No abstract

Abstract:Modern society has undergone a fundamental change to a society built around purposively established organizations. Social theory inthis context can be a guide to social construction. Foundations of SocialTheory is dedicated to this aim. Being oriented towards the design of social institutions it has to choose a voluntaristic, purposive theory of action and must make the behavior of social systems explainable in terms of the combination of individual actions. It has to deal with the emergence and mainten~ce of norms and rights, the concepts of authority, trust, law and legitimacy, the viability of organizations and the efficiency oi social systems. But more important than the specific points is the vision of a new role for social theory in an increas~gly constructed social environment. This vision is the motivation behind Foundations ofSocialTheory.

No abstract

Arid ecosystems, which occupy about 20% of the earth's terrestrial surface area, have been predicted to be one of the most responsive ecosystem types to elevated atmospheric CO2 and associated global climate change. Here we show, using free-air CO2 enrichment (FACE) technology in an intact Mojave Desert ecosystem, that new shoot production of a dominant perennial shrub is doubled by a 50% increase in atmospheric CO2 concentration in a high rainfall year. However, elevated CO2 does not enhance production in a drought year. We also found that above-ground production and seed rain of an invasive annual grass increases more at elevated CO2 than in several species of native annuals. Consequently, elevated CO2 might enhance the long-term success and dominance of exotic annual grasses in the region. This shift in species composition in favour of exotic annual grasses, driven by global change, has the potential to accelerate the fire cycle, reduce biodiversity and alter ecosystem function in the deserts of western North America.

No abstract