China's forests cover 208.3 million ha and span a wide range of climates and a large variety of forest types, including tropical, temperate, and boreal forests. However, the variation patterns of fine root (< 2...China's forests cover 208.3 million ha and span a wide range of climates and a large variety of forest types, including tropical, temperate, and boreal forests. However, the variation patterns of fine root (< 2 mm in diameter) biomass, production, and turnover from the south to the north are unclear. This study summarizes fine root biomass (FRB), production (FRP) and turnover rate (FRT) in China's forests as reported by 140 case studies published from 1983 to 2014. The results showed that the mean values of FRB, FRP and FRT in China's forests were 278 g m(-2), 366 g m(-2) a(-1), and 1.19 a(-1), respectively. Compared with other studies at the regional or global scales, FRB in China's forests was lower, FRP was similar to estimates at the global scale, but FRT was much higher. FRB, FRP, and FRT in China's forests increased with increasing mean annual precipitation (MAP), indicating that fine root variables were likely related to MAP, rather than mean annual temperature or latitude. This is possibly due to the small variation in temperature but greater variation in precipitation during the growing season. These findings suggest that spatiotemporal variation in precipitation has a more profound impact on fine root dynamics in China's forests, and this will impact carbon and nutrient cycles driven by root turnover in the future.展开更多
The belowground biomass is represented by coarse and fine roots. Concentrated in the superficial horizons of the soil, the fine roots play a crucial role in the functioning of a forest ecosystem. However, studies on t...The belowground biomass is represented by coarse and fine roots. Concentrated in the superficial horizons of the soil, the fine roots play a crucial role in the functioning of a forest ecosystem. However, studies on their dynamics in natural forests are almost non-existent in the Republic of Congo. Here, we estimated the biomass, production, turnover and fine root lifespan of two forest strata of a semi-deciduous forest: the <i><span style="font-family:Verdana;">Gilbertiodendron dewevrei</span></i><span style="font-family:Verdana;"> (De Wild.) J. Léonard forest (GF) and the mixed forest (MF) of land. The ingrowth cores method was used to estimate the biomass, production, turnover and lifespan of fine roots. The results of this study revealed that the biomass, production and fine root turnover of the two forest strata studied significantly decreased with increasing soil depth, with an increase in lifespan. The annual fine root biomass of GF (2284.50 ± 37.62 <img src="Edit_990c94b6-013e-4e21-90df-d1388dc0e65f.png" alt="" /></span><span style="font-family:Verdana;"> and 1034.61 ± 14.52 <img src="Edit_dff42540-5a2f-413b-8620-cb500e9961e2.png" alt="" /></span><span style="font-family:Verdana;">) was slightly lower than that of MF (2430.07 ± 40.68 <img src="Edit_66800589-8460-4c37-83b2-2df0f335d75d.png" alt="" /></span><span style="font-family:Verdana;"> and 1043.10 ± 11.75 <img src="Edit_c22f255e-d910-4b49-a6a4-033516044362.png" alt="" /></span><span style="font-family:Verdana;">) in the 0-15 cm and 15-30 cm horizons, respectively. The annual production of fine roots from these latter horizons was respectively 1300.19 ± 32.17 <img src="Edit_5482204b-8e9e-476a-907d-0865bf3a1c99.png" alt="" /></span><span style="font-family:Verdana;"> and 539.18 ± 11.55 <img src="Edit_65a2856e-5322-4fc9-b42a-3ba1176fa992.png" alt="" /></span><span style="font-family:Verdana;"> in GF and 1362.24 ± 39.59 <img src="Edit_9802e464-658d-48eb-9b57-8e746c3e8ef4.png" alt="" /></span><span style="font-family:Verdana;"> and 492.95 ± 14.38 <img src="Edit_51413fca-930c-45b9-a385-2b55d4d2bac8.png" alt="" /></span><span style="font-family:Verdana;"> in the MF. Root turnover was higher in the GF (1.68 ± 0.05 <img src="Edit_ce9d780c-6a46-46c4-aad2-653309318e29.png" alt="" /></span><span style="font-family:Verdana;"> and 1.35 ± 0.03 <img src="Edit_d66d8b7b-c608-4398-9441-e85547f03dea.png" alt="" /></span><span style="font-family:Verdana;">) than in the MF (1.57 ± 0.05 <img src="Edit_cb79094f-88a0-401c-a3e7-06eedb2cef9a.png" alt="" /></span><span style="font-family:Verdana;"> and 1.13 ± 0.02 <img src="Edit_e4f9b6d7-2e2e-44d5-8662-862b8f8ff80e.png" alt="" /></span><span style="font-family:Verdana;">). The lifespan of fine roots increased with the depth of the soil. The difference in fine root dynamics observed between the forest strata studied was influenced by the Evenness index and the above-ground biomass.</span>展开更多
基金supported by Grants from the National Key Research and Development Program of China(2016YFD06004040604)the Natural Science Foundation of Heilongjiang Province(No.C2016004)
文摘China's forests cover 208.3 million ha and span a wide range of climates and a large variety of forest types, including tropical, temperate, and boreal forests. However, the variation patterns of fine root (< 2 mm in diameter) biomass, production, and turnover from the south to the north are unclear. This study summarizes fine root biomass (FRB), production (FRP) and turnover rate (FRT) in China's forests as reported by 140 case studies published from 1983 to 2014. The results showed that the mean values of FRB, FRP and FRT in China's forests were 278 g m(-2), 366 g m(-2) a(-1), and 1.19 a(-1), respectively. Compared with other studies at the regional or global scales, FRB in China's forests was lower, FRP was similar to estimates at the global scale, but FRT was much higher. FRB, FRP, and FRT in China's forests increased with increasing mean annual precipitation (MAP), indicating that fine root variables were likely related to MAP, rather than mean annual temperature or latitude. This is possibly due to the small variation in temperature but greater variation in precipitation during the growing season. These findings suggest that spatiotemporal variation in precipitation has a more profound impact on fine root dynamics in China's forests, and this will impact carbon and nutrient cycles driven by root turnover in the future.
