Forest Soils & Site Productivity Soil Organic Matter and Organisms 1

ESRM 410: Forest Soils and Site Productivity The Role of Soil Invertebrates (some of the following slides contributed by J Marra-WA Dept of Agric) (Far Side creator-Gary Larson) 2

Heterotrophic Respiration (Energy Flow) Deciduous Forest Net Primary Production Decomposers 95% Herbivores 5% Invertebrates 10% Microbes Bacteria & Fungi 90% (Richle 1981) (Chemoheterotrophs) Now much research is focused on regulation of nutrient cycling as well as ‘energy flows’ thus revealing organism/environment interaction! 3

SoilProductivity Site and Soil Productivity Comminution - increases surface to volume ratios of litter Innoculation - transport microbial propagules to new substrates Grazing- pruning response increases fungal metabolism - releases nutrients contained in microbial biomass - alters competitive interactions and species composition Mutualism - coevolved interaction in which both microbes and invertebrates benefit Microbial / Invertebrate Interactions in Soil 4

Protozoa Nematodes or roundworms Major groups of Soil Fauna The Microfauna < 0.1 mm 5

Major groups of Soil Fauna The Mesofauna mm Diplura Featherwing beetle Springtails Mites Protura Pseudoscorpions 6

Major groups of Soil Fauna The Macrofauna > 2 mm Ants Ground beetles Millipedes Earthworms Termites Isopods 7

The Earthmovers!! Ants Termites Earthworms Invertebrate Effects on Soil Productivity 8

Earthworms - earthworms+ earthworms 9

Termites: Termitidae Queen Workers and Soldiers 10

Termite mound Fungus farming Termitidae 11

Distance NPP Infiltration rate MoistureBulk Density to mound (m) (g m -2 yr -1 ) (cm h -1 ) (%) (g cm -3 ) Productivity and soil properties in relation to distance to termite mounds. (Arshad 1982) 12

Leaf Cutter Ants: Atta sp. 13

Leaf-cutter Ant Trail Photos by Bob Gara 14

Leaf cutter Ant Defoliation of Pine 15

Excavated fungus garden Vertical distribution of colony 16

North Carolina Puerto Rico Costa Rica Litterbag Study Comparison of Tropical and Temperate Forests (Heneghan et al. 2000) Naphthalene Untreated Percent mass remaining 17

C - without invertebrates F - with invertebrates stems roots in mineral soil roots in humus leaves Birch Seedling Growth (Setala and Huhta1991) 18

► regulating decomposition and nutrient mineralization processes ► stimulate the activity of microbial organisms, ► altering physical properties such as soil structure and porosity ► increase moisture holding capacity of soil. Their effects are generally greater in tropical ecosystems than temperate because of the more moderate climate. Their effects are generally greater in deciduous forests than coniferous because of higher substrate quality. Invertebrates contribute to soil productivity by: 19

Effects of insects and diseases on forest productivity Good or bad? (some of the following slides from Bob Edmonds) 20

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Mountain pine beetle attacks of lodgepole pine in BC. These pictures were taken east of Quesnel about 25 miles last summer (2005). 22

The current host list includes: California black oak, coast live oak, Shreve oak, tanoak, rhododendron, California bay laurel, big leaf maple, madrone, manzanita, huckleberry, California honeysuckle, toyon, California buckeye, California coffeeberry, Douglas-fir and coast redwood and Arrow wood (in Germany, the United Kingdom, and the Netherlands). SUDDEN OAK DEATH An introduced disease? caused by Phytophthora ramorum 23

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Note height growth reduction in infected Douglas-fir trees over 14 year period. Trees were age 24 at beginning of study Mean Cumulative Height Growth (inches) 26

Impact of diseases and insects – good or bad a. Mortality b. Reduced growth c. Destruction of merchantable wood (decay) d. Reduction in pulp yield e. Reduced wood quality - stain f. Delayed regeneration; inadequate stocking (trees/acre) g. Site deterioration - build up of pathogens h. Changes in species succession i. Creation of biodiversity j. Decomposition and nutrient cycling 27

We know that land management practices change the soil community. The link between specific changes and soil function is less clear. Logging and Farming can reduce organic matter in the soil  Reducing tillage tends to result in increased growth of fungi, including mycorrhizal fungi.  Decrease in OM may decrease nutrients, CEC, porosity and water infiltration, ??? Fire may also decrease OM, affect soil organisms, etc (direct, indirect, long & short term) Management affects soil organisms 28

Soil biological crusts are very sensitive to trampling. Biosolids – OM, nutrients, water, … Soil compaction, lack of vegetation, or lack of plant litter covering the soil surface tends to reduce the number of soil arthropods, fungi, bacteria, etc as well as affecting root growth, aeration and water infiltration (EROSION!). Management affects soil organisms 29

SoilProductivity Site and Soil Productivity Physical and Chemical PropertiesBiological Properties soil organic matter soil moisture balance soil structure and porosity nutrient availability soil volume microclimates mycorrhizas nitrogen fixation microbial decomposition invertebrate regulation 30

A well managed soil is a Good Soil A GOOD SOIL is a LIVE SOIL Resilient Soil A LIVE SOIL is a Resilient Soil 31