DIGITALNA ARHIVA ŠUMARSKOG LISTA
prilagođeno pretraživanje po punom tekstu
ŠUMARSKI LIST 11-12/1968 str. 38 <-- 38 --> PDF |
A STUDY OF THE COMPOSITION OF LEAF(NEEDLE)FALL OF TREES IN CERTAIN FOREST ASSOCIATIONS IN THE KARST AREA OF WESTERN CROATIA Summary The work represents a first contribution from the territory of Croatia to the knowledge of the role and position of certain forest tree species in the process of the biological circulation of matter in forest associations. The investigation includes the determination of the percent content of N, P, K, Ca and Mg in the leaffall of Beech, Fir, Maple and Elm. For the investigations in question were avaible 18 experimental areas in the region of western Croatia (the Mountains Velebit— Kapela—Viševica) situated in Beech and Beech Fir forest associations. The soils there belong to the group of brown soils lying on pure limestones and to a smaller extent on pure dolomites. Within the zone of 400—1200m attitude a warm moderate climate, while in the regions over 1200m a snowy forest climate is prevailing. According to the established index of rainfall efficiency the whole region has a perhumid climate (P/E > 128). Results of investigations are presented in Tab. 5 and their mean values in Fig. 1. On the ground of the investigations carried out so far the following can be concluded: 1. In approximately equal ecological and other conditions in the association Fagetum croaticum abietetosum Horv. the tree species studied differ considerably from one_another in respect of the percent content of N, P, K, Ca, and Mg in leaf (needle)fall. According to the mean value of percent content of the elements determined in the leaffall the tree species have the following order of sequence: N — Fir (1:50), Elm (1:37), Maple (1:21), Beech (0:90) P — Fir (0:12), Elm (0:09), Maple (0:07), Beech (0:05) K — Elm (0:77), Fir (0:37), Maple (0:22), Beech (0:21) Ca — Elm (4:05), Maple (2.55), Beech (1:82), Fir (1:43) Mg — Maple (0:27), Elm (0:24), Fir (0:14), Beech (0:14) 2. The Beech leaffall in Beech stands of equal soil conditions (the group of brown soils on limestones and dolomites) and in various climatogenic associations is differing as to its content of N, P, K, Ca and Mg. As to individual associations these differences are considerably greater with respect to K, Ca and Mg, and very small with respect to P and N. According to the present value of the percent content of analysed elements in the Beech leaffall the investigated forest associations have the following order of sequence: N — Fagetum croat. subalpinum Horv. (0:85), Fagetum croat. montanum Horv. (0:83), Fagetum croat. seslerietosum Horv. (0:81), and Fagetum croat. abietetosum Horv. (0:80); P — Fagetum croat. abietetosum Horv. (0:05), Fagetum croat. subalpinum Horv. (0:04), Fagetum croat. montanum Horv. (0:04), Fagetum croat. seslerietosum Horv. (0:04); K — Fagetum croat. seslerietosum Horv. (0:22), Fagetum croat. abietetosum Horv. (0:21), Fagetum croat. subalpinum Horv. (0:16), and Fagetum croat. montanum Horv. (0:13); Ca — Fagetum croat. subalpinum Horv. (2:20), Fagetum croat. seslerietosum Horv. 1:91), Fagetum croat. montanum Horv. (1:85), Fagetum croat. abietetosum Horv. (1:82); Mg — Fagetum croat. montanum Horv. (0:26), Fagetum croat. seslerietosum Horv. (0:18), Fagetum croat. abietetosum Horv. (0:14), and Fagetum croat. subalpinum Horv. (0:12). 3. According to data concerning the percent content of elements determined in the leaffall in the association Fagetum croat. abietetosum Horv., and under soil conditions characterized by a group of brown soils on limestones, the studied tree species exhibit varying ameliorative capacities considering the nutrient status of the soil. In relation to Fir and Beech, Elm and Maple possess an even many times higher percent content of K, Ca, and Mg in the leaffall. Taking into consideration that the leaching of bases in the soil represents an essential pedodynamic process under the investigated conditions, it is necessary to combat this harmful process — from the standpoint of soil fertility — by maintaining and introducing into the forests and forest cultures Maple and Elm as ameliorative species with high degree of biological accumulation of K, Ca, and Mg. |