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Foliar N concentration and δ 15 N signature reflect the herb layer species diversity and composition in oak‐dominated forests
Author(s) -
Hofmeister Jeňýk,
Hošek Jan,
Bůzek František,
Roleček Jan
Publication year - 2012
Publication title -
applied vegetation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.096
H-Index - 64
eISSN - 1654-109X
pISSN - 1402-2001
DOI - 10.1111/j.1654-109x.2011.01174.x
Subject(s) - herb , nutrient , vegetation (pathology) , canopy , composition (language) , species diversity , ecosystem , agronomy , botany , biology , environmental science , ecology , medicinal herbs , medicine , linguistics , philosophy , pathology , traditional medicine
Questions Is the herb layer species diversity and composition in species‐rich oak‐dominated forests related to the (i) soil nitrogen (N) pool, (ii) foliar N concentration, and (iii) foliar 15 N/ 14 N isotope ratio (δ 15 N), as indicators of the N status in ecosystems? How do they correspond to the E llenberg indicator value for N ( EIV ‐N) of the herb layer vegetation? Location Three areas in central B ohemia ( C zech R epublic) underlain by different geological substrates. Methods We assessed the herb layer species composition in nine oak‐dominated forests growing on different substrates, in relation to both soil nutrient pools and oak leaf nutrient concentrations. Data on the herb layer vegetation composition were collected in 16 square plots (25 m 2 each) distributed according to a fixed stratified random design at each site. Soil nutrient pools were calculated on the basis of nutrient concentration and weight of quantitative soil samples taken from six defined depth strata at each of two or three 0.5‐m 2 pits at each site. Foliar analyses were based on samples of 150 leaves from the upper part of the canopy of five oaks at each site. Results The mean S hannon diversity index of herb layer vegetation was negatively related to the mean foliar N tot. concentration, whereas the mean recovery rate ( RR ) of herb layer species was strongly positively related to foliar δ 15 N signatures and, less markedly, to the soil N tot. pool. Similarly, both the foliar δ 15 N and the soil N tot. pool were positively correlated with mean‐weighted EIV ‐N in the herb layer vegetation. Conclusions The herb layer species diversity and composition was significantly related to N availability at our study sites. Foliar N concentration and the δ 15 N signature may reliably indicate: (i) the current N status of oak‐dominated forests, in accordance with previous published findings; and (ii) the consequences of that N status for the herb layer species diversity and composition. Foliar δ 15 N may also be used to detect the susceptibility of an ecosystem to the spread of a few species with high colonization ability in the herb layer, at the expense of other forest species.