Respiration of Larch trees

Abstract

Modeling of trees based on whole-plant physiology is a powerful tool to understand function and structure of forest ecosystems (Yoda et al. 1963; Hozumi and Shinozaki 1974; McCree 1983; Sievänen et al. 1988; Hagihara and Hozumi 1991; Mori and Hagihara 1991; Shugart et al. 1992; Watanabe et al. 2004). In particular, whole-plant carbon budget is a sensitive and biologically meaningful indicator to understand plant responses to environmental changes (McCree 1986, 1987; Adams et al. 1990; Gonzàlez-meler and Siedow 1999; Tjokelker et al., 1999). Single-leaf physiology does not predict plant growth and productivity, since individual leaves do not always reflect the physiological behavior of the whole-plant (Sims et al. 1994; Hikosaka et al. 1999). Nevertheless, whole-plant physiological characteristics have been measured only in crops, grasses, horticultural crops, and juvenile trees, whose body sizes are relatively small compared to mature forest trees (Geis 1971; Peters et al. 1974; Reicosky and Peters 1977; Garrity et al. 1984; Meyer et al. 1987; Dutton et al. 1988; Graham 1989; Berard and Thurtell 1990; Bower et al. 1998; Nogués et al., 2001). Because measurement of mature trees requires extensive set-up for controlling temperature and gas exchange, air conditioning units (Meyer et al. 1987) with supply of alternating current are commonly required. However, such a system is generally unavailable in the field in remote areas. In particular, boreal and tropical forests are usually located at remote sites, where elaborate measurement set-up cannot be operated. Therefore, a new system is necessary for measuring the whole-tree respiration with relatively simple equipment.