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Relationship between forest canopy and natural regeneration in the subalpine spruce-larch forest (north-east Italy)

100%

Marchi A., Paletto A.

Folia Forestalia Polonica. Series A . Forestry

2010

tom 52

nr 1

The authors describe the difference between canopy cover (proportion of the forest floor covered by the vertical projection of the tree crowns) and canopy closure (proportion of sky hemisphere obscured by vegetation when viewed from a single point) and the respective ground-based estimation techniques focused on two types of densiometer (GRS tube and spherical). The data collected in the field were used to analyse the relationship between forest canopy and natural regeneration in two subtypes of subalpine larch-spruce forests. The results indicate that in the first subtype characterized by a high fertility and a high canopy cover (around 62%), the level of natural regeneration is low (115 stems per hectare) and it is nearly exclusively composed by spruce [Picea abies (L.) Karst.]. For the second subtype characterized by a low fertility and a medium canopy cover (around 49%) the natural regeneration is rather dense (650 stems per hectare). At last the authors evidence a insignificant difference between the data of forest canopy collected by different ground-based estimation techniques (+0.7% using spherical densiometer compared to using GRS tube densiometer).

Riparian vegetation of streams and the macroinvertebrate community structure

80%

Bis B., Higler L. W. G.

International Journal of Ecohydrology and Hydrobiology

2001

tom 01

nr 1-2

Riparian vegetation is a typical ecotone by its structural and functional position between the terrestial part of the watershed and the stream (Naiman, Decamps 1990). In consequence, the riparian zone forming an integrated component of stream ecosystems significantly determines the aquatic community. Macroinvertebrates are affected by defined variability of environmental factors. In streams under canopy: light access is reduced; summer temperatures are lower; shed leaves form the main source of energy; insects falling from the vegetation into the water create another source of food; roots from trees form shelter and strongly influence hydraulic patterns. As a result, many (micro) habitats can exist and persist. The relationships between the covered percentage of the riparian zone, hydraulic processes, POM retention and macroinvertebrate functional organization was analyzed. Riparian vegetation forms a buffer zone in agricultural landscape and thus prevents inflow of nutrients, but also of fine sediments. Clearing of riparian vegetation changes all these conditions, resulting in a totally different and less varied biocommunity. Examples are given from Poland and The Netherlands.

Ograniczanie wyników

1 Folia Forestalia Polonica. Series A . Forestry

1 International Journal of Ecohydrology and Hydrobiology

1 Bis B.

1 Higler L. W. G.

1 Marchi A.

1 Paletto A.

1 2010

1 2001

Wyniki wyszukiwania

Relationship between forest canopy and natural regeneration in the subalpine spruce-larch forest (north-east Italy)

Riparian vegetation of streams and the macroinvertebrate community structure