Development Of Herbaceous Vegetation Research Articles

Herbaceous vegetation under planted woody species on coal mine spoil acts as a source of organic matter

The present study was conducted to examine the status of herbaceous biomass development under rehabilitated coal mine spoil by establishing indigenous woody species in India's northern dry tropical region. Since mining activities for coal and minerals are prime industrial activities in this region; therefore, through these activities, a significant size of dry tropical forest ecosystems is destroying at unprecedented rates. Thus, the primary objective of the present study was to understand the influence of planted woody species on herbaceous biomass development. Estimation of herbaceous biomass was accomplished once in 1995 and 2007 under plantation stand of four native woody species. Among planted woody species, maximum herbaceous biomass was quantified at the 5th-year stand of Tectona grandis and lowest at the 17th-year stand of Dendrocalamus strictus. Family Poaceae contributed the maximum in herbaceous biomass production across all plantation stands. A declining trend was observed in herbaceous biomass production as the age of plantation stand increases, reflecting the impact of stand characteristics such as woody species basal cover and canopy cover on herbaceous vegetation development. Herbaceous biomass was positively correlated with species diversity at both ages of plantation stands, emphasising the facilitative role of species for organic matter build-up in disturbed habitats. However, increased competition between herbaceous species for space, nutrients and decreased penetration of light through the closed canopy of planted woody trees significantly influences herbaceous diversity under plantation stand.

Inorganic Fertilization at High N Rate Increased Olive Yield of a Rainfed Orchard but Reduced Soil Organic Matter in Comparison to Three Organic Amendments

Strategies for waste valorisation from domestic and agro-industrial activities must be pursued, and its use as a soil amendment is an interesting possibility. In this four-year study, the effect of applying municipal solid waste (MSW), farmyard manure (FYM), bottom wood ash supplemented with nitrogen (Ash + N), the inorganic fertilization common in the region (50 kg ha−1 N, P2O5 and K2O) (Control) and this inorganic fertilization supplemented with 70 kg N ha−1 (High N) was assessed in a rainfed olive grove planted in a shallow soil with low organic matter and managed with conventional tillage. The High N treatment significantly increased olive yield in comparison to the other treatments (165% more than MSW), and soil available N proved to be the main driver for tree productivity. MSW and FYM increased soil organic matter, as well as the levels of phosphorus and cation exchange capacity, leaving good indications for future production cycles, although during the four years of the study these treatments provided little N to the trees. The High N treatment significantly reduced soil organic matter (63% less than MSW). The result was attributed in part to the soil management system that did not allow the development of herbaceous vegetation, but also to an effect known as “added N interaction”, in which the excess of inorganic N in the soil might have contributed to accelerate the mineralization of native soil organic matter, an aspect that compromises the sustainability of this fertilization strategy. Although MSW and wood ash are sometimes associated with risks of environmental contamination with heavy metals, in this study the levels of heavy metals in soils and in plant tissues were not of concern.

Influence of climatic factors on the energy potential of broadleaf phytocoenosis forest bedding

The study of the energy potential of forest bedding in the deciduous forest areas of the “Lisnyky” Nature Reserve of the Holosiivsky National Nature Park revealed the nonlinear nature of its annual dynamics. The main sources of replenishment of the organic stock of this component of broadleaf forest phytocoenosis were the active development of herbaceous vegetation in spring and significant leaf rainfall in autumn. At the same time, significant changes in the processes of accumulation and decomposition of organic matter of forest bedding occurred under the influence of climatic factors such as temperature and precipitation. The experimental site was located in moderately moist oak forest ass. Convallario majali-Quercetum roboris Shevchyk & V. Sl. in Shevchyk & al. 96. The age of the old Quercus robur oak trees, which occupy the first tier of the forest, exceeds 100 years. The second tier is formed by other broadleaf species, Acer platanoides, A. campestre, A. tataricum, Carpinus betulus, Fraxinus excelsior and Tilia cordata, up to 30 years old. The energy reserve was calculated from the dry organic matter content. The obtained data were compared with meteorological data of the corresponding month of the year and correlation coefficients were calculated. Correlation analysis confirmed the relationship between climatic factors and the energy potential of forest bedding. The inverse of the mean force (R = -0.515) shows the relationship between the energy potential of the forest bedding and the average monthly temperature and the high direct correlation between the energy potential and the amount of average monthly precipitation (R = 0.755). In general, forest bedding can be considered an important component of the ecosystem, which responds quickly to external factors and characterizes the state of the forest ecosystem, and its energy potential can be an effective indicator of forest ecosystem stability in climate change monitoring.

