Species | Regression equations | Step no. | Variable entered | R2 | Change in R2 (%) | P value |
---|---|---|---|---|---|---|
2007 | ||||||
S. krylovii | LL = –3·39Pnet + 70·89 | 1 | Pnet | 0·805 | 80·5 | <0·001 |
A. cristatum | LL = –1·11LNC – 3·12Pnet + 103·65gs + 86·69 | 1 | LNC | 0·779 | 77·9 | <0·001 |
2 | Pnet | 0·883 | 10·4 | <0·001 | ||
3 | gs | 0·943 | 6·0 | <0·001 | ||
C. squarrosa | LL = –0·49LNC + 43·67 | 1 | LNC | 0·790 | 79·0 | <0·001 |
P. tanacetifolia | LL = –1·84SPAD + 121·27 | 1 | SPAD | 0·713 | 71·3 | <0·001 |
M. ruthenica | LL = –2·63SPAD + 191·18 | 1 | SPAD | 0·830 | 83·0 | <0·001 |
2008 | ||||||
S. krylovii | LL = –3·43Pnet + 109·27 | 1 | Pnet | 0·683 | 68·3 | <0·001 |
A. cristatum | LL = 1·64C/N – 24·84gs + 0·19DMC – 54·59 | 1 | C/N | 0·722 | 72·2 | <0·001 |
2 | gs | 0·913 | 19·1 | <0·001 | ||
3 | DMC | 0·955 | 4·2 | <0·001 | ||
C. squarrosa | LL = –0·74LNC + 0·06DMC + 28·58 | 1 | LNC | 0·855 | 85·5 | <0·001 |
2 | DMC | 0·927 | 7·2 | <0·001 | ||
P. tanacetifolia | LL = –1·76SPAD + 0·15DMC + 73·84 | 1 | SPAD | 0·701 | 70·1 | <0·001 |
2 | DMC | 0·835 | 13·4 | <0·001 | ||
M. ruthenica | LL = 7·08δ13C – 1·19SPAD + 314·61 | 1 | δ13C | 0·564 | 56·4 | <0·01 |
2 | SPAD | 0·735 | 17·1 | <0·01 |
LL, leaf longevity; Pnet, net photosynthetic rate based on area; gs, stomatal conductance; LNC, leaf nitrogen content; SPAD, estimated leaf chlorophyll concentration; C/N ratio, ratio of leaf carbon to nitrogen contents; DMC, leaf dry matter content; δ13C, leaf carbon isotopic composition.