processes.

Continue reading A process-based model of C and N metabolism in the wheat culm




Modelling Of Ecosystems: the Cycle, Inputs and Ouputs

Stochastic modelling in ecosystems – progress but we are not there yet

Modelling of processes lets one understand the functions of interacting components, helps to identify parts of processes, and can predict outcomes of changes in the system. Unfortunately, what was a major area of financial modelling is now largely discredited, much to the cost of the rest of us; other areas such as insurance are becoming so constrained by rules and regulation as to be useless. Biological modelling, in contrast is advancing rapidly, whether with respect to subcellular events, whole organism development, or disease epidemiology. This week, Professor Xueron Mao has organized a meeting (previous blog post) at the University of Strathclyde in Glasgow, Scotland,...

Continue reading Stochastic modelling in ecosystems – progress but we are not there yet