SOLUBLE SUGAR COMPOSITION OF POND‐CYPRESS: A POTENTIAL HYDROECOLOGICAL INDICATOR OF GROUND WATER PERTURBATIONS¹

Abstract

Pond-cypress, a deciduous conifer, is a dominant canopy species in depressional wetlands of the southeastern Coastal Plain (SCP). Extensive premature decline and death of pond-cypress trees in central Florida have been attributed to hydroperiod alterations due to excessive withdrawals of ground water from the Floridan aquifer. One factor identified in the decline process is basal decay, which may be related to the presence of Botryosphaeria rhodina and Fusarium species (nonaggressive, facultative fungal pathogens). These fungi have been cultured from sapwood tissue of declining pond-cypress associated with ground water mining, but not from pond-cypress away from ground water mimng areas. In this experiment, differences in soluble (nonstructural) carbohydrate composition of branch tips were evaluated for one-and two-year old, nursery-grown (unsheltered) pond-cypress, following a year of growth under treatment conditions (control, fungal inoculation, water stress, and fungal inoculation plus water stress) in a growth chamber. Results from two methods of wet chemical analysis were compared (trimethylsilyl methylglycoside -Method A, and alditol acetate -Method B). Three pentoses (arabinose, rhamnose, and xylose) and three hexoses (galactose, glucose, and mannose) were identified in branch tips from both age classes. A fourth hexose (fucose) also was identified in samples from the younger trees. The acidic sugar, galacturonic acid, was identified in both age classes using Method A. Results suggest that prolonged water stress is correlated with greater relative concentrations of the neutral soluble sugars rhamnose (P = 0.02), xylose (P = 0.02), and galactose (P = 0.02), in addition to the acidic sugar galacturonic acid (P = 0.01), for Method A, and arabinose (P = 0.02) for Method B. These results also suggest that in the absence of water stress, the fungal pathogen B. rhodina does not penetrate to the sapwood of the trees, and that inoculation with this fungal pathogen is not correlated with differences in relative concentrations of nonstructural, soluble carbohydrates, based on Method A analysis. Empirioccurred (Bacchus, 1994;1999; unpublished data). In 'Paper No.

Effect of Water Deficit on Gas Exchange, Osmotic Solutes, Leaf Abscission, and Growth of Four Birch Genotypes (Betula L.) Under a Controlled Environment

“…The most abundant carbohydrates detected in leaves of the four genotypes were glucose, fructose, and sucrose, which was in accord with Mononen et al (2004). The water-deficit-induced increase in total foliar carbohydrates, polyols, and organic acids has been reported as an indicator of osmotic adjustment during water-deficit stress in many woody and herbaceous species (Arndt et al, 2001;Bacchus et al, 2000;Malinowski and Belesky, 2000;Pankovic et al, 1999;Patonnier et al, 1999;Richardson et al, 1992). Osmotic adjustment could help maintain plant turgor and facilitate physiological activities (Hare et al, 1998;Malinowski and Belesky, 2000), which was not previously observed in birch genotypes in response to imposed water deficit (Ranney et al, 1991).…”

Near‐infrared spectroscopy of a hydroecological indicator: new tool for determining sustainable yield for Floridan aquifer system

“…The preliminary research on young pond-cypress trees by Bacchus et al (2000;see also Bacchus et al, in review) suggests that spectral analysis of pond-cypress branch tips using the NIRSystems  6500 can provide a more scientifically-based and sensitive means of detecting responses to groundwater perturbations than the current approaches. Spectral analysis of pond-cypress from natural stands has not been reported previously.…”

“…As a first step to developing a new approach for early detection of stress from prolonged water deficits, Bacchus et al (2000) evaluated differences in composition of non-structural soluble sugars in branch tips from young pond-cypress subjected to controlled water stress conditions in a growth chamber experiment. An annual cycle of temperature, humidity and day length was simulated for the central Florida area where the trees originated.…”

Mapped Fractures and Sinkholes in the Coastal Plain of Florida and Georgia to Infer Environmental Impacts from Aquifer Storage and Recovery (ASR) and Supply Wells in the Regional Karst Floridan Aquifer System

“…Examples of adverse environmental impacts throughout the extent of the FAS associated with pirated water from aquifer withdrawals (mechanical and nonmechanical) and injections, including ASR, have been described by Bacchus (1998;2001;2002;2006;2007); Bacchus and Barile (2005); Bacchus and Brook (1996); Bacchus et al (2000;2011;2015a Sonenshein and Hofstetter (1990);and Wilcox, Solo-Gabriele, and Sternberg (2004). This large body of literature has identified many categories of adverse impacts.…”

“…The irreversible degradation of habitat leads to declines in native wildlife (Bacchus, 2000). Examples of these and other adverse environmental impacts in the FAS are described in Bacchus (1998;2001;2006;2007) and Bacchus et al (2000;2011;2015a Table 5 were identified in the 2015 SWAP as particularly relevant to aquatic species.…”