Ecological approach of cyanogenesis cost in Trifolium repens
The acyanogenetic form ( ac / li ) of Trifolium repens is more grazed than the cyanogenetic form (Ac / li) although the acyanogenetic form is more frequent in the Trifolium ‘s populations. This fact could be explained by the cyanogenetic cost which seems to affect all the parameters of growth especially the ability of the reproduction of Trifolium repens. Measurements of flowers ‘ number per plant took place from April till August, in plants which were planted in pots of 3L volume , in pure stand and in mixed ( under low density were 1 00, 150, 200 plant / m2 and under high density 200, 400, 600 plant / m2 ). The results of these experiments were the following :
( a ) The number of flowers per plant decreased vs the density faster in the cyanogenetic form than the acyanogenetic one.
( b ) The number of flowers per plant after the first cutting seems to be increased especially in the acyanogenetic fonn and
( c ) The mixture of the two forms seems to favor the production of flowers in the acyanogenetic form.
Range management and forestry
The rangelands of Greece constitute the ιnain national asset of the primary production of the triptych “forestrylivestock- agriculture. They coιnprise all those areas which are not suitable for intensive forest or agricultural developιnent and are ιnainly covered by phryganic, herbaceous and shrubby vegetation or mixed with sparse forest trees. The obsolete forest law and the coιnplex land tenure, mainly based on use rights and titles froιn the Ottoman occupation suspend the development of forestry and range management. The lack of national land survey or national land use planning as well as the improper exploitation of productive land are the main factors of the unclear limits between forests, arable lands and pastures and they are responsible for the bad management of forest ecosysteιns and rangelands. Today, the management of the mountainous forest areas must be changed and crried out according to the multiple use principle and the needs of the modem man. The use of forest resources must be done according to the forest supply of goods and services, without overlooking the utilisation of rangelands for livestock products. The forests and pastures must be balanced and the extension forester should undertake the difficult work of management of forest areas, with the simultaneous development of forestry and range management.
Agroforestry: The combination of forestry, agrigulture, and pastoralism
Agroforestry is discussed in this article as an Integrated Land Use System. The major biological, economical, and sociological advantages and disadvantages of agroforestry as compared to intensive agriculture are discussed. The criteria and major classification systems are mentioned. The example of the chestnut forest of Agios Nikolaos, Eurytania, is given as agroforestry practice in Greece. The products from the forest represent a considerable income for the villagers involved in its cultivation. Finally, discussion and recommendations about Agroforestry in Greece are ιnade.
Research for the development system of inventory, classification, appreciation and mapping of rangelands in the Mt. Menikio of Drama for the determination of productivity
The grazing forest areas (rangelands) in the mountainous area of Menikio in the Prefecture of Drama have been inventoried with the use of Geographic Inforrnation Systems (G.I.S .) and orthophotomaps. The possibilities of G.I.S. have been exploited (digitazation of maps, creation and development of topology, data base update, multitemporal update of maps, etc) and new thematic maps have been created based on the inforrnation that exists in the ( digital) data base. The results of the inventory of the rangelands are presented on color maps at a scale 1 :20.000, where the different types, series, and subtypes are appeared. The G.I.S. can be a useful tool for the inventory ofrangelands.
ν aluation of forest ecosystems, forage production in Greece
The planning of forest ecosysteιns under the axiom of sustainable yield needs the combination of forest uses for optimization of forest land production. Το approach this successfully, the planner should have available information about the production relationships between the forest goods and, also, coιnparable units for all goods. An attenψt was ιnade, in this paper for the valuation of forest forage in monetary tenns in order this use to be incorporated properly in the decicion ιnaking process for the forest ecosystems. Using common valuation methods i.e. production analysis, opportunity cost and shadow prices, the forage of the country’s forest ecosystems can acquire a value of about 200 billion drachιnas/year (about 1.45% of the GNP), when the value of wood production is 30 billion drachmas/year (0,22% of the GNP).
