New User Special Price Expires in

Let's log you in.

Sign in with Facebook


Don't have a StudySoup account? Create one here!


Create a StudySoup account

Be part of our community, it's free to join!

Sign up with Facebook


Create your account
By creating an account you agree to StudySoup's terms and conditions and privacy policy

Already have a StudySoup account? Login here


by: Sallie Lind PhD


Sallie Lind PhD
GPA 3.84

Jerry Franklin

Almost Ready


These notes were just uploaded, and will be ready to view shortly.

Purchase these notes here, or revisit this page.

Either way, we'll remind you when they're ready :)

Preview These Notes for FREE

Get a free preview of these Notes, just enter your email below.

Unlock Preview
Unlock Preview

Preview these materials now for free

Why put in your email? Get access to more of this material and other relevant free materials for your school

View Preview

About this Document

Jerry Franklin
Class Notes
25 ?




Popular in Course

Popular in Environmental Science and Resource Management

This 6 page Class Notes was uploaded by Sallie Lind PhD on Wednesday September 9, 2015. The Class Notes belongs to ESRM 315 at University of Washington taught by Jerry Franklin in Fall. Since its upload, it has received 18 views. For similar materials see /class/192017/esrm-315-university-of-washington in Environmental Science and Resource Management at University of Washington.

Similar to ESRM 315 at UW

Popular in Environmental Science and Resource Management




Report this Material


What is Karma?


Karma is the currency of StudySoup.

