Despite these issues, many ecologists and conservation biologists are pursuing ecosystem valuation. A cooperative approach to reintroduction by ecologists and biologists could improve research techniques. Population ecologists should therefore collaborate with biologists, ecologists, and wildlife management to improve reintroduction programs. Most were ecosystem ecologists or mainstream environmental economists, with the exception of Daly. In practice, there is considerable overlap between the work of ecologists and other environmental scientists. Paleotempestology information is further of interest to archeologists, ecologists, and forest and water resource managers. These include; animal liberationists, anti-capitalists, green anarchists, deep ecologists, eco-feminists, and anti-globalisationists. Whittaker proposed several ways of quantifying differentiation, and subsequent generations of ecologists have invented more. This is what ecologists call the first trophic level. Allelopathy is not universally accepted among ecologists. Lack of major political allies for these ecologists explained this failure to take any seats. These plans were the subject of criticism by various ecologists. This has been referred to as ecologists 'selling out on Nature'. Lawyer Digna Ochoa was murdered in 2001 while pursuing legal rights for peasant ecologists. Koh is one of the most highly cited Singaporean ecologists.