Topics for quiz: Scale of ecosystems Succession (Indiana dunes, Pacific northwest…) Habitat/Niches Characteristics of old growth Scientific Forestry vs. New Forestry Carbon Accumulation in forests Nitrogen cycling in ecosystems Types of interactions: mutualism, commensalisms etc… Role of dead wood in the ecosystem Mycorhyzae, symbiosis in the forest Epiphytes and Endophytes Role of insects Soil structure/texture

Alder Snowberry Lichen Chapter 5 from Hicks, William T. 2000. Modeling nitrogen fixation in dead wood. Corvallis, OR: Oregon State University. 160 p. Ph.D. dissertation

Luoma 5 Coarse woody debris—large pieces, not litter, mostly dead wood Litter—small pieces, quick to be recycled 5 tons per acre per year -what does that look like?

Figure it out now 1 ton = 2000 lbs 1 acre = 43560 ft2 1 ft = 12 inches Density of soil: 1 ft3 = 50 lbs 5 tons per acre per year is how many inches per square foot per year?

Luoma 5 living tree has ~5% living cells Harpaphe hydeniana Luoma 5 living tree has ~5% living cells “dead” wood or downed tree ~ 20% living cells, 219 tons/acre = ¼ of the forest floor covered.

Luoma 5: What functions does dead wood play in the forest?

Luoma 5: What functions does dead wood play in the forest? Forest service’s 3 stages: Hard snag: holes must be made, water, fungus, insects, animals move in Soft snag: Habitat for insect larvae-->food for birds, holes become nesting sites, some birds and mammals will only nest in snags with holes made by previous residents Buckskin snag has lost its bark and begins to fall apart, higher availability of carbon, adds woody material to the forest floor that holds and slowly releases moisture and adds nutrients

Movie time

Luoma 6: Soil Structure What is soil structure? What does it include? Why is it important? physical chemical energy biological

Luoma 6 Soil as a biological consortium (or environmental system) vs. inorganic material.

10% clay, 50% sand…

Soil Structure Physical structure What do plants get from the soil?

10% clay, 50% sand…

Soil Physical Structure cont. differ within a profile, soil horizons Soil Profile

Soil Structure Chemical structure -- What nutrients are in soil besides nitrogen and carbon? Phosphorous, sulfur, calcium, potassium, sodium, and metal salts. Where are the nutrients? Calcium (Ca) feldspar Potassium (K) feldspar

Soil Structure Energy structure – temperature, absorption/reflection of light=heat, heat sink Biologic structure – Andy Moldenke = complexity, root zone, arthropods Munsell Soil Color Chart Gleyed Soil Mottle with Root Channels

Luoma 6 What is BPGT? How does Bug Poop Grow Trees? Arthropods as key shredders Sow bugs & sulfur Keystone insects? Harpaphe millipede is a shredder Oribatid mites--sheer volume and speed are very important. Hyphae—fungi thread mycorrhizae

CLORPT Why is the soil structure the way it is? How are those components distributed? CLORPT--Five soil forming factors influence the type of soil CLimate Organic material or organisms Relief Parent material Time

CLORPT

CLORPT Organic matter or organisms (O) helps determine: water holding capacity rates of nutrient cycling and availability

CLORPT Relief (R) helps determine: soil profile thickness: thickness of the A horizon varies with slope position soil fertility--Compare the crest, slope face, and slope base for soil fertility.  Where would you expect soils to be most fertile? 

CLORPT Parent material (P) helps determine: soil texture –sandstone vs. shale rates of soil formation minerals as a nutrient source. The primary soil nutrients are N, P, K, Ca, Mg, and S

CLORPT Time (T) helps determine: soil horizon

Passive vs Active Transport Osmosis

Siderophores chemicals released by fungi and bacteria that help bind iron or other metals (through chelation) into a form that is usable by plants.

Soil science: Scavenging for scrap metal Benjamin D. Duval & Bruce A Soil science: Scavenging for scrap metal Benjamin D. Duval & Bruce A. Hungate, Nature Geoscience 1, 213 - 214 (2008) Under metal-limiting conditions, the bacterium A. vinelandii secretes metal-scavenging compounds (siderophores; S) (1). These siderophores scavenge the metals molybdenum and vanadium from unavailable complexes with clay, soil organic matter or other elements (2). The siderophores compete with siderophores produced by other organisms such as fungi for these metals (3). The bacterium or plant roots readily take up the siderophore-metal complexes (4). Within the bacterium, the metal is incorporated into the enzyme nitrogenase (5), to allow the fixation of atmospheric nitrogen (N2) that would otherwise be unusable to the bacterium.

How does Mycorrhizal symbiosis help the tree? Surface area of hyphae is 1000x greater than roots alone. Water availability. They protect trees from bacterial infestation by releasing chemicals that kill bacteria (antibiotics). They also release hormones that stimulate root branching. Allows trees to grow in places that they never could without the symbiosis ex. Hyphal bridge & shade. Also Acid mine tailings can support trees with acid protective fungi. (Acid Rain-acid mobilizes metals and changes soil pH. Some fungi help trees survive, while others can’t. Produced by air pollution.) Exude enzymes for decomposition of organic debris that is among the toughest to break down. Lignin, release of N from organically bound forms

What do the fungi get out of it? 40% of the sugars produced by a tree are released into the soil to be consumed by fungi and whomever else is around. Factoid: Fungi is about 50% of the total biomass in the soil (which contains roots!) where thickest and cover ¼ of the forest floor.

Observation – movie time!