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://www.ipni.org [accessed 5 March 2012] Jennings, S. B., Brown N. D. and Sheil, D. 1999. Assessing forest canopies and understory illumination: Canopy closure, canopy cover and other measures. Forestry 72: 59
Elek, Z., T. Magura and B. Tóthmérész. 2005. Effect of canopy closure of a young Norway spruce plantation on ground beetles. In: G.L. Lövei and S. Toft (eds), European Carabidology 2003. Proceedings of the 11th European Carabidologists' Meeting . DIAS
Bivalve larvae use catch muscles for rapid shell closure and maintenance of the closed condition. We used specific antibodies against the muscle proteins together with phalloidin and neuronal markers, FMRFamide and serotonin (5-HT), to analyze mutual distribution of muscle and neuronal elements in larvae of the mussel, Mytilus trossulus, and the oyster, Crassostrea gigas. At trochophore and early veliger stages no anatomical connections between muscular and nervous system were detected. By the pediveliger stage the 5-HT innervation of the anterior adductor developed in oyster only, while rich FMRFa innervation of the adductor muscles developed in both species. Possible roles and mechanisms of FMRFamide and serotonin in the regulation of the catch state are discussed.
Different types of forest use significantly changed the structure and species composition of European temperate forests. Herbaceous species and seedlings are important parts of the forest ecosystem, thus it is necessary to understand the effects of stand characteristics on the species composition of the understory. In our study we assessed the main factors that affect the species composition of herb and tree seedling assemblages in Quercus petraea and Q. cerris dominated stands (age 50–150 years) in the Bükk Mountains, Hungary. The relationship between the studied assemblages and explanatory variables (tree species composition, stand structure, canopy closure and topography) were explored by Redundancy Analysis (RDA). The occurrence of herbaceous species was affected by canopy closure, stand structure (mean DBH and DBHcv of trees), topography and the density and diversity of shrub layers. Oak forest species were associated with more open stands with sparsely distributed large trees, while mesic forest species were positively associated with heterogeneous stand structure, low shrub density, and western exposure. Seedlings of trees and shrubs showed a dispersal limited phenomenon. The composition of seedlings was significantly influenced by the mean DBH of trees, the structural heterogeneity of the overstory, the tree species diversity and the density of shrub layers. However the seedlings of both dominant oak species required the same stand structure, sessile oak was able to regenerate almost exclusively in those stands where it was dominant in the overstory, which is significant for the management of the species. Generally, forest management affects species composition and structure of the overstory, accordingly it had direct and indirect effects on the understory community as well.
The subject of the present study is the monitoring of the hardwood groves at the Martonvásár Manor Park with the involvement of 20 earlier (recorded in 1980–1981) and 20 current (recorded in 2011–2012) phytocoenological relevés. The manor park was created in the first half of the 19th century. Since then the woods along the St László stream have developed into species-rich and semi-natural forests, which can be identified as related to the oak-ash-elm groves (Scillo vindobonensis-Ulmetum) of the Zámoly Basin and the Csepel Island. The results of the current monitoring repeated 30 years after the first survey show momentous changes in forest dynamics such as the ageing-related opening of the upper canopy and an intense closure of the lower canopy and shrub layer. The ratio of the invasive species doubled. Present findings may provide additional information for long-term forest ecology research, however, results could be considered as changes of a semi-natural hardwood forest with minimal human impact.
The tree canopy characteristics of two broadleaved woods in southern England were quantified in terms of two independent measures of structure, canopy height (calculated using heights ≥ 1 m) and percentage canopy cover (derived using heights < 1 m), using airborne Light Detection and Ranging. The woods differed strikingly in structure due to their management systems; one was predominantly mature oak and the other coppice, comprising a patchwork of growth stages. Fine-scale relationships between breeding bird species distributions, determined by mapping censuses, and canopy height and canopy cover were assessed. Despite the differences in structure, species showed great consistency between the woods in their rank positions across gradients of canopy height (rank correlation between woods, r = 0.77, p < 0.001) and canopy cover (r = 0.61, p = 0.003). In both woods, and especially the mature oak (R 2 > 0.90, p < 0.001), there was a positive correlation across bird species between the mean values of canopy height and canopy cover associated with the mapped locations of each species. We suggest that canopy height acts as an effective surrogate of woodland structure and can be applied as a predictor of woodland bird composition and distribution, at least in lowland British conditions. Species associated with young growth were more restricted by habitat structure, as measured by differences in canopy height and canopy cover between the two woods, than were species associated with taller canopies. Remote sensing of canopy height potentially offers a simple, effective way of assessing habitat availability for many species, at both woodland and landscape scales. This may be especially relevant for species dependent on highly transient vegetation structures associated with the early pre-canopy closure stages of forest growth.
