trees, age 25--30 years, were subjected to two soil-nitrogensupply regimes and to elevated atmospheric CO2 concentrations by the branch-in-bag method from April 15 to September 15 for two or three years. Gas exchange in detached shoots was measured in a diffuse radiation field. Seven parameters associated with photosynthetic performance and two describing stomatal conductance were determined to...

(1) Background: The aim of our study is to present the results initial growth and plant physiology studies newly selected, vegetative propagated black locust clones, with a view assess their suitability for establishment fast growing tree plantations production high quality timber in marginal (semi-arid) sites. (2) Methods: In spring (May) autumn (November) 2021, full inventories were carried o...

This paper deals with the numerical simulation of the diffusion and assimilation by photosynthesis of CO2 within a leaf. An axisymmetric cell centered finite volume scheme is proposed for the discretization of the problem. The resulting code enables the determination of the diffusion coefficient in the leaf porous medium, from experimental measurements of the pointwise value of internal CO2 con...

Heat-waves with higher intensity and frequency and longer durations are expected in the future due to global warming, which could have dramatic impacts in agriculture, economy and ecology. This field study examined how plant responded to heat-stress (HS) treatment at different timing in naturally occurring vegetation. HS treatment (5 days at 40.5°C) were applied to 12 1 m2 plots in restored pra...

Measurements of carbon dioxide and water vapour flux densities were carried out for a grassland area in the centre of the Netherlands during a 12 month continuous experiment using the eddy-covariance technique. Lolium perenne and Poa trivialis mainly dominated the vegetation of the area. The leaf area index (LAI) of the grassland varied between 2.5 and 3.4, depending on the mowing scheme at the...

We examined whether the e€ects of elevated CO2 on growth of 1-year old Populus deltoides saplings was a function of the assimilation responses of particular leaf developmental stages. Saplings were grown for 100 days at ambient (approximately 350 ppm) and elevated (ambient + 200 ppm) CO2 in forced-air greenhouses. Biomass, biomass distribution, growth rates, and leaf initiation and expansion ra...

The effects of H2 gas treatment of an agricultural soil cultivated previously with a mixture of clover (Trifolium pratense) and alfalfa (Medicago sativa) on CO2 dynamics and microbial activity and composition were analyzed. The H2 emission rate of 250 nmol H2 g K1 soil h was similar to the upper limit of estimated H2 amounts emitted from N2 fixing nodules into the surrounding soil ([Dong, Z., L...