What factors limit ecosystem evolution? Like human economies, ecosystems are arenas where agents compete for locally limiting resources. Like economies, but unlike genes, ecosystems are not units of selection. In both economies and ecosystems, productivity, diversity of occupations or species and intensity of competition presuppose interdependence among many different agents. In both, competiti...

There is little published information on "nearnatural" ecosystems and their restoration. Ecosystem restoration involves the setting of a date to indicate a restoration point (e.g., 1778 for the National Park Service in Hawaii) and presupposes some knowledge of ecosystem status at the target date and time. In Hawaii, knowledge of past conditions is usually precluded by the rapidity and magnitude...

Recent studies of the relationship between biodiversity and functioning in marine ecosystems have yielded non-saturating patterns that contrast sharply with the results of experimental studies, where ecosystem functioning rapidly saturates with increases in biodiversity. Here we provide a simple theoretical framework of three alternative hypotheses that, individually or combined, are likely to ...

A declining rate of recovery following disturbance has been proposed as an important early warning for impending tipping points in complex systems. Despite extensive theoretical and laboratory studies, this 'critical slowing down' remains largely untested in the complex settings of real-world ecosystems. Here, we provide both observational and experimental support of critical slowing down along...

The speakers in this session dealt with practical and philosophical approaches to the protection and management of Hawaiian ecosystems. Problems in monitoring and restoring ecosystems were considered; allowances for fundamental natural processes such as succession, cohort senescence, gene transfer and bottlenecks, and natural selection were discussed; and the immense problem of preserve design ...

Fundamental laws govern all complex flow systems, including natural ecosystems, economic and financial systems. Natural ecosystems are practical exemplars of sustainability: enduring, vital, adaptive. The sustainability of any complex flow system can be measured with a single metric as an emergent property of its structural diversity and interconnectivity; it requires a balance in emphasis betw...

Three types of evidence suggest that natural ecosystems are organized for high productivity and diversity: (i) changes not previously experienced by a natural ecosystem, such as novel human disturbances, tend to diminish its productivity and/or diversity, just as 'random' changes in a machine designed for a function usually impair its execution of that function; (ii) humans strive to recreate p...

natural ecosystems provide many goods and services for human beings via their multiple functionalities. one of these important functions is the role of natural ecosystems in regulation of hydrologic cycle and increasing the infiltarion and retention of water in soil context and preventing from water runoff which may cause in unfavorable consequences like soil erosion and flooding. quantificatio...