A controlled-release fertilizer improved soil fertility but not olive tree performance

The use of a controlled-release fertilizer (CRF) was studied in a traditional rainfed olive grove in a Mediterranean climate where precipitation is very irregular, particularly in the spring. The objective of the study was to assess whether a CRF can improve the olive tree's performance compared to a conventional nitrogen (N) fertilizer (CF), by supplying N gradually and reducing the risk of potential N loss from leaching. The fertilized treatments showed better plant N nutritional status, which resulted in enhanced net photosynthesis and higher leaf concentrations of total soluble sugars, chlorophylls and soluble proteins which, in turn, increased olive yield by 43% in comparison to the unfertilized control. However, in general, no significant differences were found between fertilized treatments in the performance parameters of the trees evaluated, including olive yield. Somewhat unexpectedly, CRF consistently increased the soil organic carbon (C) (29%), kjeldahl-N (75%) and easily extractable glomalin-related soil proteins (EE-GRSP) (60%) and total GRSP (T-GRSP) (122%) compared to the CF. The result was ascribed to a stimulus on the development of herbaceous vegetation and eventually on the activity of the roots of the trees due to the higher soil inorganic-N availability in the autumn. Thus, some soil inorganic-N in the autumn seems to comprise a low risk of leaching, since weeds act as a catch crop and convert this inorganic N into an organic substrate, with potential benefits in the long-term for the agro-system.

Effect of gap size on tree species diversity of natural regeneration - case study from Masaryk Training Forest Enterprise Křtiny

Forest gaps remain the optimal forest management practice in modern forestry. Upon all the physical properties of forest gaps, the ‘gap size’ feature stands out as an essential property. The effect of gap size on tree species composition and diversity of natural regeneration in forest gaps of different sizes was investigated. Eight research forest gaps were selected from the Training Forest School Enterprise, also called Masaryk Forest in Křtiny, a temperate mixed forest in the Czech Republic. By given gap sizes, small (< 700 m<sup>2</sup>) and large gaps (≥ 700 m<sup>2</sup>) were defined. Forty-one (41) regeneration microsites (RSs) of 1 m<sup>2</sup> circular area at 2 m intervals were demarcated within each forest gap. These RSs served as data collection points. From the total of eleven (11) species enumerated, large gaps obtained higher species composition (10) and diversity (Simpson = 0.5 1-D; Shannon = 1.0 H and Pielou’s evenness = 0.5 J indices) records, yet, small gaps presented favourable conditions for prolific natural regeneration significantly. Light-adapted species demonstrated no significant difference (P > 0.05) between small and large gaps, however, intermediate and shade-tolerant species were significantly higher (P < 0.05) in small gaps. There were progressive declines in height growth of natural regeneration from 0–20 cm to 21–50 cm and 51+ cm in small and large gaps at R<sup>2 </sup>= 99% and 88%, respectively. <br /> The development of herbaceous vegetation in small and large gaps had positive and negative effects on the natural regeneration of Fagus sylvatica and Abies alba species, respectively.

The effect of planted tree species on the development of herbaceous vegetation in a reclaimed opencast

The establishment of plantations is the most common method of opencast reclamation, but few studies have addressed the influence of planted trees on the recovery of biodiversity in new forest sites. The goal of this study was to determine whether the formation of herbaceous vegetation was dependent on the tree species planted on the spoil of a reclaimed oil shale opencast in northeastern Estonia. From 2002 to 2005, the vegetation in eight different site types (distinguished according to the age and composition of tree layer) was surveyed. The results confirmed that the development of herbaceous vegetation was controlled by the dominant species of tree layer. The highest number of herbaceous species was recorded in naturally developed mixed stands. As compared with other site types, the herb layers of the pioneer stage (the vegetation in recently reclaimed sites) and alder stands were the most different. In the terms of the competitive, stress-tolerant, and ruderal strategy types, alder (Alnus spp.) stands tended to enhance the growth of competitors, whereas stress-tolerant species were more abundant in pine stands. Herbaceous vegetation remained sparse in coniferous stands, whereas broad-leaved trees tended to improve the performance of herbaceous species. Our results concur with the suggestions that planting with different tree species is one prerequisite for the development of diverse herb layer.

Changements climatiques et paléocéanographiques en Afrique centrale atlantique au cours de la dernière déglaciation : contribution palynologique

Palynological analyses of two marine cores recovered from the Congo fan provide a high-resolution record of palaeoclimatic changes that have taken place on the adjacent continent and the margin since the Late Pleistocene. Between 27 and 14 14C kyr BP, the basin was characterized by well-developed grasslands, and the coastal area was under the influence of seasonal coastal upwellings. From 14-13 14C kyr BP, significant changes in the rainforest and coastal vegetation are recorded, characterized by an increase of the rainforest until 5-4 14C kyr BP, followed by the development of herbaceous vegetation. Sea level fluctuations are documented by Rhizophora frequencies.

Phenology, diet, and water turnover rates of Negev desert chukars

As a field test of a hypothesis on the relation of total water intake and diet in free-ranging Negev chukars ( Alectoris chukar sinaica ), we measured meteorological and phenological conditions and the birds’ water turnover rates and food habits during the winter of 1981–2. A late winter rise in water turnover rate corresponded to the abundance of herbaceous seedlings on sample plots and to increased intake of green forage. Water turnover rates were significantly lower than in a previous winter of greater rainfall and of more advanced and extensive development of herbaceous vegetation. Estimates of the birds's total body water (TBW) volumes indicated that they were in better body condition during the present study than in the winter of 1980–1, probably owing to diet-related differences. Results suggest that the birds’ food was largely a function of forage availability, and that their diet and body condition are closely linked to meteorological and phenological events which exhibit strong temporal variations in the Negev desert.