In this study sap flow dynamics of mature sessile oak trees (Quercus petraea) in a marginal sessile oakturkey oak forest was investigated in 2009. That year spring was dry without significant rain in April and May and the driest month was August. Due to the extreme weather conditions the volumetric soil water content (SWC) of upper 30 cm was low on experimental days in May (0.13–0.14 cm3 cm−3) but it reached the lowest value in August (0.08 cm3 cm−3). Sap flow was measured in a dominant and a co-dominant tree by heat dissipation method from 26 March till 30 October. In the present paper several three-day long periods of the continuous seasonal recordings were chosen to represent the effects of typical weather conditions and different stages of canopy development on sap flow dynamics. The daily maximum sap flow density values of dominant and co-dominant trees were similar (0.30–0.32 cm3 cm−2 min−1) in moist period (July). Rains and transient increase of SWC after proceeding drought resulted in change of diurnal course of sap flow in experimental days of July. In this period dominant trees also showed considerable sap flow (0.19 cm3 cm−2 min−1) during night hours and short sap flow peaks in early morning (6:00 to 8:00 a.m.) indicating the refilling of desiccated tissues. After the progressive drought in August the daily maximum sap flow density decreased to 0.07 cm3 cm-2 min-1 in dominant tree and to 0.12 cm3 cm−2 min−1 in the co-dominant. Both trees exhibited gradual stomatal closure from morning hours.
This study aimed at the effects of habitat age on the reproductive rate of three ground beetle species that are common and widely distributed in forest ecosystems of Europe ( Abax parallelepipedus (Pill. & Mitt.), Pterostichus oblongopunctatus (F.), Pterostichus burmeisteri (Heer.)). The study sites comprised comparable age classes, i.e., young stands, mature stands, and mature forests with upcoming and established natural regeneration of four different forest types, namely pure stands of spruce and Douglas fir, and mixed stands of spruce-beech and oak-beech. As an indicator for the reproductive rate of female beetles, the number of ripe eggs in the ovaries and the duration of the reproduction period were investigated from captures of pitfall trapping (n = 8 per site). The dissection of a total of 1236 females uncovered 1704 eggs. A broad spectrum of environmental factors including microclimate (temperature, humidity, precipitation), soil parameters (moisture, pH, thickness and coverage of litter layer) and vegetation characteristics (coverage of moss, herb, grass, shrub and natural regeneration, degree of canopy closure) was assessed to reveal the relevant factors influencing the reproductive success.Within the forest types, the egg-load of the ground beetle species showed statistically significant relations to the age of the stand type. For A. parallelepipedus , a quite uniform reaction pattern was evident with significantly higher egg-loads in the mature forests compared to the young stands. This was accompanied by a longer duration of the reproduction period. A stronger influence of the forest type was obvious for the egg-load of Pt. oblongopunctatus and Pt. burmeisteri . The reproductive rate was generally increasing with temperature aspects in forest sites and was significantly influenced by moisture parameters. The mean maximum temperature of the habitat cared for most of the variation in A. parallelepipedus (61.4%), while the mean minimum temperature explained 60.7% of the reproductive potential in Pt. oblongopunctatus . The variation of Pt. burmeisteri was best explained by the humidity of the air (49.4%). Thus, the results of our study emphasize the role of abiotic parameters on the reproductive rate of ground beetles.
. , Hou , Z. , Zhao , F. , Liu , X. 2011 . Hydrogen sulfide mediates ABA-induced stomatal closure of Vicia faba L . Acta Bot. Boreal-Occident Sin. 31 : 298 – 304 . (in Chinese
-recapture methods to violations of the closure assumption. Ecology 80:2517–2525. Kendall W.L. Robustness of closed capture-recapture methods to violations of the closure assumption
