Microclimatic conditions determined by stem density influence leaf anatomy and leaf physiology of beech (Fagus sylvatica L.) growing within stands that naturally regenerate from clear-cutting

Abstract

Beech forests naturally regenerating from clear-cutting can exhibit different microclimates depending on size of saplings and stem density. When beech trees are young and stem density is low, the level of radiation inside the ecosystem reaching the soil surface is high; consequently, air and soil temperatures rise and the soil water content may decrease. These microclimatic parameters presumably will affect the anatomy, photosynthesis, and carbon metabolism of beech leaves. We studied the morphology and physiology of sun and shade leaves of beech trees differing in age and growing within clear-cut areas with distinct microclimate. Results were compared with those of adult trees in an unmanaged forest. We selected a stand clear-cut in 2001 (14,000 trees ha -1 ), another clearcut in 1996 (44,000 trees ha -1 ) and an unmanaged forest (1,000 trees ha -1 ). Photosynthetic photon flux density (PPFD) incident on sun leaves, air temperature, soil moisture, and soil temperature within the forests affected water status and carbohydrate storage in all trees. As trees became older, PPFD also influenced pigment composition and Rubisco activity in sun leaves. On the other hand, shade leaves from the oldest trees were the most sensitive to PPFD, air temperature, and soil moisture and temperature inside the forest. Contrariwise, microclimatic parameters slightly affected the physiology of shade leaves of the beech in the stand with the highest light attenuation. Air and soil temperatures were the parameters that most affected the photosynthetic pigments and carbohydrate storage in shade leaves of the youngest trees.

Foliage and fine roots in terms of growth efficiency - a comparison between European beech and Norway spruce at early growth stages

“…These findings indicated that morphological features of foliage depended on the tree size (and/or on the bio-sociological position in the stand) that in general would relate to light conditions. Our knowledge is in accordance with results of Closa et al (2012), who studied a young beech stand whose shaded foliage had much higher values of SLA (between ca 250 to 470 cm 2 per gram of mass) than the foliage exposed to sunlight (150-180 cm 2 ·g -1 ). For instance Milla et al (2008) stated that large leaves tend to require higher biomass investment per unit leaf area than the small ones.…”

“…foliage area expressed per weight unit) according to light intensity (e.g. Barna 2004;Closa et al 2012). In scientific literature SLA is the most frequent indicator of foliage structure (Reich et al 1998).…”

Microclimate in forests with varying leaf area index and soil moisture: potential implications for seedling establishment in a changing climate

“…The poor functional and quantitative understanding of forest microclimate contrasts with its high ecological relevance for many forest ecosystem processes (Breshears et al 1997;Chen et al 1999;Scharenbroch & Bockheim 2007;Vanwalleghem & Meentemeyer 2009;Closa, Irigoyen & Goicoechea 2010). For survival and growth of young tree seedlings, for instance, favourable T, air humidity and soil moisture are crucial determinants, especially until the root system is sufficiently developed and other factors such as light conditions and nutrient availability become limiting (Aussenac 2000;Wicklein et al 2012;Lloret, Penuelas & Estiarte 2005).…”

Reduced stem growth, but no reserve depletion or hydraulic impairment in beech suffering from long-term decline

“…All the leaf functional variables (LMA, mean leaf surface, percentage of N, d 13 C of total organic matter, and stomatal densities) studied were within the range reported for healthy beech trees in the literature (Aussenac and Ducrey 1977;Balsberg Påhlsson 1989;Keitel et al 2006;Wang et al 2008Wang et al , 2011Closa et al 2010;Bresson et al 2011). All these parameters were similar for healthy and declining trees.…”