DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 13/2005 str. 132 <-- 132 --> PDF |
S. Pcrić. V. Topic. Ž. Orcšković. R. Maradin: BIOLOGICAL CONTROL OF EXCAVATIONS AND DUMPS Šumarski -SUPLEMENT (2005), 120-132 the forests of pubescent oak and white hornbeam (Querco- Carpinetum orientalis H-ić 1939), as a final and climate-conditional stage in the development of the vegetation in this area. In the past, however, these areas were devastated by long-term uncontrolled anthropogenetic impacts (man and cattle) and climatic factors. What survived were only the prickly brushwood and bushes, or herbaceous plants with developed subsoil parts. Thus, in this area at the bottom of Velebit common species are juniper (Juniperus oxycedrus), Christ´s thorn (Paliurus spina christi), blackthorn (Crategus transalpine), blackberry (Rubus ulmifolius), and wild asparagus (Asparagus acutifolius). The intensive cattle grazing tradition was abandoned quite some time ago, and so was logging, which has resulted in progressive forest vegetation succession. Many species have returned into this area, e.g. black ash (Fraximus ornus), white hornbeam (Carpinus orientalis), Montpelier maple (Acer monspessulanum), perfumed cherry (Prunus mahaleb), terebinth (Pistacia terebinthus), and stone lime-tree (Phillvrea latifolia); the come-back of pubescent oak (Pubescent oak) has also been noticed. Slowly rising above the juniper and Christ´s thorn, they will contribute to the beauty of the area. The following are the commonest undergrowth species: Helichrysum italicum, Salvia officinalis, Chrysopogon gryllus, Festuca illyrica, Sesleria autumnalis, Bromus erectus, Koeleria splendes, Eryngium sp., and Euphorbia sp. BIOLOGICAL AMELIORATION Basic principles The biological amelioration of the dumpsites is mainly carried out for the protection of the landscape. The task of the ameliorating operation is to create the substrate that will continuously supply the vegetation with water, air and nutrients. Before any ameliorative work begins, the area where seedlings will be planted should be spatially planned, and the surface soil loosened. The area will then be topsoiled, which is the basic ameliorating factor that will create favourable biological, physical and chemical conditions for the growth of the new plants. Soil preparation creates optimal conditions for growth and development, i.e. the favourable water- air relations that enable the functioning of the optimal life- sustaining biochemical processes. The manner and intensity of soil preparation will depend on the soil state, planting method, use of mechanisation, etc. Good soil preparation is often a deciding factor for the success of planting. Seedlings and planting methods Planting distance can be regular or irregular. The former is applied whenever the terrain allows (stumps, rocky ground, etc.), and can form rectangles, squares, triangles, or hexagons, with exactly determined spaces between the plants and the rows. Irregular planting distance is particularly applied in karst areas, as planting can be done only where there is enough soil to dig a hole of satisfactory dimensions. Planting can take place with bare roots or balls. Damaged or too long roots are cut off. Where needed, crown is also trimmed to balance the water/nutrient supply between it and the roots. With coniferous tree seedlings, damaged roots are very carefully trimmed, and sometimes also the lowest branches. The space around the root must be well filled with soil, and the seedling firmly planted. Attention should be paid to the planting depth, which should be - after the soil has settled down-same as in the nursery before the seedling was taken out. This means that the planting should be neither too deep, nor too shallow. In the afforestation of the terrain with stumps, rocks etc., the seedlings should be planted near such objects for their protection in the first years of their lives, and because of better soil conditions. After taken out from nurseries, seedlings are susceptible to drying, and therefore should be planted into peat, or protected otherwise from sun and wind. In afforestation, the ecological requirements and biological properties of the individual tree species should be respected in relation to the habitat conditions. Seedlings can be planted into holes, crevices, embankments, mounds, and trenches. The following are the advantages of planting the seedlings with coated roots: roots are not damaged when taken our; protection during transport and planting; great proportion of rooting; continued growth after planting without stress; possibility of planting throughout the year - a significant factor. In addition, greenhouse seedling production enables corresponding watering and protection of plants, which shortens the production process. Accordingly, the dumpsite amelioration should be carried out by planting the seedlings with coated roots. |