TITLE PAGE - acumen - The University of Alabama

100% organic matter (i.e., maximum amount of organic carbon directly consumed) or 100%
macroinvertebrates (i.e., minimum amount of organic carbon directly consumed). Demand was
estimated by dividing the annual production of O. australis by the product of diet-specific (e.g.
organic matter or macroinvertebrate) assimilation efficiency (AE) and net production efficiency
(NPE; Benke & Wallace, 1980). Estimates of AE and NPE were acquired from the literature for
both surface and cave crayfish fed diets similar to those found in natural habitats (e.g. organic
matter or macroinvertebrates; Table 2).
Resource supply rate (g m -2 yr -1 ) was estimated assuming that i) the standing crops of
organic matter and macroinvertebrate biomass did not vary through time and ii) that the
resources incorporated (e.g., consumption and assimilation) into consumer biomass or lost
through respiration or downstream export are replaced (i.e., steady state conditions). These
assumptions appear to be valid given the low amount of variation in monthly estimates of
organic matter and macroinvertebrate biomass reported for three cave sites in Venarsky et al.
(2012a) and Chapter 3 of this dissertation.
During the processing of core samples, standing crop organic matter was not partitioned
into different categories (e.g. wood or leaves). Thus, minimum and maximum annual organic
matter supply rates were estimated by assuming that all organic matter was either leaf-litter (e.g.
maximum supply rate) or wood (e.g. minimum supply rate). Organic matter supply rate was then
estimated as the product of mean annual organic matter biomass and average annual breakdown
rate of leaf-litter or wood. Breakdown rates of leaves and wood were acquired from the literature
(Table 1). Breakdown rates for leaves were from cave streams (Table 1) and wood rates were
from surface and cave streams. Annual secondary production of macroinvertebrates was
108