Table 1.
Metrics used to estimate date of senescence across publications reporting the date of fall leaf senescence in the northern hemisphere (DOS studies only, n = 56 publications and 861 independent measurements total)
| Leaf senescence metric | No. of publications | Fraction of publications | No. of observations | Fraction of observations |
|---|---|---|---|---|
| 50 % leaf fall | 20 | 0·36 | 291 | 0·34 |
| 100 % leaf fall | 12 | 0·21 | 162 | 0·19 |
| NDVI | 6 | 0·11 | 83 | 0·1 |
| 80 % leaf fall | 4 | 0·07 | 62 | 0·07 |
| 50 % green | 3 | 0·05 | 3 | 0 |
| 50 % colour change | 2 | 0·04 | 7 | 0·01 |
| 0 % green | 2 | 0·04 | 2 | 0 |
| 50 % yellow | 2 | 0·04 | 3 | 0 |
| PAR transmission plateau | 2 | 0·04 | 66 | 0·08 |
| Peak colour change | 2 | 0·04 | 94 | 0·11 |
| Start of leaf fall | 2 | 0·04 | 68 | 0·08 |
| 10 % colour change in 10 % of trees | 1 | 0·02 | 8 | 0·01 |
| 10 % colour change in 90 % of trees | 1 | 0·02 | 8 | 0·01 |
| 10 % leaf fall | 1 | 0·02 | 48 | 0·06 |
| 50 % Amax | 1 | 0·02 | 6 | 0·01 |
| 50 % colour change or leaf fall | 1 | 0·02 | 103 | 0·12 |
| 75 % leaf fall | 1 | 0·02 | 9 | 0·01 |
| 90 % leaf fall | 1 | 0·02 | 9 | 0·01 |
| Eddy covariance | 1 | 0·02 | 2 | 0 |
| Landsat 50 % cover | 1 | 0·02 | 1 | 0 |
| More yellow than green leaves | 1 | 0·02 | 4 | 0 |
| Photo ‘greenness’ index | 1 | 0·02 | 1 | 0 |
| Photosynthetic rate = 0 | 1 | 0·02 | 16 | 0·02 |
| Peak red | 1 | 0·02 | 1 | 0 |
The number and total percentage of published studies and independent observations that used each metric are reported.
Note that many studies employed multiple metrics, therefore the number of entries in the table is greater than the total number of publications included in Appendix 1.
See Appendix 1 for list of publications included here.
LAI, leaf area index; PAR, photosnthetically acive radiation; NDVI, normalized difference vegetation index.