Pre-logging vegetation | Stand information | Green Area Index | Foliar analysis |
Pre-logging vegetation
On November 24, 2022 the logging of an area 300 m around the main tower was finished. This process started in mid-July when the understorey was taken down.
The site contained stands of various age and height, but within a 1 km radius, old (110 years) and middle-aged (60-80 years) forest of about 25 m height dominate. Due to thinnings, winter storms, and bark beetle infestation (effect can be seen in the 2020 and 2021 data), the plant area index got strongly reduced througout the past years. The shrub layer was dominated by blueberry, cranberry, moss, and flowers.
In 2008 a semi-circular area with a radius of 200 m around the EC tower was thinned, reducing tree density in this area from from 857 to 428 stems ha-1 and reducing basal area with 21%, while the rest of the target area remained untouched. The average tree density in the thinned area was 370 vs 580 trees ha-1.
The information below was gathered from data from 5 so called CPs (continuous plots), each a circle with an area of 2000m2. These areas were selected carefully and they are representative for the target area (i.e. the main area wherefrom the ecosystem fluxes origin from) which is 200 m around the main tower.
Follow this link to access the full ancillary data report of Norunda provided by the ICOS ETC.
Stand information
Data is derived from all trees within the CPs with a DBH (diameter at 1.3 m) bigger than 5 cm.
basal area (m2/ha) | ||||||
---|---|---|---|---|---|---|
species | CP01 & CP02 | CP03 & CP04 | ||||
2016 | 2021 | yearly change (%) | 2018 | 2021 | yearly change (%) | |
all trees | 38.69 | 40.84 | 1.1 | 36.76 | 38.20 | 1.3 |
Pinus sylvestris L. | 29.17 | 30.61 | 1.0 | 27.48 | 28.54 | 1.3 |
Picea abies L. | 9.25 | 9.94 | 1.5 | 9.28 | 9.66 | 1.4 |
Betula pubescens L. | 0.27 | 0.29 | 1.8 | - | - | - |
height (m) (average and standard deviation) | ||||||
---|---|---|---|---|---|---|
species | CP01 & CP02 | CP03 & CP04 | ||||
2016 | 2021 | annual change (%) | 2018 | 2021 | annual change (%) | |
all trees | 21.8(7.5) | 23.0(7.7)) | 1.1 | 21.4(8.2)) | 21.9(8.1) | 0.9 |
Pinus sylvestris L. | 26.1(2.5) | 27.4(2.4) | 1.0 | 26.4(2.4) | 27.0(2.2) | 0.7 |
Picea abies L. | 16.3(8.3) | 17.4(8.5) | 1.3 | 15.7(8.7) | 16.1(8.6) | 1.0 |
Betula pubescens L. | 19.3(2.9) | 20.6(4.0) | 1.3 | - | - | - |
DBH (m) (average and standard deviation) | ||||||
---|---|---|---|---|---|---|
species | CP01 & CP02 | CP03 & CP04 | ||||
2016 | 2021 | yearly change (%) | 2018 | 2021 | yearly change (%) | |
all trees | 0.28(0.11) | 0.29(0.11)) | 0.7 | 0.26(0.12)) | 0.27(0.12) | 0.9 |
Pinus sylvestris L. | 0.34(0.05) | 0.35(0.06) | 0.5 | 0.34(0.05) | 0.35(0.05) | 0.6 |
Picea abies L. | 0.20(0.11) | 0.21(0.11) | 1.1 | 0.18(0.11) | 0.19(0.11) | 1.3 |
Betula pubescens L. | 0.18(0.03) | 0.19(0.03) | 0.8 | - | - | - |
*Only 6 trees.
Green area index (GAI)
GAI (m2 green per m2 soil) was derived from digital hemisperical pictures that were taken with a fish-eye lense in four CPs. GAI was calculated at each location (9 per plot) and averaged per plot. Only quality checked pictures were included.
overstory GREEN area index | ||||
---|---|---|---|---|
date | mean GAI (m2/m2) | standard deviation (m2/m) | clumping factor | |
2019 | May | 2.24 | 0.24 | 0.922 |
Jun | 2.76 | 0.49 | 0.939 | |
Sep | 2.77 | 0.52 | 0.935 | |
Nov | 2.73 | 0.53 | 0.934 | |
2020 | Jan | 1.01 | 0.48 | 0.970 |
Dec | 2.78 | 0.63 | 0.932 | |
2021 | Nov (CP2&4) | 3.00 | 0.28 | 0.938 |
Foliar analyses
This information bases on a chemical analysis of 2x15 trees in two of the CPs; in total 23 pine and 7 spruces trees. Needles were gathered from the south-facing uppermost third of the crown, and then analyzed for different nutrients (g per kg dry matter DM).
Foliar analyses | ||||||
---|---|---|---|---|---|---|
parameter | species | 03/2018 | 01/2019 | 01/2020 | 03/2021 | 03/2022 |
Ca (g/kgDM) | Picea abies L. | 4.45 | 5.71 | 6.22 | 4.06* | 6.78 |
Pinus sylvestris L. | 2.86 | 2.95 | 2.80 | 2.50 | 2.67 | |
Cu (g/kgDM) | Picea abies L. | 1.41 | 1.38 | 1.86 | 1.68* | 1.15 |
Pinus sylvestris L. | 3.62 | 2.53 | 2.87 | 2.81 | 2.58 | |
Fe (g/kgDM) | Picea abies L. | 7.82 | 11.83 | 13.71 | 36.88* | 16.37 |
Pinus sylvestris L. | 20.03 | 26.13 | 37.44 | 64.13 | 21.07 | |
Mg (g/kgDM) | Picea abies L. | 1.13 | 1.18 | 1.12 | 1.02* | 1.03 |
Pinus sylvestris L. | 0.89 | 1.08 | 1.06 | 1.02 | 1.00 | |
Mn (g/kgDM) | Picea abies L. | 203.21 | 290.57 | 465.86 | 250.17* | 727.86 |
Pinus sylvestris L. | 175.74 | 159.17 | 238.17 | 198.91 | 177.61 | |
C (g/kgDM) | Picea abies L. | 510.57 | 511.00 | 502.29 | 672.33* | 498.71 |
Pinus sylvestris L. | 526.48 | 532.22 | 520.91 | 694.09 | 521.57 | |
N (g/kgDM) | Picea abies L. | 9.90 | 10.46 | 10.52 | 13.75* | 10.70 |
Pinus sylvestris L. | 13.67 | 14.11 | 14.90 | 19.17 | 12.71 | |
P (g/kgDM) | Picea abies L. | 1.26 | 1.35 | 1.31 | 1.40* | 1.35 |
Pinus sylvestris L. | 1.39 | 1.56 | 1.61 | 1.59 | 1.50 | |
K (g/kgDM) | Picea abies L. | 5.58 | 5.97 | 5.82 | 7.17* | 5.43 |
Pinus sylvestris L. | 5.50 | 6.06 | 6.21 | 6.42 | 6.06 | |
Zn (g/kgDM) | Picea abies L. | 31.89 | 30.26 | 52.03 | 38.88* | 42.61 |
Pinus sylvestris L. | 33.45 | 31.39 | 40.03 | 40.00 | 33.19 |