Influence Of Leaf Litter Research Articles

Influence of Leaf Litter and Humus Composition on the Development of Black Spruce Seedlings: A Greenhouse Experimentation

In boreal forests in Canada, broadleaf stands are characterized by generally well-drained soils and a humus-rich layer. In contrast, spruce-moss stands are often characterized by more poorly drained soils and acidic humus layer. However, presence of these two forest types in various degrees of mixture in stands can be beneficial to spruce seedlings productivity. It was hypothesized that leaf litter and humus from pure spruces-moss stands, pure broadleaf stands, and mixed stand may influence Black spruce (Picea mariana (Mill.) BSP) seedling growth and development differently. A greenhouse experiment was carried out to evaluate the effect of different leaf litter and different humus on spruces seedlings. Our results suggest better development for seedlings grown in humus from mixed stands and pure broadleaf stands compared to humus from pure B. spruce or standard forest nursery substrate. Furthermore, leaf litter from broadleaf trees species, such as species Speckle alder (Alnus rugosa (Du Roi) R.T. Clausen), T. aspen (Populus tremuloides Michx), Willows (Salix spp.) and Paper birch (Betula papyrifera Marsh.), has shown distinct results in the growth and development of B. spruce seedlings in greenhouse. Furthermore, promotion of mixed stand can increase B. spruce productivity by improving the physicochemical composition of the forest floor.

The influence of leaf litter on the distribution of aquatic oligochaetes in the Tunca River (Edirne, Turkey)

The influence of leaf litter on the distribution of aquatic oligochaetes in the Tunca River (Edirne, Turkey)

The influence of leaf litter on the distribution of aquatic Chironomidae pupal (Diptera) fauna in Tunca River (Edirne/Turkey)

This study was designed to compare the potential differences in the colonization of Chironomidae pupal fauna in various leaf packs. The study was carried out in Tunca River (Edirne). Three stations were selected in the river and 5 different leaf packs ( Platanus orientalis L ., Ulmus leavis Pall ., Morus alba L ., Juglans regia L., and artificial Buxus sp.) were used to take samples. 20 kg potato bags were used during leaves packaging, prepared 5 packages of each leaves and a total of 25 packets were placed in each of the stations. Chironomidae pupal samples were collected from June 2012 to October 2012. The collected samples were placed in 70% ethyl alcohol, brought to the laboratory and diagnosed under stereo microscope . Then ANOVA test was used to analyse Chironomidae pupae in dates, stations, and leaf packs and 0.05 α statistical significance was used in all tests. When there was a meaningful difference, the reason was revealed by the Tukey test. Chironomidae pupae were found at most 3, 1 and 2. stations respectively and in leaf species of artificial Buxus sp. and Ulmus leavis . Eight species were identified in leaf packs. The Polypedilum ( Polypedilum ) nubeculosum (Meigen, 1804) was found to be the most common species.

The influence of leaf litter on zooplankton in floodplain wetlands: changes resulting from river regulation

1. The loss of input of leaf litter through clearing of riparian vegetation may result in significant changes to aquatic ecosystems. River red gums (Eucalyptus camaldulensis) surrounding floodplain wetlands in the Murray–Darling Basin, Australia, contribute large quantities of leaf litter, but the quality of this resource may change depending on the timing of inundation. 2. We used experimental mesocosms to test the hypotheses that zooplankton would have a greater abundance with an input of leaf litter and that fewer zooplankton would emerge from egg banks in cleared than forested wetlands. The experiment was carried out in summer/autumn and in spring to test a third hypothesis that zooplankton would respond to changes in the timing of wetland inundation as a result of river regulation. 3. In summer/autumn, leaf litter reduced zooplankton abundance by 89% at the beginning of the experiment through its influence on water quality. Only a few taxa (Polyarthra spp., Colurella spp. and the cladoceran Family Moinidae) responded positively to leaf litter when water quality improved later in the experiment, indicating a switch in the role of leaf litter from a non-trophic to a trophic pathway. 4. In spring, microcrustaceans emerged in smaller numbers from sediment sourced from cleared compared to forested wetlands, reflecting different communities in these two wetland types and/or disturbances to the sediment that interfere with emergence. 5. Although leaf litter appears not to be an important resource for zooplankton in floodplain wetlands, riparian clearing may have lasting effects on future emerging zooplankton communities. Additionally, river regulation may have considerable impacts on the influence of leaf litter on zooplankton, which has implications for the management of floodplain river systems.

