TY - JOUR

T1 - Relationship between pH-values and nutrient availability in forest soils - the consequences for the use of ecograms in forest ecology

AU - Hardtle, Werner

AU - von Oheimb, Goddert

AU - Friedel, Agnes

AU - Westphal, Christina

AU - Hartmut, Meyer

N1 - Literaturverz. S. 141 - 142

PY - 2004/1/1

Y1 - 2004/1/1

N2 - Measurements of the soil pH are often used to characterize the nutritional conditions for the vegetation at a particular site, for example in ecograms describing the ecological behaviour of a (tree) species. In spite of this use and interpretation of pH measurements, certain prerequisites must be fulfilled when pH-values are to be used as an expression of the nutritional conditions for plants. Our study in deciduous forests of northern Germany shows that in strongly acid soils (pH < 4) the correlations between pH-values on the one hand and S-value, base saturation and C/N-ratios on the other hand are generally low, particularly for measurements in the upper mineral horizon. By contrast, in moderately acid to neutral soils (pH 4-7), pH-values could be employed as a useful indicator of the nutritional conditions for the vegetation. The main reason for the observed discrepancy in the indicator quality of pH measurements is the presence of distinct differences in the cation exchange capacity (CEC) of the soils, which are often not taken into account when interpreting pH measurements. CEC-values close to zero may be associated with either low or comparatively high pH-values, depending on whether or not the few available cation exchange sites are occupied by protons or bases, respectively. In general, pH - S-value/base saturation/CN-ratio relationships are stronger in soil samples taken in the main (fine and coarse) root horizon than in those from the upper mineral horizon. Consequently, ecograms give a more precise description of vegetation-site relationships if the considered nutrient gradients refer to appropriate soil parameters (e.g. S-value, C/N-ratio) and to measurements in the main root horizon.

AB - Measurements of the soil pH are often used to characterize the nutritional conditions for the vegetation at a particular site, for example in ecograms describing the ecological behaviour of a (tree) species. In spite of this use and interpretation of pH measurements, certain prerequisites must be fulfilled when pH-values are to be used as an expression of the nutritional conditions for plants. Our study in deciduous forests of northern Germany shows that in strongly acid soils (pH < 4) the correlations between pH-values on the one hand and S-value, base saturation and C/N-ratios on the other hand are generally low, particularly for measurements in the upper mineral horizon. By contrast, in moderately acid to neutral soils (pH 4-7), pH-values could be employed as a useful indicator of the nutritional conditions for the vegetation. The main reason for the observed discrepancy in the indicator quality of pH measurements is the presence of distinct differences in the cation exchange capacity (CEC) of the soils, which are often not taken into account when interpreting pH measurements. CEC-values close to zero may be associated with either low or comparatively high pH-values, depending on whether or not the few available cation exchange sites are occupied by protons or bases, respectively. In general, pH - S-value/base saturation/CN-ratio relationships are stronger in soil samples taken in the main (fine and coarse) root horizon than in those from the upper mineral horizon. Consequently, ecograms give a more precise description of vegetation-site relationships if the considered nutrient gradients refer to appropriate soil parameters (e.g. S-value, C/N-ratio) and to measurements in the main root horizon.

KW - Biology

KW - Acidophytic forests

KW - Fagus sylvatica

KW - forest soils

KW - Northern Germany

KW - root horizons

KW - soil parameters

KW - Chemistry

KW - acidophytic forests

KW - fagus sylvatica

KW - forest soils

KW - northern germany

KW - root horizons

KW - soil parameters

UR - http://www.scopus.com/inward/record.url?scp=1942537070&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/508e2ffe-e232-35a7-bf07-d670eb2e8a2a/

U2 - 10.1078/0367-2530-00142

DO - 10.1078/0367-2530-00142

M3 - Journal articles

VL - 199

SP - 134

EP - 142

JO - Flora

JF - Flora

SN - 0367-2530

IS - 2

ER -