@misc{Aulak_Władysław_Błędy_1974,
 author={Aulak, Władysław},
 editor={Polska Akademia Nauk. Komitet Ekologiczny},
 copyright={Creative Commons Attribution BY 3.0 PL license},
 address={Warszawa},
 howpublished={online},
 year={1974},
 language={pol},
 abstract={The author analyzes methods of indirect estimation of net herb layer production based on states of biomass. Analyses were made for three basic development types of herb layer, i.e. annual plants (I), evergreen plants (II) and biennials and perenniels (III). Parameters affecting the extent of errors in estimating production are defined for the method of maximum state of biomass, difference in maximum and minimum and according to the sum total of differences in states of biomass between the different observation times (Fig. 1, Tab. I). In the above methods errors occur due to the existence in the state of biomass during the given year of matter produced in previous years (for development types II and III). Additional errors in defining production by methods based on state of biomass result from a lack of knowledge of changes taking place in populations of different species between observation times. There is for instance because of no knowledge of elimination, production of newly-formed individuals and production by individuals not eliminated during the given period. This results in discrepancies between production estimated by the above methods and real production (Fig. 2, Tab. II). The author suggests that it is essential to carry out observations on permanent control areas, on which analysis can be made of changes in the state of each individual in a population in order to define the errors in each of the methods of indirect assessment of production. This is necessary as these methods, as being fairly quick, will continue to be applied both for production estimation and to definition of zero resources of ecosystems for herbivores.},
 title={Błędy metod szacowania produkcji runa leśnego opartych na stanach biomas},
 type={Text},
 URL={http://rcin.org.pl./Content/147205/PDF/WA058_105696_P3259-20-Eko-Pol-B.pdf},
 volume={20},
 number={1},
 journal={Wiadomości Ekologiczne},
 publisher={Państwowe Wydawnictwo Naukowe},
 keywords={biological productivity, productivity, biological, ground cover plants, groundcover},
}