Forest maturation

To the extent the current terrestrial sink is a result of regrowth (changes in age structure), the future terrestrial sink is more constrained. First, the net effect of continued land-use change is likely to release carbon, rather than store it. Second, forests that might have accumulated carbon in recent decades (whatever the cause) will cease to function as sinks if they are turned into croplands. Third, the current sink in regrowing forests will diminish as forests mature (Hurtt et al., 2002). 

The density of trees in a forest will decrease as the forest matures. 

H Keith, R. J. Raison, and K. L. Jacobson, Allocation of carbon in a mature eucalypt forest and some effects of soil phosphorus availability. Plant Soil 796 81 (1997). 

Fig. 63. Strychnos axillaris Colebr. Department of Wildlife and National Parks. Plants of Krau. Wildlife Reserve, Malaysia. Field collectors Hanne Christensen and Rozidan M. Geographical localization 3° 36 North-1020 8 East. In mature forest on level ground. 

When nitrogen input owed to mineralization and atmospheric deposition exceeds the demand of both the vegetation and the microbes in undisturbed maturated forest... 

Young trees are hungry for carbon before they mature so one technique is to keep a forest young, by regular thinning. U.S. forests have increased by more than 40% in the last 50 years from 600 billion to nearly 860 billion. Standing timber is increasing at a rate of almost 1% per year in the country. 

The rate of growth of the trees slows as the forest reaches maturity and canopy closure occurs. In addition, the forest eventually establishes equilibrium with the environment, where the rate of carbon sequestration is exactly balanced by the loss of carbon dioxide to the atmosphere due to decay of dead trees and other biomass. 

One experimental tool in this direction is provided by some enveloped animal viruses which mature at the cell surface of infected cells (K Sri inen and Renkonen, 1977 Lenard, 1978). Such viruses include influenza virus, Semliki Forest virus (SFV), Sindbis virus, and vesicular stomatitis virus (VSV). They are extremely simple in makeup and hence are very well characterized. They can be tagged with biochemical probes in many different ways. They infect many animal cells in culture, and after infection turn the cells into factories for the production of virus progeny. The protein-synthesizing machinery of the host cell is programmed by the viral RNA to make viral proteins exclusively and these include the viral surface glycoproteins. These are synthesized with signal peptides and inserted into the ER membrane (Katz et ai, 1977 Garoff et... 

We use trees to meet our paper needs because they are abundant and renewable—for every tree cut down, a new one can be planted. However, growing and harvesting trees has some significant drawbacks. Timber takes decades to mature. This time frame is already not fast enough to keep up with our increasing demand. Also, replanting timber does not re-create a forest. Timber is typically replanted as a monoculture suited primarily for industrial needs. A true forest is a more evolved system of many species that thrive in one another s presence. 

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