Chapter 8 Woody Detritus Mass and its Contribution to Carbon Dynamics of Old-Growth Forests: the Temporal Context Mark E. Harmon Woody detritus is an important component of forested ecosystems. It can reduce erosion and affects soil development, stores nutrients and water | Chapter 8 Woody Detritus Mass and its Contribution to Carbon Dynamics of Old-Growth Forests the Temporal Context Mark E. Harmon Introduction Woody detritus is an important component of forested ecosystems. It can reduce erosion and affects soil development stores nutrients and water provides a major source of energy and nutrients and serves as a seedbed for plants and as a major habitat for decomposers and heterotrophs Ausmus 1977 Harmon et al. 1986 Franklin et al. 1987 Kirby and Drake 1993 Samuelsson et al. 1994 McMinn and Crossley 1996 McCombe and Lindenmayer 1999 . Woody detritus also plays an important role in controlling carbon dynamics of forests during succession. Along with live woody parts of trees dead wood or woody detritus is a large pool undergoing a relatively large change in stores during succession Davis et al. 2003 . In contrast carbon in the mineral soils represents a large store but generally changes slowly see Chaps. 11 Gleixner et al. and 12 Reichstein et al. this volume . Moreover the organic layer lying above the mineral soil can change very rapidly but generally represents a small proportion of total forest carbon stores. Woody detritus takes many forms. Fine woody detritus FWD with the exception of roots is typically less than 10 cm in diameter the former being based on lag-times of fire fuels. For woody roots the size break is usually 2 mm which is based on conventions on the maximum size of live fine roots. Coarse woody detritus CWD exceeds these diameters usually cm but also typically must exceed a length of 1 m. Woody detritus is present in the form of roots stumps branches including attached dead branches standing dead . snags and downed material. Very few inventories measure all these forms and size classes standing and downed dead material being the most commonly measured. This chapter reviews what is known about how aboveground woody detritus mass changes over forest succession. To understand the quantity and quality
