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Biomass dynamics in young silver birch stands on post-agricultural lands in Central Poland

100%

Zasada M., Bijak S., Bronisz K., Bronisz A., Gaweda T.

Drewno. Prace Naukowe. Doniesienia. Komunikaty

2014

tom 57

nr 192

The paper analyses the production and allocation of biomass in young, spontaneoussilver birch afforestation occurring on post-agricultural lands in the Mazowszeregion (central Poland). We investigated 114 sample plots of age varying from 1 to 19 years. During the first 15 years after their establishment on abandoned farmland, the naturally regenerated silver birch stands produced on average approximately 75 tons of dry biomass per hectare. The major (50–70%) part of this biomass was stored in the tree stems and this share increased with age. The fractions of biomass in the foliage and roots decreased over time, while the share of biomass in the branches remained rather constant. The significant age-dependency of the allometric relationships suggested the need to use age-sensitive biomass expansion factors to estimate the biomass from the stem volume.

Biomass dynamics of fishing in estuarine lakes Lebsko and Sarbsko

80%

Orzechowski B., Obolewski K.

Baltic Coastal Zone. Journal of Ecology and Protection of the Coastline

2008

tom 12

The research has shown the domination of fluctuative trends in the biomass dynamics for a major-ity of the caught fish species and decrease in the stocks of littoral phytophil fish. The main reason of the fishery breakdown of the pike perch in Łebsko and perch in Sarbsko was exploitation at a too big scale. The resources of the mentioned fish populations were drastically violated in the first decade of the 47 years of exploitation, that is in the years: 1952-1999. However, the highest fishing level of most of the fish species in annual cycles was achieved notoriously at spawning pe-riods during the whole 47 years. It just goes to show a complete ignorance of valid periods and the protective dimensions in the fishery practice. In the consecutive decades and for all the 47 years, the position and the degree of mass dominance for separate species of fish in fishing have been es-tablished. Pairs of superdominants and eudominants with the greatest quantitative participation in fishing have been distinguished for each of the lake. For the regeneration of the pike’s, the tench’ and the crucian carp’ population fishing of those species should be banned for the time of their generation. Reduction to small Cyprynidae species should be conducted by intensive stock in Łebsko with the pike and in Sarbsko with the pike-perch.

Ograniczanie wyników

1 Baltic Coastal Zone. Journal of Ecology and Protection of the Coastline

1 Drewno. Prace Naukowe. Doniesienia. Komunikaty

1 Bijak S.

1 Bronisz A.

1 Bronisz K.

1 Gaweda T.

1 Obolewski K.

1 Orzechowski B.

1 Zasada M.

1 2014

1 2008

Wyniki wyszukiwania

Biomass dynamics in young silver birch stands on post-agricultural lands in Central Poland

Biomass dynamics of fishing in estuarine lakes Lebsko and Sarbsko