Influence of leaf litter on corrosion of gutters

Leaf litter is commonly deposited onto roofs, where it affects the local environmental conditions that control the degradation of roof sheeting and gutters. This study investigated the chemical nature and corrosivity of electrolytes resulting from the infusion of deionised water with leaf litter. Leaf litter specimens were collected from a variety of tree species commonly found in southern Australian suburbs, and from gutters in which the leaf litter had accumulated. After infusion for approximately three weeks, leaf litter suspensions were filtered and the electrolytes present in the filtrates were analysed to determine their chemical composition and pH levels. The filtrates from leaf litter obtained directly from trees tended to contain higher concentrations of salts and increased acidity compared to the suspensions from leaf litter sampled from gutters. The corrosivity of the electrolytes was explored electrochemically by potentiodynamic analysis of rolled zinc coupons immersed into the filtrates. Leaf litter was found to influence corrosion rates by increasing the acidity of solutions, and through the release of chloride ions during organic matter decomposition. Soluble products of leaf litter decomposition (i.e. fulvic acids) appeared to provide limited protection against corrosion. Over time, the aggressiveness of electrolytes in gutters should decrease as rain events leach salts from leaf litter, and pH should be buffered through the adsorption of carbon dioxide and possibly through the deposition of airborne dust such as mineralogical particles. In addition to the chemical impacts of leaf litter on corrosion, it can also result in gutters being exposed to longer periods of wetness. Data from wetness sensors installed in both clean and dirty gutters showed that, once wet, gutters containing leaf litter can take over twenty-five times longer to dry than clean gutters. Although there are many variables involved, it has been shown that leaf litter can influence long term zinc corrosion rates by a factor of over 2.

Decomposition of willow-leaf litter in a short-rotation forest in relation to fungal colonization and palatability for earthworms

The influence of leaf litter from three Salix spp. on fungal growth and microbial decomposition was studied using 1-mm-mesh litter-bags, and the effect on additional soil macrofaunal activity was studied by measuring litter disappearance from 4-mm-mesh bags and under 4-mm-mesh nets. Mineral macro-elements, water-and ethanol-extractable substances, lignin, and protein-precipitating substances (astringency) in the litter were determined, taking contaminating of the litter with soil particles into account. As expected, the litter disappeared more quickly from the large-mesh bags than from the small-mesh bags, which was attributed to earthworm activity. During the 1st year, the rate of leaf disappearance from both types of bags and under the nets was much higher for S. daphnoides than for S. viminalis and S. fragilis. The lower initial astringency, related to the tannin content, of the S. daphnoides litter might account for this difference. Tannin metabolites probably hampered both microbial decomposition and earthworm acceptability for some time also after the astringency was lost. Neither the content of macronutrients nor that of the other organic fractions studied can be assumed to have had any effect on weight losses due to microbial decomposition. Although, the S. daphnoides leaves initially contained the least amount of fungal mycelium (m g-1 dry weight), the increase after contact with soil was most pronounced in this litter. The species composition of Fungi Imperfecti in the leaves of S. viminalis and S. daphnoides differed only for fresh litter, whereas the number of isolates was somewhat higher for S. daphnoides throughout the study. Similar seasonal variations in fungal composition occurred in both the S. viminalis and the S. daphnoides litter.

Influence of Leaf Litter and Soil Moisture Regime on Early Establishment of Pinus pungens

-The influence of leaf litter and soil moisture regime on early establishment of table mountain pine Pinus pungens Lambert was evaluated in a greenhouse study. The influence of leaf litter on emergence and survival of seedlings was substantial and varied with litter type. Pine litter generally supported greater seedling emergence than litter-free or oak-litter treatments, and only under daily watering did emergence in the litter-free treatment approach that observed in pine litter. Oak litter, in all but the lowest soil moisture regime, depressed seedling emergence relative to that recorded from pine litter and litterfree treatments. Significant statistical interactions indicated that the effects of leaf litter and soil moisture regime were not independent; leaf litter significantly decreased evaporative losses which resulted in greater seedling emergence and survival at low soil moisture regimes.