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outliers in the data set. Median P values in the different nutrition classes of the young trees were much higher than those for mature trees in spruce, somewhat higher in young than mature trees in beech and oak, but no difference was observed between the mature and young pine trees for their foliar P concentrations. In all cases, the experimental plants had higher P concentrations than the mature and young trees, except for beech where the number of cases was too low to for a comparison. This variability in foliar P concentrations with tree age is an important factor to consider, when the foliar samples for the next nationwide forest soil survey (BZE-II) are taken. Table 2: Foliar P data of mature, young and experimental trees as described by van den Burg. Statistical parameters are provided for the optimum growth class (class 6+6.5) and the values are given in mg/g. (n refers to the number of individual cases included, sd = standard deviation). Species Age n mean sd median min max Spruce Mature 151 1.78 0.43 1.70 1.10 2.90 Young 52 2.38 0.57 2.25 1.40 3.80 Experiments 62 2.48 0.64 2.50 1.00 3.80 Pine Mature 112 1.72 0.41 1.60 1.00 3.30 Young 74 1.66 0.34 1.60 0.90 2.70 Experiments 42 1.96 0.43 2.00 1.00 3.10 Beech Mature 25 1.52 0.16 1.50 1.20 1.90 Young 32 1.73 0.57 1.70 0.80 3.00 Experiments 4 1.18 0.26 1.25 0.80 1.40 Oak Mature 43 1.81 0.44 1.70 1.20 2.80 Young 62 2.01 0.53 1.85 0.90 3.00 Experiments 8 2.00 0.34 2.00 1.50 2.50 Needle age and foliage condition Commonly older needles from previous years have lower concentration of P than the current year needles. The difference in the P concentrations of current and older needles depends upon the ages of the needles being compared, the P status of the site and genetically controlled factors driving withdrawal patterns of the stand. For 24
example the compiled data from BZE-I sites for spruce showed that 3-year old spruce needles had 30 to 40 % lower values of P than the fully developed needles from the current year (Fig 1). The difference between 1 st - and 3 rd year needles were surprisingly constant across the whole range of needle P concentrations in spruce (BMLEF 1997). In another data set shown in Table 5, foliar P levels in ten spruce stands were measured continuously for 10 years. Three years old needles had 66 to 82 % of P present in the one year old needles. Five year old needles had further reduced P levels (range 47% to 70%). The amount of P re-allocated from 5 year old needles to the youngest cohort of needles equated to 30 to 50 % of the content in the current year needles. The withdrawal was not related to any measured site property. Similar results were also obtained for one and two years old needles of Scots pine. Soil characteristics In a study of 49 stands of European beech (60-or more years-old) in the Werdenfelser Land region where the canopy conditions were monitored, Ewald (2000) analysed foliage and soil samples from 8 sites for nutrient composition. Sites could be divided into 2 groups. Moderate P levels were found in trees from well-developed mineral soils, and extremely low P levels (0.6-1.0 mg/g) in immature carbonate soils where total P levels in soils were low and Ca saturation very high. Very high N/P ratios of 30 or more were associated with low P levels. Phosphorus was a critical element in the nutrition of beech in the calcareous Alps, which may be partly responsible for poor vitality of this species in mixed mountain forests. Foliar P values in beech forests on calcareous bedrocks are commonly low when compared to acid soils. As the availability of protons is required to release P from rock minerals it is possible that low foliar P values on calcareous bedrock may result from the high buffering of most of the protons by carbonates which renders less protons available for silicate weathering. Highest values of foliar P are found in spruce and pine stands on bedrocks of basalt type (bedrock type 8 – median value of P in the current needles of 1.5 mg P/g) and the lowest on the calcareous type (bedrock type 1 – median values were 1.2 mg/g for spruce and 1.3 mg/g for pine (BMELF 1997). 25
Page 1 and 2: ASSESSMENT OF CHANGES IN THE PHOSPH
Page 3 and 4: RECOMMENDATIONS 1. The results of t
Page 5 and 6: EXECUTIVE SUMMARY 1. The first nati
Page 7 and 8: High N inputs and uptake by plants
Page 9 and 10: 12. It is recommended that a series
Page 11 and 12: Below, these hypotheses are being d
Page 13 and 14: Douglas fir which suffered from abs
Page 15 and 16: easons of such results. Another rea
Page 17 and 18: The frequency and the amount of mas
Page 19 and 20: usually present in the leaves. In v
Page 21 and 22: level class are given in brackets.
Page 23: 2.3 Factors influencing the foliage
Page 27 and 28: mostly during periods of active gro
Page 29 and 30: Table 3: Number of cases included f
Page 31 and 32: P % 0.1 0.2 0.3 0.4 Kiefer 4 4,5 5
Page 33 and 34: P % 0.1 0.2 0.3 0.4 0.5 Eiche 4 4,5
Page 35 and 36: 19.84 n=144 NVHU< 1228 | CMENGE< 38
Page 37 and 38: 2.6 Changes in P concentrations in
Page 39 and 40: in section 1 of this report. In sum
Page 41 and 42: Fig 8: Mixed linear model describin
Page 43 and 44: Fig 10: . Mixed linear model descri
Page 45 and 46: Table 6: Concentration of P (mg/g)
Page 47 and 48: (Nilsen and Abrahmsen 2003) reporte
Page 49 and 50: 3. PHOSPHRUS IN FOREST SOILS 3.1 In
Page 51 and 52: sequential extraction scheme of ext
Page 53 and 54: Table 8 : Sequential extraction pro
Page 55 and 56: phosphates at pH values
Page 57 and 58: 3.2.2 Inorganic forms of P - desorp
Page 59 and 60: Mineralisation of organic P does no
Page 61 and 62: enhances the dissolution of Ca-phos
Page 63 and 64: water, and sodium bicarbonate metho
Page 65 and 66: Table 10. Estimated transfers and c
Page 67 and 68: 3.3 Use of pedo-transfer functions
Page 69 and 70: the amount taken up at each site. T
Page 71 and 72: is commonly saturated with HCO3 is
Page 73 and 74: assess P status or any changes in P
Page 75 and 76:
Forest Ecol. Manage. 92, 119-152. B
Page 77 and 78:
Rev. Plant Physiol.Plant Mol. Biol.
Page 79 and 80:
and N-free-fertilisation. Plant Soi
Page 81 and 82:
Sparling GP, Hart PBS, August JA. (
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