ABSTRACT
Objectives of this study were to investigate effect of exclosure on understory vegetation recovery and determine the time required for understory vegetation recovery in a forest recreational site. Recovery of understory vegetation in an exclosure was monitored for three growing seasons and plant density and vegetation cover were determined for each plant species. Exclosure was compared with control plot for the Shannon index of diversity. Results showed that a total of 33 (18 woody, 15 herbaceous) plant taxa were established in the exclosure while 42 (16 woody, 26 herbaceous) were encountered in the forest plot. Quercus petraea (Mattuschka) Liebl. subsp. iberica (Steven ex Bieb.) Krassiln. had the highest density both in the exclosure (30.37 plants m-2) and forest plot (25.75 plants m-2) and followed by Hedera helix L. (28.44 plants m-2 in the exclosure, 23.33 plants m-2 in the forest plot). Plant species recovered in the exclosure did not survive very long as growing season progressed, top soil dried, and canopy closure increased. H. helix L. was the major dominant plant species for vegetation cover in both exclosure (45.23 %) and forest plot (45.08 %). There was a significant difference between plots for species diversity and forest plot had diversity index of 1.01 while exclosure had a diversity index of 0.741.
ABSTRACT
The objective of this study was to compare density, vegetative cover, basal area, height growth, aboveground biomass production, frequency, floristic composition, and species diversity of understory vegetation growing in Hungarian oak (Quercus frainetto Ten.), Oriental beech (Fagus orientalis L.) and a mixed stand of both species (90% Hungarian oak and 10% Oriental beech) with the same crown closure. Understory vegetation was sampled with a quadrat of 0.5 m x 1 m along the 25 m-long transect lines in each stand. A total of seventeen perennial plant species from thirteen different families were found in the three stand types and all of them were present in Hungarian oak stand, eleven in Oriental beech stand, and seven in the mixed stand of Hungarian oak and Oriental beech trees. Results showed that stand types had a statistically significant effect on density, vegetative cover, basal area, height growth, biomass production, frequency, floristic composition, and species diversity of understory vegetation. Total understory vegetation density was the highest for Hungarian oak stand with about 136 plants m-2 and the lowest for the mixed stand of Hungarian oak and Oriental beech with 44 plants m-2. In addition, the Hungarian oak stand had the most diverse understory vegetation with about 4.3 different plant m-2, followed by the Oriental beech stand with 3.7 plants m-2, and the mixed stand of the Hungarian oak and Oriental beech with 2.7 plants m-2. Species density and diversity were the highest in Hungarian oak stand whereas aboveground biomass production and height growth of understory vegetation were highest in the mixed stand.
ABSTRACT
This study was carried out in plastic containers to compare growth performances of perennial ryegrass, orchardgrass and tall wheatgrass to be given priority in revegetation studies in Turkey. Three pre-germinated seeds of each grass species were planted separately into the soil in the black plastic containers. Seedlings were harvested 2, 4 and 6 months after planting pre-germinated seeds and measured for percentage of seedling emergence, rooting depth, height growth, leaf and tiller development and shoot and root weights. Germination percentage was 97.8% for perennial ryegrass, 64.1% for orchardgrass and 11.6% for tall wheatgrass and perennial ryegrass had the greatest whereas tall wheatgrass had the lowest seedling emergence. Two months old rooting depth was 25.66 cm for perennial ryegrass, 20.56 cm for orchardgrass and 30.10 cm for tall wheatgrass. At the end of the study, perennial ryegrass developed about 104 tillers per plant while they were 21.4 and 36.6 tillers per plant for orchardgrass and tall wheatgrass, respectively. Orchardgrass produced greater shoot and root biomasses than tall wheatgrass and similar to perennial ryegrass. All these meant that perennial ryegrass had a better growth performance than orchardgrass and tall wheatgrass to be used for erosion control.