Ash for the future: defining European ash populations for conservation and regeneration
The research programme FRAXIGEN will strengthen the scientific basis for the sustainable conservation and regeneration of ash genetic resources in Europe through improved understanding of three native Fraxinus species. Genetic structure and gene flow among natural European populations, and the influence of the reproductive system will be studied in detail. This combined with trials to investigate the distances over which environmental adaptation occurs, will provide a rational basis for defining ‘local’ population (as required by EU directives) as well as insights into (a) the resilience of populations to global change, and (b) how anthropogenic selection has affected adaptive variation. Partners from northern and southern Europe will collaborate closely to deliver scientifically – based guidelines for defining provenances and selecting sustainable seed sources. Dissemination methods will include website and regular meetings with end users.
Allometric relations in legume – grass mixture under drought
The study of allometric relations could interpret the competitive capability of different species that grow in mixture. The grow up way of canopy was measured in 1:1 mixture of Medicago sativa with Festuca arundinacea. The experiment was contacted in Drama, in northern Greece, in semiarid climate and infertile soil without any fertilizer apply, during the period from May to July in the years 1996 and 1997. Two levels of water regimes were used: A. only rainfed B. supplementary irrigation. Leaf area, dry weight of the leaves and shoots dry were measured in pure and mixed culture for each species. Leaf Area Ratio (LAR), Leaf Weight Ratio (LWR) and Specific Leaf Weight (SLW) were calculated. Results shown that, during summer season, the LAR was decreased in plants grown in rainfed conditions, compared to plants grown under irrigation. The cultivation in mixture influenced the LAR only under irrigation but in different way for each species. The LAR was increased in Festuca arundinacea and was decreased in Medicago sativa.
Effect of nutrient availability on competition among pasture species
The effect of N, P and K availability on the growth and competition among pasture plant species was examined in two experiments. In the first experiment, plant communities consisted of six pasture species were developed in wooden boxes for three years using three nutrient treatments, i.e. addition of K and P (treatment –N), N and K (-P) and N and P (-K). Eighteen replicates were used. In the second experiment, five pasture species, in monocultures and mixtures, were grown in pots with sand using a complete randomized design with four replicates. Plants treated with nutrient solution consisted of the combination of two P levels (1 and 20 ppm) and three K levels (4, 16 and 64 ppm). In the first experiment, the changes of species Biomass Duration were negatively correlated with species’ P tissue concentration when P was limited. In the second experiment, dicot species had higher P concentrations in their shoots than the grasses when P was limited. The reverse was found for the grasses. The increase of K availability tended to favour the grasses in the mixtures, while the increase in P availability tended to favour the dicot species. The results indicated that species with minimal tissue concentrations for a nutrient were the most competitive when this nutrient was limited.
Evaluation of small ruminant production systems In the area of Lagadas County
The production systems of small ruminants (sheep and goats) were investigated in eight Municipal Districts and Settlements throughout a representative area of Lagadas County in winter 2002. Shepherds of the area were interviewed and questionnaires were used to investigate the characteristics of the production systems. The Municipal Districts, according to their elevation, were grouped into three zones: the low zone (<200 m), the middle (200-600 m) and the high zone (600-1000 m). The number of goats (14.950) that are raised in the area is larger than that of sheep (11.248) and is increasing gradually from the low zone (3.482) towards the higher one (7.401). Most animals remain at the Municipal Districts all year round, whereas only a low percentage is moved out (transhumance). Throughout the study area the production systems are based on rangeland utilization, complemented by temporary leys during winter and cereal stubble during summer period, but extensive use of feedstuffs is made as well (hay and concentrates), thus making them semi-intensive. Sheep and goats graze at the low zone for 9-10 months, at the middle one for 7-9 months, whereas at the high zone from 6-7 months. The feedstuffs which are given to the animals are corn, wheat, barley, rye, oat, alfalfa hay, cotton seed cake and beet pulp.
Use of machinery of the improvement of pastures
The use of machinery for improving pastures was considered necessary in the recent years. The reasons that imposed their usage on one hand was the increase of the work volume in the pastures (cultivating, improving and harvesting works) and on the other the need of reducing the exploitation time as well as the total cost of each work. The rapid development of modern machinery provides us with the possibility to select the right machine aiming at the quick and suitable exploitation on one hand and the reduction of the cost of each work in the pastures on the other. One of the modern machines that can be used for the improvement of pastures (removal of shrubs) is the head with a rotating chain (cutting or crushing mechanism). The machine is adjusted easily on the tractor motorized by it. In this paperwork was studied the performance of the above machine and was calculated the hourly operation cost in order to draw out conclusions (production cost), able to help out the forest praxis as much as for the quality as well as for the reduction of he cost of the above works.
