Saturday, April 21, 2007

The carbon cycle and ecosystems, the biosphere an “appendage of the atmosphere”

The “gases of the entire atmosphere are in a state of dynamic and perpetual exchange with living matter”.

Vernadsky The Biosphere

The information about atmospheric warming imparts particular significance to the task of determining the real-life dynamics of the biosphere. The actual contributions of the land and ocean biota’s have not been accurately determined, although there is a great body of literature on the subject.

Indeed both quantification and qualification of the “carbon cycle” has been handled badly by the UNFCC and WCRP. With simplistic assumptions and generalized parameters that are formatted by “climate scientists “with little understanding of the interconnected and overlapping oscillations of dynamic energy exchangers in a state of self organization

“Even at these places, sampled in the free atmosphere, the concentrations and carbon isotopic ratios were nearly the same as in the afternoon near vegetation (30, 32). Why didn’t photosynthesis, which takes CO2 out of the air during the day, cause low and variable concentrations when respiration by plants and soil, which puts CO2 into the air at night, causes high and variable concentrations? I found an explanation in a book that attracted my attention because of its apt title: The Climate Near the Ground (21). All of my forest measurements had been made during fair weather. On such days heating by the Sun typically induces enough turbulence in air near plants to cause thorough mixing of this air with the free atmosphere by early afternoon. Where I had sampled, the free air evidently had been of nearly constant composition with respect to CO2. In contrast, during the nighttime the air near the ground cooled, forming a stable layer that allowed CO2 from respiration to build up within the forest canopy.”

Charles Keeling autobiography

The extensive scientific discussion of global warming causes a natural wish to relate this process to possible changes in the amount and dynamics of terrestrial and oceanic vegetation. Does this process influence variations in the amount and diversity of plants or metabolic oscillation? Plausible yes from a metrological perspective. However this is a subset of the total ecosystem and has less importance then either biogeochemical, or biologic parameters

First let’s define self organization; we will use Francis Heylighen’s description,

Self-organization can be defined as the spontaneous creation of a globally coherent pattern out of local interactions. Because of its distributed character, this organization tends to be robust, resisting perturbations. The dynamics of a self-organizing system is typically non-linear, because of circular or feedback relations between the components. Positive feedback leads to an explosive growth, which ends when all components have been absorbed into the new configuration, leaving the system in a stable, negative feedback state. Non-linear systems have in general several stable states, and this number tends to increase (bifurcate) as an increasing input of energy pushes the system farther from its thermodynamic equilibrium. To adapt to a changing environment, the system needs a variety of stable states that is large enough to react to all perturbations but not so large as to make its evolution uncontrollably chaotic. The most adequate states are selected according to their fitness, either directly by the environment, or by subsystems that have adapted to the environment at an earlier stage. Formally, the basic mechanism underlying self-organization is the (often noise-driven) variation which explores different regions in the system’s state space until it enters an attractor. This precludes further variation outside the attractor, and thus restricts the freedom of the system’s components to behave independently. This is equivalent to the increase of coherence, or decrease of statistical entropy, that defines self organization.

Does it influence the pattern of their seasonal and long-term variations? Of particular importance is the problem of determining the dynamics of primary production. The changes are of different scales in space and time.

To determine the relationship between global changes in climate and the biosphere, it is particularly important to trace long-term variability of biological parameters at different latitudes and in different biogeographic conditions. Scaling is important. As is the observable changes in phenotype and genetic evolution which is measurable over several generations in the microbial world and at decadal level in pastures. It is called adaptation and evolution.

An interesting paper that identifies differentials in spatial and temporal variances in meteorological/biologic parameters has been published by van der Tol1, et al Biogeosciences, 4, 137–154, 2007.

Abstract. The aim of this study is to explain topography induced spatial variations in the diurnal cycles of assimilation and latent heat of Mediterranean forest. Spatial variations of the fluxes are caused by variations in weather conditions and in vegetation characteristics. Weather conditions reflect short-term effects of climate, whereas vegetation characteristics, through adaptation and acclimation, long-term effects of climate. In this study measurement of plant physiology and weather conditions are used to explain observed differences in the fluxes. A model is used to study which part of the differences in the fluxes is caused by weather conditions and which part by vegetation characteristics.

The model predicted diurnal cycles of transpiration and stomatal conductance,
both their magnitudes and differences in afternoon stomatal closure between slopes of different aspect within the confidence interval of the validation data. Weather conditions mainly responsible for the shape of the diurnal cycles ,and vegetation parameters for the magnitude of the fluxes. Although the data do not allow for a quantification of the two effects, the differences in vegetation parameters and weather among the plots and the sensitivity of the fluxes to them suggest that the diurnal cycles were more strongly affected by spatial variations in vegetation parameters than by meteorological variables. This indicates that topography induced variations in vegetation parameters are of equal importance to the fluxes as topography induced variations in radiation,humidity and temperature.


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