Effect of Gap Sizes on Specific Leaf Area and Chlorophyll Contents at the Castanopsis kawakamii Natural Reserve Forest, China

Abstract

The two hemispherical photographs (THP) method was used to calculate gap area. The areas of nine forest gaps were measured. Meanwhile, non-gap areas were selected as control groups with areas of 225 m2. Plots with areas of 25 m2 in five different directions within gap and non-gap areas were conducted for collecting leaf samples. To determine the effect of gap size on leaf traits the selected traits were leaf area (LA), leaf dry mass (LDM), specific leaf area (SLA), Chlorophyll a (Chl a), chlorophyll b (Chl b), total chlorophyll (TChl), and carotenoid (CAR). Leaves were collected from the regeneration layer (<2 cm DBH, height 2–5 m) to measure the leaf traits in winter and summer seasons. Results confirmed significant positive correlations between LA and LDM in the small, medium, large gap sizes, and non-gap areas (r2 = 0.913, 0.827, 0.897, and 0.939, p < 0.01, respectively). On the contrary, relationships between LDM and SLA in the small, medium, large gap sizes, and non-gap areas have significant negative correlations (r2 = −0.269, −0.259, −0.417, and −0.505, p < 0.05, respectively). The effect of gap size on the average Chl a, Chl b, TChl, and CAR varies by the season. During the summer season, the highest chlorophyll contents were recorded in the small gap size and the lowest in the non-gap area, while during the winter season, the highest values of these chlorophyll contents appeared in the medium gap size. Moreover, the directions within the gap in the medium gap size of the summer season had an effect on the Chl a and TChl.

The Spatial Variability of Soil Physical Properties of Different Sized-gap in a Subtropical Forest, China

“…Combining the three parameters that describe soil composition, we found that gap size improved it, with soil in canopy gaps having a low bulk density and high-water content, especially in the small and large gaps, when compared with the areas under the canopy. Moreover, the results about the effect of light on the variety of microenvironment in the gap reported that the microenvironment in gap areas vary more than under canopy areas which support the species growth [20]. Plant growth depends on soil composition.…”

“…Organic matter is the main source of nutrients for the plant growth which decomposed from organic material by the microbial activity in soil [30]. The mechanisms that made the large gap size has a high amount of organic matter due to the large gap size provides high light intensity through the forest floor [20]. This high temperature of the forest floor generates the organic matter decomposition lead to high soil organic matter.…”

“…Total rainfall per year is about 1,500 mm (data was averaged of 40 years (1972-2012) collected by the Sanming Climatological Bureau, China). Humus and soil nutrients are concentrated in the top 1 m layer of the soil [20].…”

Impacto del fuego en la defensa de las plantas: Rasgos funcionales y síntesis de metabolitos secundarios en especies leñosas del Chaco semiárido de Argentina

“…Sin embargo, la correlación negativa entre AFE y CAF con el tamaño de la planta, podría atribuirse al hecho de que las hojas en plantas de mayor tamaño reciben mayor radiación y experimentan niveles de desecación acentuados al elevarse con respecto al nivel del suelo, evento más pronunciado aún, en ambientes con sequías prolongadas (Kenzo et al, 2015). De hecho, el AFE es considerado como el rasgo funcional más relacionado con el crecimiento de la planta (Buajan, Liu, He, y Feng, 2018).…”

“…Aunque las clorofilas son el principal pigmento fotosintético, ya que se encargan de capturar la energía lumínica y transformarla en energía química para el desarrollo de la estructura vegetal, los carotenoides cumplen un rol importante en este proceso, ya que capturan la luz solar y la transfieren a las clorofilas para que éstas la metabolicen (Cambrón-Sandoval et al, 2011). Además, estos compuestos cumplen una función antioxidante que le otorga protección a las clorofilas de los radicales libres, que podrían destruir el aparato fotosintético (Buajan et al, 2018). Los pigmentos fotosintéticos en conjunto son muy sensibles a las variaciones ambientales, lo que explica la pérdida de la capacidad fotosintética que experimentan las plantas sometidas a cualquier tipo de estrés (Carter y Knapp, 2001).…”