The Ecology of Catskill Headwaters: "The Search for criticality" focuses on the complex dynamics of the riparian, benthic and hyporhiac (sic) zones of headwater streams in the Catskill Mountains. Organisms that inhabit these zones live in constant contact with water and are potentially the most sensitive indicators of declining ecosystem health as a result of changes in water quality. These complex adaptive systems are buffered to some extent from the effects of change in important biogeochemical elements.

The study of complex adaptive systems, like a coevolving ecosystem, has lead to the concept of criticality. In large interactive systems - dynamical systems - there is a natural evolution to a critical state. These systems that have reached this critical state share a characteristic property. If such a system is agitated you may get a small response. Agitate it again with the same degree of disturbance and it may collapse completely. Agitate it many times while poised at the critical state and you get a range of responses. Big responses will be rare, small responses common, and intermediate responses in between.

• Define baseline variation, over time and space, in the species composition and richness of indicator organisms inhabiting the headwater streams in the Catskill region.
• Monitor changes in water quality in headwater streams as it relates to species composition and richness of indication organisms. [pH, dissolved oxygen, nitrates, phosphates, alkalinity, conductivity]
• Monitor changes in the species composition and richness of indicator organisms.

• A suite of ground beetles (Coleoptera: Carabidae) inhabit the splash zone of streams. These beetles are diverse, abundant, taxonomically well known, highly sensitive to habitat change, and opportunistic feeders.
• Two closely-related species of Dusky salamander also inhabit the splash zone, living under rocks. Because amphibians must keep their skin wet, they are sensitive to changes in water quality.
• Immature Tricoptera (Caddisfly larvae) are an important element of the benthic macroinvertebrate community frequently sampled to assess water quality. We are studying the adults to confirm species-level identification.

Benthic Zone - the habitat on the bottom of freshwater streams:

The invertebrate organisms that can be observed with the un-aided eye [macroivertebrates] have been established as useful indicators of water quality. We are participating with the Hudson Basin River Watch (HBRW) who have organized a network of citizen and student volunteersto monitor the entire Hudson River watershed.

• We have set up a long-term monitoring program in four headwater streams in each of the five major watersheds in the Catskill region (the East Branch Delaware River, Esopus Creek, Neversink River, Schoharie Creek, and the West Branch Delaware River).
• We have set up a service laboratory to support community stream monitoring in the Catskill region. This laboratory does species-level determinations of macroinvertebrates as needed to calculate indexes of water quality.

• We will study the fauna of this zone in rocky headwater streams that dry-up in summer.

The range of natural vegetation in time and space of the composition and abundance of Carabidae communities is not known, however our previous studies have established that the regional pool of Carabidae living in the riparian zone of Catskill watercourses contains at least forty-one (41) species. Our preliminary data support the trend of increasing species richness on streams of increasing size. Further, we have established that there is little overlap between the species living in headwater streams with species living in higher order streams. Each time a collection is made, water is collected to measure pH, nitrates, and other water quality parameters.