Ecology

ECOLOGY AND HUMAN OCCUPATION

Figure 1. New Guinea Topography. Source: New Guinea Flora 2011.

The island of New Guinea is a unique landscape, with a large number of habitats.  According to Diamond (1973), habitats range from “tropical forests to glaciers, within distances of less than 16km… Rugged topography and species isolation has promoted extreme speciation.”  One

Figure 2. Matschiei's Tree Kangaroo. Source: Matschiei's Tree Kangaroo 2011

estimate puts the number of distinct species in New Guinea to be 5-10% of the world total, while the Island is only .5% of the world’s total landmass (Fauna of New Guinea 2011).  Over 69% of mammal species are endemic, including the New Guinea Quoll, the Dwarf and Northern Cassowary and Matschie’s Tree Kangaroo (Fauna of New Guinea 2011; Matschie’s Tree Kangaroo 2011; Dwarf Cassowary 2011; Northern Cassowary 2011).  In addition, because there are few mountain regions in the tropics, New Guinea serves as a mountain bird species refuge (Diamond 1973).  This rugged montane terrain has prevented logging outside of the lowlands (Shearman 2009).

Figure 3. Dwarf Cassowary. Source: Dwarf Cassowary 2011.

Supporting Diamond’s view, Shermman (2009) writes that New Guinea contains one of the world’s largest remaining extant areas of tropical forest, with high levels of biodiversity and ecologically distinct areas.  For example, out of the 10 species of Tree Kangaroos, 8 are endemic to New Guinea.  Australia, on the other hand, has only two species, including the extremely rare Lumholtz Tree Kangaroo (Newell 1999).  Tree Kangaroos, according to Newell (1999) are “rare.. cryptic and nocturnal arboreal marsupials, susceptible to habitat change.  In Newell’s (1999) study, he found that after episodes of forest clearings, Tree Kangaroos tended to stay within their home ranges, living within debris, with elevated levels of mortality and morbidity.

In terms of human presence in New Guinea, agriculture in the Highlands has been practiced

Figure 4. Northern Cassowary. Source: Northern Casowary 2011.

for roughly 10,000 years, in the form of gardens or fields (Denham 2005).  Lowland agriculture tends to be arboriculture of tree crops, supplemented by small root crop gardens (Denham 2005).  Highland agriculture is nearly the opposite of the Lowland practice, as starch rich plants and vegetables are supplemented by limited arboriculture (Denham 2005).  Inter-montane valleys, between 1400 and 1800m are densely populated and highly agricultural (Fairbairn et al 2006).

Some of the ecosystems present in New Guinea are: alpine tundra, glacial, savanna, montane,

Figure 5. New Guinea Wolly Rat. Source: listsoplenty.com

lowland, rainforest, mangrove, wetlands, seagrasses and coral reefs (New Guinea Fauna 2011).  The Lowlands are highly malarial and contain some of the world’s largest, and least disrupted, mangrove forests (New Guinea Fauan 2011).