Table 1 The proportional contribution of different N forms to plant N uptake in forest trees by using the 15N natural abundance method
Study sites | Ecosystem | MAT (°C) | Vegetations | Treatment | Proportional contribution (%) | References | ||
|---|---|---|---|---|---|---|---|---|
NH4+ | NO3− | DON | ||||||
Hawaii | Tropical forest | 16 | Metrosideros polymorpha | 2200 mm (MAP) | 15 | 80 | 5 | Houlton et al. (2007) |
Cheirodendron trigynum | 2450 mm | 17 | 78 | 5 | Houlton et al. (2007) | |||
Cibotium glaucum | 2750 mm | 15 | 80 | 5 | Houlton et al. (2007) | |||
Melicope clusiifolia | 3350 mm | 5 | 93 | 2 | Houlton et al. (2007) | |||
4050 mm | 93 | 5 | 2 | Houlton et al. (2007) | ||||
5050 mm | 93 | 5 | 2 | Houlton et al. (2007) | ||||
Japan-Norikura | Forest | 8.7 | Chamaecyparis obtusa | Norikura-A | 100 | 0 | Takebayashi et al. (2010) | |
Norikura-B | 95 | 5 | Takebayashi et al. (2010) | |||||
Norikura-C | 94 | 6 | Takebayashi et al. (2010) | |||||
Norikura-A | 48 | 38 | 14 | Takebayashi et al. (2010) | ||||
Norikura-B | 47 | 39 | 14 | Takebayashi et al. (2010) | ||||
Norikura-C | 28 | 47 | 25 | Takebayashi et al. (2010) | ||||
Japan-Okutama | Forest | 14.3 | Chamaecyparis obtusa | Okutama-A | 100 | 0 | Takebayashi et al. (2010) | |
Okutama-B | 47 | 53 | Takebayashi et al. (2010) | |||||
Okutama-A | 46 | 40 | 14 | Takebayashi et al. (2010) | ||||
Okutama-B | 24 | 61 | 15 | Takebayashi et al. (2010) | ||||
Japan-Hachioji | Forest | 14.8 | Chamaecyparis obtusa | Hachioji-A | 39 | 61 | Takebayashi et al. (2010) | |
Hachioji-B | 0 | 100 | Takebayashi et al. (2010) | |||||
Hachioji-A | 20 | 67 | 13 | Takebayashi et al. (2010) | ||||
Hachioji-B | 3 | 95 | 2 | Takebayashi et al. (2010) | ||||
Panama | Lowland tropical rainforest | 27 | Alseis blackiana | 56 | 44 | Mayor et al. (2014) | ||
Heisteria concinna | 43 | 57 | Mayor et al. (2014) | |||||
Tetragastris panamensis | 70 | 30 | Mayor et al. (2014) | |||||
Oenocarpus mapora | 30 | 70 | Mayor et al. (2014) | |||||
Southwest China | Plantations | 8.9 | Picea asperata | 20-year-old | 27 | 73 | Zhang et al. (2018) | |
30-year-old | 42 | 58 | Zhang et al. (2018) | |||||
40-year-old | 100 | 0 | Zhang et al. (2018) | |||||
50-year-old | 93 | 7 | Zhang et al. (2018) | |||||
70-year-old | 100 | 0 | Zhang et al. (2018) | |||||
20-year-old | 19 | 43 | 38 | Zhang et al. (2018) | ||||
30-year-old | 31 | 46 | 23 | Zhang et al. (2018) | ||||
40-year-old | 34 | 30 | 36 | Zhang et al. (2018) | ||||
50-year-old | 33 | 33 | 34 | Zhang et al. (2018) | ||||
70-year-old | 43 | 18 | 39 | Zhang et al. (2018) | ||||
Northeast China | Greenhouse study | 22.4 | Pinus koraiensis | 33 | 24 | 43 | Zhu et al. (2019) | |
Larix kaempferi | 6 | 74 | 20 | Zhu et al. (2019) | ||||
Quercus mongolica | 1 | 88 | 11 | Zhu et al. (2019) | ||||
Juglans mandshurica | 11 | 68 | 21 | Zhu et al. (2019) | ||||
Northeast China | Temperate forest | 2.7 | Pinus koraiensis | 37 | 63 | This study | ||
Picea koraiensis | 18 | 82 | This study | |||||
Pinus sylvestris | 40 | 60 | This study | |||||
Larix olgensis | 27 | 73 | This study | |||||
Pinus koraiensis | 19 | 53 | 28 | This study | ||||
Picea koraiensis | 23 | 48 | 29 | This study | ||||
Pinus sylvestris | 28 | 47 | 25 | This study | ||||
Larix olgensis | 27 | 43 | 30 | This study | ||||