recap

Since I started reading months ago, first I will try to quickly summarize what I know to date. Hopefully one day before my comps I will come back to those readings and talk about them more extensively. The topics for my comps are: ECOPHYSIOLOGY, COMMUNITY ECOLOGY, AMPHIBIAN CONSERVATION, STREAM ECOLOGY, and POPULATION BIOLOGY. First, I started reading:

Ecophysiology:
From the book Vertebrate ecophysiology (Bradshaw, 2003):
Chapter 5: Case studies of stress: incidence and intensity. From the book Behavioral approaches to conservation in the wild (Clemmons & Buchholz, 1997) Chapter 6: Conservation and the ontogeny of behavior (McLean) Chapter 11: The importance of social behavior studies for conservation (Komdeur & Deerenberg). As a quick summary: mostly what they talk about how corticosteroids are high when animals are stressed. Immune system is affected by stress…that’s why stressed people get sick. Mc Lean talked about behavioral responses to stress: choosing burrow places, e.g.

Community Ecology:
Null hypotheses in Ecology (Strong) from the Journal Synthese. Talked about how different is Ecology from other “hard” sciences (organismal, lots of different variables, high variability among individuals). Null hypothesis must be explicit in ecology, and most of the time that doesn’t happen at all. Research should be more experimental than observational or corroborative, where they don’t use null hypothesis.

Amphibian conservation:
I am almost finishing the book with that name, edited by Ray Semlitsch. About all the problems that amphibians are facing, and possible solutions. Pond breeding amphibians, N. America stream amphibians, terrestrial salamanders with direct development, amphibians in the new and old world tropics (sad stories: low budget for conservation and research, high treath by unsustainable use of natural resources, endemic unique species, etc, etc), natural population fluctuations and again null models to prove real declines, habitat destruction and alteration, invasive species, pathogens, infectious diseases and immune defenses, ecology and evolution of infectious diseases, effects of pesticides and deformations (I haven’t finish that chapter, so I will post more about it tomorrow).

Stream Ecology:
Principles of Terrestrial Ecosystem Ecology Chapter 12: Community effects on ecosystem processes. Functional types, Abundance effects on ecosystems (Keystone species). Effects on resources (e.g. nitrogen fixing tree-Myrica), climate, disturbance regime, mutualism, top-down controls, diversity in functional types enhances efficiency of resource use and retention and stabilizes ecosystem processes, temporal variations, complementary use of resources.

Stream Ecology: Structure and Function of running waters
Chapter 2: Streamwater chemistry: determinants of riverwater chemistry: geology, rainwater, volcanic activity, pollution. Materials in river: Dissolved & Suspended; Organic & Inorganic. Dissolved gases: O2 y CO2. CO2 more soluble in water than O2. Concentrations change seasonally and daily. O2 higher in cold waters. High rainfall and runoff have less concentrated waters. Groundwater is more concentrated and has less O2 than surface water, and is less variable.
More CO2, less pH. Hardness relates to Mg and Ca concentration. Number of species commonly increases with hardness. Water of low ionic concentration support fewer fauna.
Chapter 3: physical factors of importance to the biota.
Current: physical adaptations, flow (laminar, transitional, turbulent), behavior, equations to describe streamflow (Re: UL/v= Bulk flow, Reynolds number).
Substrate: inorganic, organic, importance of detritus (more spp), Lithophilus (stones), psammophilus (sand), xhylophilus (wood), phytophylus (plants). Higher abundance in detritus, leaves, and cobbles.
Temperature: in small streams shading can alter summer temp. Stenothermal (narrow temp range animals), Eurythermal (wide range). Less temp, less 02, restricts organisms. Temp triggers development, influences egg developmental rate, juvenile growth, productivity. Less temp, high body mass (insects)
Oxygen: current influences 02, some animals have behaviors to have more O2 in slow moving waters or high temp.

That’s it for today…from tomorrow I will try to summarize less and write a little every day.