You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 09/09/15
ESRM315CFR521 April 18 2008 COARSE WOODY DEBRIS CWD THE IMPORTANCE OF THE DEAD TREE AND ITS DERIVATIVES The importance ofthe dead tree and its derivatives logs and other CWD in the structure and function of forest and aquatic ecosystems has been recognized increasingly as the result of terrestrial and aquatic ecosystem studies over the last 35 years This creates some difficult issues in resource management and utilization and some complex management challenges to insure that appropriate amounts and types of CWD are provided The discovery ofthe importance of the dead tree and downed bole log is perhaps the most challenging ecosystem nding from the standpoint of the traditional forester Life was much easier forthe forester and the engineer when dead trees were viewed as waste fire hazards and impediments and dangers to human beings Snags logs and coarselarge woody debris CWDLWD has functional roles from the forest to the sea Some important references to the roles of CWD are Harmon M E et al 1986 Ecology of coarse woody debris in temperate ecosystems Advances Ecological Research 1 5 133302 Maser Chris Robert F Tarrant James M Trappe and Jerry F Frankin technical editors 1988 From the forest to the sea a story of fallen trees USDA Forest Service General Technical Report PNWGTR229 153 p Functions of Coarse Woody Debris A Terrestrial 1 Habitat for large variety of organisms vertebrates Invertebrates fungi microbes Longterm source of carbon energy and nutrients Site for nitrogen fixation Source of soil organic material unique part of soil matrix Nurse logs for reproduction of other plants Look 01 6 Geomorphic effects influences on downslope movement of soil rock and other materials B Aquatic 1 Structural results in detentionretention of materials water allochthonous inputs etc 2 Habitat a Direct wood itself as habitat for organisms b Indirect creation of additional habitats such as by creation of debrisjams bars pools c Hence provisions for biological diversity niches both directly and indirectly 3 Energy dissipation and armoring of banksshores energy spent through water drops over structures such as log jams and in creating and maintaining plunge pools is NOT available for eroding the streambank or downcutting the stream bed 4 Source of carbon and nutrients a Although wood is NOT an important source of nitrogen it is the site on which Nfixing organisms grow hence important indirectly in the Nbudget ofthe stream b Energynutrients available only slowly 5 Major shifts in locations and functions of CWD depending upon the size ofthe streamriver notion of source and sink areas C Estuarine functions of CWD D MarineOcean functions of CWD Amounts of CWD in forest ecosystems A Measures of the amounts of CWD are mass volume amp B surface area Amounts in typical natural forests including old growth typically 20 of the aboveground organic is in the form of necromass or dead organic matter Much of this is as CWD Wide variation in amounts with the variation associated with different forest types productivity and successional stage Influence of forest types is largely a function of which tree species are present wide variation in decay resistance of wood of different species Influence of productivity is partially a result of environmental conditions moisture and temperature on decay rates D Amount of CWD in relation to successional stage depends very much upon how much dead wood is carried over into the young stands as a biological legacy 1 Best known example CWD following severe disturbance in Douglasfir forest Very high levels of CWD early in succession Most pronounced when measured as the mass of the CWD weightunit area typically metrictonshectare Common pattern 2 Clearcutting dramatically alters the temporal pattern of CWD Dynamics of Coarse Woody Debris A Rates and mechanisms of CWD creation tree death amp disintegration B Questions How mast does it disappear once created What are the processes responsible for the disappearance What are the factors controlling the rates ANSWERS below C Major processes involved in disappearance of CWD are Decomposition Fragmentation and Leaching 1 Decomposition is the process by which organic materials including CWD is biologically burned by other organisms to release energy Results in loss of massunit of wood or reduced wood density 2 Fragmentation is the process by which larger pieces of wood are mechanically broken into smaller and smaller pieces of wood which than no longer qualify as CWD even though the material still exists Important process for snags gravity is pulling down the snags with the help of animals that are mining it and for logs in streams logs are battered as the logs float around a Done by biological or physical agents or both working together b Results in loss of volume c Does not actually consume the wood but does fragment it into smaller pieces by breaking chunks off of it d Invertebrates bore into and fragment wood substrate introducing decay organisms and removing some of the material ingesting andor wasting it e Vertebrates eg woodpeckers and bears often contribute very substantially to fragmentation in their efforts to feed on invertebrates in snags and logs f Gravity provides a big assist to the fragmentation process especially with snags g Fragmentation is the dominant process in aquatic ecosystems 3 Leaching is the process by which materials are removed from a log or snag by being dissolved or suspended in water moving through the structure While this does not remove a lot of mass it can result in substantial removal of some readily dissolved high energy components such as sugars D Major controls on decomposition rates are heartwood chemistry biota and temperature and moisture conditions 1Heartwood chemistry ie the amount and nature of decayresistant chemicals which are in the heartwood is a critical factor in the decay rate of CWD Heartwood may be very decay resistant such as in the case of western redcedar which has many antifungal organic compounds within the heartwood hence its distinctive smell a Decay resistant cedars redwoods sequoias b Moderately decay resistant Douglasfir western larch chestnut lenga c Low decay resistance western hemlock Pacific silver fir red alder 2 All other parts ofthe trees sapwood bark phloem tend to decay at the same rate regardless of species Sapwood and inner bark phloem decay very fast Bark always decomposes very slowly Biota are a critical factor in differences between rate of decay in very wet and very dry environments Influence of moisture and temperature is interactive Fastest decay is under warm moist but not wet conditions 00 A E Some ofthe major differences in rates of decay are a consequence of 1 Snag vs log The relative rates of decay for snags and logs vary in different environments West of the Cascade Range a dead tree of a given size and species will disappear faster if it is standing than if it is down East of the Cascade Range the snag may last as long or longer than the comparable dead tree on the ground 2 Terrestrial vs aquatic A log in aterrestrial environment will decay much fasterthan the similar log in a freshwater stream or pond Freshwater environments lack animal organisms that can penetrate mine a waterlogged log hence decomposition is a very slow process involving the surface mm or the log 3 Streamsrivers vs lakesponds A log in an actively moving body of water will disappear at a much faster rate on average than one is a still body of water This is because fragmentation is such an important process in a moving stream or river 4 Freshwater vs marine Logs disappear much more rapidly in marine saltwater environments because there are many invertebrates which can readily penetrate logs Shipworms for example This niche is NOT lled in freshwater environments Examples of duration of woody debris in marine and freshwater Vassa and Titanic Alvindeposited wood experiments in deep marine floor F Creation of CWD is primarily by the death of trees although it can also be caused by the loss of pieces of trees IV Ontogeny of wood decay in terrestrial environments Changes in density due to decompositiondecay process Changes in volume due to fragmentation Changes in the organisms that are present Changes in wood chemistry especially N Changes in water content longterm and seasonal Contrasts in decay processes among snags logs and suspendedlogs G Contrasts in decay processes between moist coastal regions and dry interior regions nITIUOUJZD V How do we study the process of log decay A Chronsequences B Development of decay classes C Longterm log decomposition experiments


Buy Material

Are you sure you want to buy this material for

25 Karma

Buy Material

BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.


You're already Subscribed!

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

Why people love StudySoup

Bentley McCaw University of Florida

"I was shooting for a perfect 4.0 GPA this semester. Having StudySoup as a study aid was critical to helping me achieve my goal...and I nailed it!"

Kyle Maynard Purdue

"When you're taking detailed notes and trying to help everyone else out in the class, it really helps you learn and understand the I made $280 on my first study guide!"

Steve Martinelli UC Los Angeles

"There's no way I would have passed my Organic Chemistry class this semester without the notes and study guides I got from StudySoup."


"Their 'Elite Notetakers' are making over $1,200/month in sales by creating high quality content that helps their classmates in a time of need."

Become an Elite Notetaker and start selling your notes online!

Refund Policy


All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email


StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here:

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.