疏林草原

稀树草原
(重定向自稀树草原

疏林草原(英文: savannasavannah),又译稀树草原(Taíno阿拉瓦克语:sabana),是一种疏林与草原交错分布的生物群系,较森林草原更为干旱。疏林草原分为热带或亚热带的疏林莽原(常见)、温带的沙地疏林草原(较罕见)以及安第斯高山疏林草原乃至喜马拉雅的(干)热性灌草丛(极罕见)。

坦桑尼亚恩戈罗恩戈罗保护区的疏林莽原。

热带莽原主要分布于非洲巴西澳大利亚的部分地区。是一种混合林地与草地的生态系统,其特征是树木的间距大,树冠层不至密闭,因此有足够的光线到达地面,可以供应完整草本植物层。[1][2][3]

澳大利亚北部的典型热带疏林莽原,可见树木的高密度与规则分布等特征。

尽管树木密度很高,疏林莽原的树冠层仍是开放的。[4]就字面上看来,或许会以为树木分布广泛,分散,但在许多热带稀树草原,与森林相比,树木密度更高,但树木的间距比较规则。[5][6][7][8]南美稀树草原( cerrado sensu stricto 和 cerrado dense)的树木密度为每公顷 800-3300 棵树(树/公顷),此密度与南美热带森林相仿或甚或更高(800- 2000 棵树/公顷)。[5][7][8] 几内亚稀树草原的树木密度为 129 棵树/公顷,而河岸森林为 103 棵树/公顷。[6] 澳大利亚东部稀树草原的树木密度,与同地区硬叶林的平均树木密度相当(约为100 棵树/公顷)。[9]

疏林莽原的另一个特点是水源供应的季节性:大部分降雨仅限于一个季节,经常位于森林与沙漠或草原之间的过渡地带。不同类型的生物能适应高温而有长干季的环境:植物均有耐旱特性,食物资源丰富,草食性动物繁盛,有垂直分层觅食特性。长颈鹿大象食用较高层树叶黑犀牛大羚羊食用较低矮树和灌木,小羚羊吃最低层的树叶,斑马吃草类顶部,而瞪羚则啃食嫩草及草根。疏林莽原约占地球陆地面积的 20%。[10]

分类及生态区 编辑

  • 热带及亚热带稀树莽原
  • 温带稀树莽原
  • 地中海式稀树莽原
  • Flooded savannas
  • Montane savannas (高地稀树莽原)

参考 编辑

  1. ^ Anderson, Roger A., Fralish, James S. and Baskin, Jerry M. editors.1999. Savannas, Barrens, and Rock Outcrop Plant Communities of North America. Cambridge University Press.
  2. ^ McPherson, G. R. (1997). Ecology and management of North American Savannas. Tucson, AZ: University of Arizona Press.
  3. ^ Werner, Patricia A.; B. H. Walker; P. A Stott. Introduction. Patricia A. Werner (编). Savanna Ecology and Management: Australian Perspectives and Intercontinental Comparisons. Oxford: Blackwell Publishing. 1991 [2021-12-30]. ISBN 978-0-632-03199-3. (原始内容存档于2021-12-30). 
  4. ^ Alexandro Solórzano, Jeanine Maria Felfili 2008”Comparative analysis of the international terminaoolgy for cerrado” IX Symposio Nacional Cerrado 13 a 17 de outubro de 2008 Parlamundi Barsilia, DF
  5. ^ 5.0 5.1 Manoel Cláudio da Silva Jánior, Christopher William Fagg, Maria Cristina Felfili, Paulo Ernane Nogueira, Alba Valéria Rezende, and Jeanine Maria Felfili 2006 “Chapter 4. Phytogeography of Cerrado Sensu Stricto and Land System Zoning in Central Brazil” in “Neotropical Savannas and Seasonally Dry Forests: Plant Diversity, Biogeography, and Conservation” R. Toby Pennington, James A. Ratter (eds) 2006 CRC Press
  6. ^ 6.0 6.1 Abdullahi Jibrin 2013 “A Study of Variation in Physiognomic Characteristics of Guinea Savanna Vegetation” Environment and Natural Resources Research 3:2
  7. ^ 7.0 7.1 Erika L. Geiger, Sybil G. Gotsch, Gabriel Damasco, M. Haridasan, Augusto C. Franco & William A. Hoffmann 2011 “Distinct roles of savanna and forest tree species in regeneration under fire suppression in a Brazilian savanna” Journal of Vegetation Science 22
  8. ^ 8.0 8.1 Scholz, Fabian G.; Bucci, Sandra J.; Goldstein, Guillermo; Meinzer, Frederick C.; Franco, Augusto C.; Salazar, Ana. 2008 “Plant- and stand-level variation in biophysical and physiological traits along tree density gradients in the Cerrado”, Brazilian Journal of Plant Physiology
  9. ^ Tait, L 2010, Structure and dynamics of grazed woodlands in North-eastern Australia, Master of Applied Science Thesis, Central Queensland University, Faculty of Science, Engineering and Health, Rockhampton.
  10. ^ Sankaran, Mahesh; Hanan, Niall P.; Scholes, Robert J.; Ratnam, Jayashree; Augustine, David J.; Cade, Brian S.; Gignoux, Jacques; Higgins, Steven I.; Le Roux, Xavier. Determinants of woody cover in African savannas. Nature. December 2005, 438 (7069): 846–849. Bibcode:2005Natur.438..846S. ISSN 0028-0836. PMID 16341012. S2CID 4344778. doi:10.1038/nature04070 (英语). 

参见 编辑