The mountains that run the length of the peninsula are the eastern extension of the mountainous spine that runs the length of New Guinea. The Watut-Tauri Gap separates the southeastern ranges, including the Owen Stanley Range, from the mountains of Central New Guinea.[5]Mount Victoria (4,038 m) in the Owen Stanley Range is the ecoregion's highest peak.[6]
The collision of the Owen Stanley Range is made up mostly of continentally-derived metamorphic rocks overlain by basaltic volcanic rocks.[7] The Bowutu Mountains and eastern Kuper Range consist of ultramafic rocks derived from oceanic crust and upper mantle. This formation is known as the Bowutu Ultramafic Belt or Papuan Ultramafic Belt.[5]
The climate of the ecoregion varies with elevation. The lowlands are humid and tropical. Average temperatures decrease with elevation, and the highest portions of the Owen Stanley Range experience regular freezing temperatures.[8]
The ecoregion's natural vegetation is humid evergreen rain forests. The forest types include alluvial rain forest on lowland plains, hill forests at the foot of the mountains, montane forests above 1000 meters, upper montane forests, and high mountain forests below the tree line. The highest peaks of the Owen Stanley Range are home to sub-alpine grasslands and shrublands, which are included in the separate Central Range sub-alpine grasslands ecoregion.[9]
^Eric Dinerstein, David Olson, et al. (2017). An Ecoregion-Based Approach to Protecting Half the Terrestrial Realm, BioScience, Volume 67, Issue 6, June 2017, Pages 534–545; Supplemental material 2 table S1b. [1]
^ abcShearman, P. and Bryan, J. (2011), A bioregional analysis of the distribution of rainforest cover, deforestation and degradation in Papua New Guinea. Austral Ecology, 36: 9-24. https://doi.org/10.1111/j.1442-9993.2010.02111.x
^Wikramanayake, Eric; Eric Dinerstein; Colby J. Loucks; et al. (2002). Terrestrial Ecoregions of the Indo-Pacific: a Conservation Assessment. Washington, DC: Island Press.
^Smith, I. E. M. (2013), The chemical characterization and tectonic significance of ophiolite terrains in southeastern Papua New Guinea, Tectonics, 32, 159–170 doi:10.1002/tect.20023.
^Wikramanayake, Eric; Eric Dinerstein; Colby J. Loucks; et al. (2002). Terrestrial Ecoregions of the Indo-Pacific: a Conservation Assessment. Washington, DC: Island Press.
^Eric Dinerstein, David Olson, et al. (2017). An Ecoregion-Based Approach to Protecting Half the Terrestrial Realm, BioScience, Volume 67, Issue 6, June 2017, Pages 534–545; Supplemental material 2 table S1b. [2]
