Early life on land and the first terrestrial ecosystems

Early life on land and the first terrestrial ecosystems

Terrestrial ecosystems have been largely regarded as plant-dominated land surfaces, with the earliest records appearing in the early Phanerozoic (<550 Ma). Yet the presence of biological components in pre-Phanerozoic rocks, in habitats as different as soils, peats, ponds, lakes, streams, and dune fields, implies a much earlier type of terrestrial ecosystems. Microbes were abundant by ~3,500 Ma ...

Biomass turnover time in terrestrial ecosystems halved by land use

“the effect of risk aversion on the demand for life insurance: the case of iranian life insurance market”

abstract: about 60% of total premium of insurance industry is pertained?to life policies in the world; while the life insurance total premium in iran is less than 6% of total premium in insurance industry in 2008 (sigma, no 3/2009). among the reasons that discourage the life insurance industry is the problem of adverse selection. adverse selection theory describes a situation where the inf...

Effects of Land-Use Change on the Carbon Balance of Terrestrial Ecosystems

Most changes in land use affect the amount of carbon held in vegetation and soil, thereby, either releasing carbon dioxide (a greenhouse gas) to, or removing it from, the atmosphere. The greatest fluxes of carbon result from conversion of forests to open lands (and vice versa). Model-based estimates of the flux of carbon attributable to land-use change are highly variable, however, largely as a...

Terrestrial Ecosystems and Their Change

P.Ya. Groisman and G. Gutman (eds.), Regional Environmental Changes in Siberia and Their Global Consequences, Springer Environmental Science and Engineering, DOI 10.1007/978-94-007-4569-8_6, © Springer Science+Business Media Dordrecht 2013 Abstract This chapter considers the current state of Siberian terrestrial ecosystems, their spatial distribution, and major biometric characteristics. Ongoin...