Post on 02-Jan-2016
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Terrestrial leaf litter is an important Terrestrial leaf litter is an important nutrient source in streamsnutrient source in streams
Leaf DecompositionLeaf Decomposition
1) Leaves become 1) Leaves become waterlogged and sink. waterlogged and sink. May lose up to 42% May lose up to 42% mass to leaching.mass to leaching.
2) Colonization by 2) Colonization by bacteria and fungi bacteria and fungi begins almost begins almost immediately.immediately.
3) Colonized by shredders (eat CPOM). Shredders convert 3) Colonized by shredders (eat CPOM). Shredders convert CPOM to FPOM. Grazers eat algae and diatoms (FPOM).CPOM to FPOM. Grazers eat algae and diatoms (FPOM).
Leaf DecompositionLeaf Decomposition
Water penny
Crayfish
Cranefly
Amphipod
Snail
Diatoms
4) Collector-gatherers (eat 4) Collector-gatherers (eat FPOM). FPOM).
5) Collector-filterers (eat FPOM). 5) Collector-filterers (eat FPOM). Bacteria and fungi continue to Bacteria and fungi continue to break down CPOM and FPOM.break down CPOM and FPOM.
Leaf DecompositionLeaf Decomposition
MayflyMayfly
Caddisfly
Midge
Black fly
Purpose of this labPurpose of this lab
Question 1: Does presence of Question 1: Does presence of macroinvertebrates accelerate leaf macroinvertebrates accelerate leaf decomposition?decomposition?
Purpose of this labPurpose of this lab Question 2: Do leaves containing Question 2: Do leaves containing
more carbon degrade more slowly? more carbon degrade more slowly? Cellulose and lignin are resistant to Cellulose and lignin are resistant to
decomposition.decomposition.
MethodsMethods
Prepare coarse-mesh maple, coarse-mesh Prepare coarse-mesh maple, coarse-mesh oak, fine-mesh maple, and fine-mesh oak oak, fine-mesh maple, and fine-mesh oak bags.bags.
Place and secure bags in stream/pond.Place and secure bags in stream/pond. Remove bags after ~1 month.Remove bags after ~1 month. Rinse macroinvertebrates from leaves and Rinse macroinvertebrates from leaves and
allow leaves to dry.allow leaves to dry. Weigh and estimate leaf material lost.Weigh and estimate leaf material lost. Count macroinvertebrates and sort Count macroinvertebrates and sort
according to functional feeding groups.according to functional feeding groups.