formation, human interactions, biology, and natural disasters By Kate Edwards, Tyler Huntley, Kerry Malm and Brian Murtaugh

Introduction What is Australasia Wide range of soil formation and orders Specific soil formations in New Zealand

Introduction Acidic soils in Australia Dipterocarp forests throughout the region Natural Disasters in Indonesia

The Formation of Raw Volcanic Soil in New Zealand

Tongariro Volcanic Center Located on New Zealand’s North Island. Raw volcanic soil dominates the landscape which is formed in tephra also know as volcanic ash.

Time and Parent Material Time: Raw volcanic soils are a very heterogeneous group of soils and are extremely young. Parent Material: Tephras of rhyolite, dacite and andesite

Climate and Topography Climate: Cold and high rainfalls. Topography: Raw volcanic soil forms in the vicinity of the source volcano

Biota Organisms: Most soil animals and micro- organisms are concentrated in the topsoil. Plant Life: Vegetation rapidly recovers on volcanic soils.

Profile Characteristics A horizon: is dark in color B horizon:10-15cm thick C horizon: is pale yellow-brown

Distinguishing features of Raw Volcanic Soils Naturally low levels of organic matter Generally coarse in texture Weakly weathered Highly susceptible to erosion Low bulk density Well drained, very high macroporosity

Acidic Soils of Australia Tyler Huntley

Acidic Sulfate Where: SE SW Australia Acid Subsoils  23 million hectares in Aus. 1/3 of Aussi covered Acid sulfate soils once made up the sea floor, Geologically pH levels

Agricultural Increase in acidification Soil nutrient uptake

Construction corrode metal pipes and dissolve concrete. foundations of buildings

Surface Water Run-off Consequences

Prevention Identifying them Liming Loss of crop production

Lowland Dipterocarp forests Soil associations

General Background Where: South East Asia Climate: very warm temperatures Growth: year round Use: timber industry, land degradation issues Stand characteristics: uneven aged, multi-layered Soils: strongly acidic, infertile, vulnerable to surface erosion

Types of Soils Ultisols – most common in SE Asia Inceptisols –Very steep slopes Oxisols Characterized by –Morphology –Physiochemical properties –Clay mineralogy

Soil Textures Primary factor for vertical distribution and storage of C, N, and P Coarse - clay content <35% –Thicker A and E horizons More roots and animals Larger volume of coarse pores Fine – clay content >50% –Mostly kaolinite

Soil Horizons Typically A, Ag, Eg, E, Bt or Btg, Bg & C No O layer –termites A Horizon –5 cm thick –Grayish with mottles edged with thin layers of iron oxide

Soil Horizons E Horizon –3-60 cm thick –Grayish and rust colored mottles –Clay coated in finer soils –Lower limit of major root penetration and animals B Horizon –Argillic (shallower in fine soils) C Horizon

Upper Horizons: Mechanical composition, bulk density and porosity Clay eluviation and illuviation in every soil –Usually in fines Bulk density increases with depth Higher % coarse pores at surface Higher % total pore space at surface Water holding capacity correlated with total porosity

Upper Horizons: Nutrient Cycling Highest storage of total C, N and P in the cm of soil –Increase with amount of clay Same with available N Sandy soils –Large amt of C, not N Exchangeable Mg and K correlated with clay AMOUNTS STILL VARY GREATLY, EVEN WITH SIMILAR CLIMATE AND VEG

Charismatic Mega Fauna Philippine Eagle Flying lemur Tarsier Philippine Cockatoo Flying foxes Bats Reptiles and amphibians

Landslides in Indonesia

Indonesia

Climate Tropical climate Dry season June-September Wet season December-March Moderate temperatures Large range of annual rainfall

Topography Indonesia has a wide range of topographic features

Vegetation Tropical plants Flowering plants Many trees

Soils Andosol (Andisols) –Very fertile –Used for horticulture and plantations Regosols (Inceptisols) –Quartz sand not suitable for dry-land farming Grumosols –High Ca & clay content –Used for crops in lowlands

Latosol –Tropical rainforests Lateritic –Tropical –High Al & Fe oxides Hydromorph (Oxisols) Alluvial Podsol –Highly leached –Coniferous forests

What is a landslide? Material moving down a slope due to gravity Many possible triggers Look like an avalanche 3 types –Slump –Flow –Lahar

Indonesia Mt. Semeru

Conclusion The soils of New Zealand’s Central North Island is mostly volcanic in origin Farmer’s crop yields are limited by the acidity of the sub soils in SE/SW Australia

Conclusion Subsoils are as important as topsoil in tropical Ultisols Tropical and volcanic soils in combination with precipitation leads to more frequently occurring landslides