The structural complexity, especially canopy and gap structure, of old-growth forests affects the spatial variation of soil respiration (Rs). Without considering this variation, the upscaling of Rs from field measurements to the forest site will be biased. The present study examined responses of Rs to soil temperature (Ts) and water content (W) in canopy and gap areas, developed the best fit mo...

We observed diurnal and seasonal patterns of leaf-scale gas exchange within the crown of a Dipterocarpus sublamellatus Foxw. tree growing in a lowland dipterocarp forest at Pasoh, Peninsular Malaysia. Observations were carried out nine times over 6 years, from September 2002 to December 2007. Observation periods included both wet and mild-dry periods, and natural and saturated photosynthetic ph...

There has been recent and growing interest in applying Cerenkov radiation (CR) for biological applications. Knowledge of the production efficiency and other characteristics of the CR produced by various radionuclides would help in accessing the feasibility of proposed applications and guide the choice of radionuclides. To generate this information we developed models of CR production efficiency...

Fresh pistachio fruit cv. Kalleghochi was harvested from the exterior and interior parts of the tree canopy in four geographical directions. The fruit position in exterior and interior parts of the tree canopy has a significant influence on the number of nuts per ounce, pistachio splitting, hull weight, shell weight, kernel weight, colour indices and total anthocyanin content. Results indicated...

Little is known of the co-occurrence and implications of competitive and facilitative interactions within sites. Here we show spatially disjunct competition and facilitation at forest edges, with beneficial influences of trees on seedling growth via increased ectomycorrhizal infection apparent from 12 to 20 m while closer to trees seedling growth is negatively correlated with canopy closure. As...

Studies on vegetation changes of rangelands under grazed and non-grazedconditions are of great importance in the range management planning programs. To determinethe change process of vegetation, this study was performed in Inche Shorezar site of Golestanprovince for nine years (1997-2005). The vegetation parameters were measured every year inseveral fixed plots inside and adjacent of exclosures...

There is increasing interest in evaluating the environmental effects on crop architectural traits and yield improvement. However, crop models describing the dynamic changes in canopy structure with environmental conditions and the complex interactions between canopy structure, light interception, and dry mass production are only gradually emerging. Using tomato (Solanum lycopersicum L.) as a mo...