Effects of forest canopy gap on biomass of seedlings and its allocation in subalpine coniferous forests of western Sichuan

Abstract

Using a strip transect sampling method, the density, height (≤100 cm), basal diameter and components of biomass of Abies faxoniana seedlings, living in a forest gap (FG) and under the forest canopy (FC) of subalpine natural coniferous forests in western Sichuan, were investigated and the relationships among different components of biomass analyzed. The results indicated that the density and average height (H) of A. faxoniana seedlings were significantly different in the FG and under the FC, with the values being 12903 and 2017 per hm², and 26.6 and 24.3 cm. No significant differences were found in the average basal diameter (D) and biomass. The biomass allocation in seedling components was significantly affected by forest gap. In the FG, the biomass ratio of branch to stem reached a maximum of 1.54 at age 12 and then declined and fluctuated around 0.69. Under the FC, the biomass ratio of branch to stem increased with seedling growth and exceeded 1.0 at about age 15. The total biomass and the biomass of leaves, stems, shoots and roots grown in the FG and under the FC were significantly correlated with D²H. There were significant and positive correlations among the biomass of different components.

References

1. Beckage B Clark J S Clinton B D Haines B L 2000 A long-term study of tree seedling recruitment in southern applicationforests: The effects of canopy gaps and shrub understoriesCan J For Res30(10)16171631. doi:10.1139/cjfr‐30‐10‐1617
2. Bungard R A Scholes J D Press M C 2000 The influence of nitrogen on rain forestdipterocarp seedling exposed to a large increase in irradiancePlant Cell Environ23(11)11831194. doi:10.1046/j.1365‐3040.2000.00642.x
3. Diaci J 2002 Regeneration dynamics in a Norway spruce plantation ona silver fir-beech forest site in the SlovenianFor Ecol Manage161(1–3)2738. doi:10.1016/S0378‐1127(01)00492‐3
4. Gardiner E S Hodges J D 1998 Growth andbiomass distribution of cherrybark oak (Quercuspagoda Raf.) seedlings as influenced by light availability.For Ecol Manage108(1–2)127134. doi:10.1016/S0378‐1127(98)00220‐5
5. Guo K Werger M J A 1999 Differentresponses to shade of evergreen and deciduous oak seedlings and theeffect of acorn sizeActa Oecol20(6)579586. doi:10.1016/S1146‐609X(99)00103‐4
6. Howe H F 1990 Survival and growth of juvenile Virola surinamensis in Panama: Effects of herbivory andcanopy closureJ Trop Ecol6(3)259280
7. King D A 1994 Influence of light level on the growth and morphology ofsaplings in a Panamanian forestAmer J Bot81(8)948957. doi:10.2307/2445287
8. Lyr H Garbe V 1995 Influenceof root temperature on growth of Pinus sylevestris, Fagus sylvatica, Tilia cordata and Quercus roburTrees9(4)220223. doi:10.1007/BF00195276
9. Minotta G Pinzauti S 1996 Effects oflight and soil fertility on growth, leaf chlorophyll content and nutrientuse efficiency of beech (Fagus sylvatica L.) seedlings.For Ecol Manage86(1–3)6171. doi:10.1016/S0378‐1127(96)03796‐6
10. Norgren O 1996 Growth analysis of Scots pine and lodgepole pine seedlingsFor Ecol Manage86(1–3)1526. doi:10.1016/S0378‐1127(96)03800‐5
11. Sang W G Li J W 1998 Dynamics modelingof Korean pine forest in southern lesser Xingan mountains of ChinaActa Ecol Sin18(1)3847 (in Chinese)
12. Shen Z H Li D X Wang G F 2001 Studies on the gap disturbance of themountain mixed forests of evergreen and deciduous broad-leaved speciesat MT. Dalaoling in the three Gorges I. The essential characteristicsof the gaps.Acta Phytoecol Sin25(3)276282 (in Chinese)
13. Szwagrzyk J Szewczyk J Bodziarczyk J 2001 Dynamics of seedling banks in beech forest:results of a 10-year study on germination, growth and survivalFor Ecol Manage141(3)237250. doi:10.1016/S0378‐1127(00)00332‐7
14. Tabarelli M Mantovani W 2000 Gap-phaseregeneration in a tropical mountain forest: the effects of gap structureand bamboo speciesPlant Ecol148(2)149155. doi:10.1023/A:1009823510688
15. Taylor A H Qin Z S 1988 Regenerationpatterns in old-growth Abies-Betula forests in the Wolong Natural Reserve, Sichuan ChinaJ Ecol76(4)12041218. doi:10.2307/2260643
16. Vogt K Gordon J Wargo J 2002 Ecosystem: the Science of Balance andManagement (in Chinese, trans. Ouyang H).BeijingScience Press (in Chinese)
17. Wang J X Xu J D 1995 Logging-clearingEcology, Forest Management and Regeneration Technology of Alpine ForestZone in the Upper Reach of the Yangtze RiverBeijingChina Forestry PublishingHouse (in Chinese)
18. Wang K Y 2004 Processes of Subalpine Forest Ecosystem in the West ofSichuanChengduSichuan Science and Technology Publishing House (in Chinese)
19. Wang Z P Li X G Shi S Y Qi D H He Z M Xu W W Deng X B 2001 Gap phasetree replacement in a conifer-broadleaved mixed forest in Jinyun mountain,ChongqingActa Phytoecol Sin25(4)399404 (in Chinese)
20. Watt A S 1947 Pattern and process in the communityJ Ecol35(1–2)122
21. Xian J R Hu T X Wang K Y Zhang Y B Zhu X M Xu J W 2004 Studies on the characteristics of gap border trees in thesubalpine coniferous forest in western SichuanFor Res17(5)3642 (in Chinese)
22. Xian J R Hu T X Zhang Y B 2004 Characteristics of gap in subalpine coniferousforest in western SichuanChin J Ecol23(3)612 (in Chinese)
23. Yang Y P 1990 Review on forest defense function in western Sichuan ProvinceIn: Li C BEcologicalStudy on Sichuan ForestChengduSichuan Publishing Houseof Science and Technology4954 (in Chinese)
24. Yang Y P Li C B Guan Z T 1992 Forests in SichuanBeijingChina Forestry PublishingHouse (in Chinese)
25. Zang R G Liu J Y Dong D F 1999 Gap Dynamics and Forest BiodiversityBeijingChinaForestry Publishing House
26. Zhang Y P Wang J X Ma Y X 2001 Characteristics analysis on differentthermal active surface in canopy gap of tropical secondary forestChin J App Ecol12(2)179184 (in Chinese)
27. Zhong Z C 1997 Ecosystem and environmental protectionIn: Zhong Z CAdvance in Plant EcologicalResearchChongqingPublishing House of Southwest China Teachers University653665 (in Chinese)