Red, far red wavelength, the ratio red to far red, temperature and vegetation at a secondary forest regrowth and under the crowns of three plantation tree species at Umudike, Nigeria.

Abstract

Measurements of temperature, red, far red wavelength of light and the ratio red to far red were made at every 10 minutes interval at marked points along a 15 m transect using thermometers and a Skye 660/730 Radiation Detector and Measuring unit (SKR100: SKR110) at Umudike, Nigeria. Readings were made during the dry and wet seasons under the forest floor of a secondary forest regrowth, under the crowns of Treculia africana, Dacryodes edulis, Irvingia gabonensis and in a 1-year old abandonded farmland. Readings were taken at a height of 50cm above the ground. Plant species within 2.5 X 2.5m 2 quadrats were enumerated every two months. Data revealed that there were variations within and between the red and far red wavelength at the studied sites. The ranges of the far red during the dry season were from-0.30 to 18.77;-0.42 to 10.18;-0.40 to 7.70;-0.60 to 1.36 and-0.39 to 0.31 in abandoned farmland, under the crowns of Treculia africana, Dacryodes edulis, Irvingia gabonensis and a secondary forest regrowth, respectively. The ranges during the wet season were

Species differences in seedling growth and leaf water response to light quality

“…Where studies have compared plant growth response to neutral and filtered light, (Mitchell and Woodward, 1988;Turnbull, 1991), the upper limit of R:FRs used in these trials was in most cases greater than 1.2. However, the range of R:FRs found in the forest understorey and gaps lies between 0.03 and 1.12 (Smith, 1982;Ross et al, 1986) and between 1.7 and 1.8 under a secondary forest regrowth (Dike, 2009) and therefore most of the experiments that have been conducted are of little practical applicability. The influence of R:FR on the leaf water status of forest tree seedlings has implications for seedling tolerance to shade as well as the ability to adjust to elevated light levels associated with forest disturbance.…”