Changes in Ecological Structure and Function along the Rural-Urban Gradient Urban Ecology Lecture 2

bioticabiotic bioticabiotic "Living organisms ( biotic) and their nonliving ( abiotic) environment are inseparably interrelated and interact upon each other.bioticabiotic trophic structurebiotic diversity material cycles ecosystem trophic structurebiotic diversity material cycles ecosystem Any unit that includes all of the organisms (i.e., the "community") in a given area interacting with the physical environment so that a flow of energy leads to clearly defined trophic structure, biotic diversity, and material cycles (i.e., exchange of materials between living and nonliving parts) within the system is an ecological system or ecosystem."trophic structurebiotic diversity material cyclesecosystem Ecosystem ???

1)The composition of the biological community including species, numbers, biomass, life history and distribution in space of populations. 2)The quantity and distribution of the abiotic (non-living) materials such as nutrients, water, etc. 3)The range, or gradient, of conditions of existence such as temperature, light, etc. Ecosystem Structure

1.The rate of biological energy flow through the ecosystem, that is, the rates of production and the rates of respiration of the populations and the community. 2.The rate of material or nutrient cycling, that is, the biogeochemical cycles. 3.The biological or ecological regulation including both regulation of organisms by environment and regulation of environment by organisms. Ecosystem Function

Origin of Cities Through most of history, the human population has lived a rural lifestyle. Settled communities of people became possible with the advent of agriculture (10,000 to 4,000 BC).

Origin of Cities

Our Study Site – Onondaga Creek It’s urban mouth It’s rural beginnings

Source: reny/papers/Endreny- IJWRD-2004.pdf

BIOMONITORING Key This page was constructed by Allyson Via-Norton, Amy Maher, and Diane HoffmanAllyson Via-NortonAmy Maher All images are copyrighted - Jones & Bartlett Publishers Comments?

Advantage of using the Biotic Index over Chemical Sampling Chemistry is fleeting Bugs integrate the effect of impacts that may not be visible or obvious today Presence or absence of bugs is a good indicator of whether the ecosystem is functioning

For Wednesday’s Lab weeks 1 and 2: Form a team of 4 Decide what you want to measure that you think may change along the gradient and therefore explain the presence or absence of different macro-invertebrates. This is your working hypothesis. Collect bugs Calculate the biotic index and diversity measures such as % EPT. See if you were right!