We investigated how water and nutrient availability affect radiation-use efficiency (epsilon) and assessed leaf gas exchange as a possible mechanism for shifts in epsilon. We measured aboveground net primary production (ANPP) and annual photosynthetically active radiation (PAR) capture to calculate epsilon as well as leaf-level physiological variables (light-saturated net photosynthesis, Asat; ...

We have developed a reliable procedure for the purification of envelope membranes from cauliflower (Brassica oleracea L.) bud plastids and sycamore (Acer pseudoplatanus L.) cell amyloplasts. After disruption of purified intact plastids, separation of envelope membranes was achieved by centrifugation on a linear sucrose gradient. A membrane fraction, having a density of 1.122 grams per cubic cen...

Ceratocystis fimbriata is a large, diverse complex of species that cause wilt-type diseases of many economically important plants. Previous studies have shown that isolates in three monophyletic lineages within the Latin American clade of C. fimbriata are host-specialized to cacao (Theobroma cacao), sweet potato (Ipomoea batatas) and sycamore (Platanus spp.), respectively. We paired testers of ...

1. The polysaccharide compositions of the cell walls of sycamore cambium and sycamore callus tissue have been analysed and found to be directly comparable. 2. Electrophoretic analyses of the whole pectins prepared from actively growing callus and cambial tissue have shown that these preparations contain, in addition to the neutral and weakly acidic components present in apple fruit, a strongly ...

Results presented in a previous report from this laboratory indicated the presence, in crude extracts from sycamore (Acer pseudoplatanus) and spinach (Spinacea oleracea), of a sucrose synthase (EC 2.4.1.13) showing high affinity for ADP as the glucose acceptor in the sucrose-cleaving reaction. In the present paper we report that the modified enzymatic method previously used to measure sucrose s...

Henneberger, T. S. M., Stevenson, K. L., Britton, K. O., and Chang, C. J. 2004. Distribution of s Xj)lelEu fastidiosn in sycamore associated with low temperature and host resistance. Plant Dis. 88:95 1-958. Experiments were conducted in the field and laboratory to determine effects of low temperatures 4% on Xq'lella fnstidiosa populations in American sycamore. Roots and shoots from naturally in...

Production increases in intensively managed forests have been obtained by improving resource availability through water and nutrient amendments. Increased stem production has been attributed to shifts in growth from roots to shoot, and such shifts would have important implications for belowground carbon sequestration. We examined above and belowground growth and biomass accumulation and distrib...

Over three consecutive years in central Mississippi, sweetgum (Liquidambar styraci/lua L.) and sycamore (Platanus occidentalis L.) fruits had nearly reached fullsize by late June. Sweetgum seeds were physiologically mature by mid-August, but dry weight increased until late September. As sweetgum seeds matured, the crude fat level rose to 27 percent of seed dry weight. During maturation, concent...

Many freshwater ecosystems receive allochthonous resource subsidies from adjacent terrestrial environments. In eastern North American forests, geographic broods of periodical cicadas emerge every 13 to 17 y to breed, and local abundances can sometimes be .300 individuals/m. Most individuals avoid predation, senesce after breeding, and become a resource pulse for forest ecosystems; some cicada c...