文摘The belowground biomass is represented by coarse and fine roots. Concentrated in the superficial horizons of the soil, the fine roots play a crucial role in the functioning of a forest ecosystem. However, studies on their dynamics in natural forests are almost non-existent in the Republic of Congo. Here, we estimated the biomass, production, turnover and fine root lifespan of two forest strata of a semi-deciduous forest: the <i><span style="font-family:Verdana;">Gilbertiodendron dewevrei</span></i><span style="font-family:Verdana;"> (De Wild.) J. Léonard forest (GF) and the mixed forest (MF) of land. The ingrowth cores method was used to estimate the biomass, production, turnover and lifespan of fine roots. The results of this study revealed that the biomass, production and fine root turnover of the two forest strata studied significantly decreased with increasing soil depth, with an increase in lifespan. The annual fine root biomass of GF (2284.50 ± 37.62 <img src="Edit_990c94b6-013e-4e21-90df-d1388dc0e65f.png" alt="" /></span><span style="font-family:Verdana;"> and 1034.61 ± 14.52 <img src="Edit_dff42540-5a2f-413b-8620-cb500e9961e2.png" alt="" /></span><span style="font-family:Verdana;">) was slightly lower than that of MF (2430.07 ± 40.68 <img src="Edit_66800589-8460-4c37-83b2-2df0f335d75d.png" alt="" /></span><span style="font-family:Verdana;"> and 1043.10 ± 11.75 <img src="Edit_c22f255e-d910-4b49-a6a4-033516044362.png" alt="" /></span><span style="font-family:Verdana;">) in the 0-15 cm and 15-30 cm horizons, respectively. The annual production of fine roots from these latter horizons was respectively 1300.19 ± 32.17 <img src="Edit_5482204b-8e9e-476a-907d-0865bf3a1c99.png" alt="" /></span><span style="font-family:Verdana;"> and 539.18 ± 11.55 <img src="Edit_65a2856e-5322-4fc9-b42a-3ba1176fa992.png" alt="" /></span><span style="font-family:Verdana;"> in GF and 1362.24 ± 39.59 <img src="Edit_9802e464-658d-48eb-9b57-8e746c3e8ef4.png" alt="" /></span><span style="font-family:Verdana;"> and 492.95 ± 14.38 <img src="Edit_51413fca-930c-45b9-a385-2b55d4d2bac8.png" alt="" /></span><span style="font-family:Verdana;"> in the MF. Root turnover was higher in the GF (1.68 ± 0.05 <img src="Edit_ce9d780c-6a46-46c4-aad2-653309318e29.png" alt="" /></span><span style="font-family:Verdana;"> and 1.35 ± 0.03 <img src="Edit_d66d8b7b-c608-4398-9441-e85547f03dea.png" alt="" /></span><span style="font-family:Verdana;">) than in the MF (1.57 ± 0.05 <img src="Edit_cb79094f-88a0-401c-a3e7-06eedb2cef9a.png" alt="" /></span><span style="font-family:Verdana;"> and 1.13 ± 0.02 <img src="Edit_e4f9b6d7-2e2e-44d5-8662-862b8f8ff80e.png" alt="" /></span><span style="font-family:Verdana;">). The lifespan of fine roots increased with the depth of the soil. The difference in fine root dynamics observed between the forest strata studied was influenced by the Evenness index and the above-ground biomass.</span>