Pedodiversity and Island Soil Geography: Testing the Driving Forces for Pedological Assemblages in Archipelagos of Different Origins

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1 Pedodiversity and Island Soil Geography: Testing the Driving Forces for Pedological Assemblages in Archipelagos of Different Origins William R. Effland, Ph.D. Soil Survey Division, USDA/NRCS A. Rodriguez-Rodriguez, Ph.D. Univ. de La Laguna, Tenerife, Canary Islands Juan J. Ibanez, Ph.D. Centro de Investigaciones sobre desertificacion, Spain 18 th World Congress of Soil Science Symposium 1.2A Spatial, Societal and Environmental Aspects of Pedodiversity July 10, 2006

2 Overview Biodiversity and Pedodiversity Research Objectives Island Study Areas Methods Results Hawaiian Islands Canary Islands

3 Introduction Island Biodiversity and Biological Communities Ecological Research Conservation Biology Limited studies of Pedodiversity and Soil Geography in Archipelagos

4 Quantification of Biological Diversity Definition of Diversity (Huston, 1994) Two primary components with statistical properties for any mixture of different objects The number of different types of objects in the sample Relative number or amount of each different type of object

5 Diversity and Human Judgement Definition of Diversity (cont d.) Two unavoidable value judgements Are the selected classes (and, by inference, class differentia) different enough to be considered separate types of objects? Are objects in a specific class similar enough to be considered the same type of object?

6 Role of Pedodiversity Analysis Conservation and preservation of the pedosphere as a natural resource Preservation of soils in their natural state increases opportunities to study ecological structure, function and dynamic properties Interactions with spatial pattern analysis

7 Research Objectives Analyze similarities and differences in the pedosphere for three archipelagos of different origins Study soil geographic distributions using taxonomic attributes Investigate landscape ecology methods for applications to pedologic research

8 Island Study Areas Hawaiian Islands Canary Islands Aegean Islands

9 Study Areas Hawaiian Islands Canary Islands Aegean Islands

10 Genetic Classification of Oceanic Islands (Nunn, 1994) Level One Plate-boundary islands Level Two Islands at divergent plate boundaries Islands at convergent plate boundaries Islands along traverse plate boundaries Intraplate islands Linear groups of islands Isolated islands Clustered groups of islands

11 Hawaiian Islands

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13 Aegean Islands

14 Methods Soil Databases Hawaiian Islands 6 main islands in southeastern region of island chain State Soil Geographic Database (STATSGO) 1:250,000 scale soils data Canary Islands 7 islands and 4 islets 1:250,000 scale unpublished (A. Rodriguez-Rodriguez) Aegean Islands CORINE database [Briggs and Martin, 1988] 682 islands with mostly calcareous and volcanic parent materials 1:1,000,000 scale EU soils map with FAO legend

15 Richness Indices Proportional abundance of an object Calculated with Excel software Shannon Diversity Index H = - p i.lnp i p i = n i /N where n i is the area of the i-th category and N is the total area Shannon and Weaver, 1949 Evenness E = H / H max = H / ln S E ranges from 0 to 1 S is richness or number of categories

16 Biogeographical Analyses Species-Area Relationship S = ca z S is the Number of species or taxa c is an empirical constant A is the Area z is a exponential value (theoretically near 0.25) McArthur and Wilson, 1967

17 Taxonomic Pedodiversity Richness Variety of species (e.g., soil types) Indices Number of different objects at a site Count of known soil types in a defined sampling unit Evenness or Equity Distribution of individuals among the species Object Abundance Models Distribution model that is closest fit to observed pattern of object abundance Examples log series, geometric series

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19 Hawaiian Islands

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22 Hawaiian Islands' Area and Maximum Elevation (Photo of HI landscape with taro fields, source: USDA/NRCS, 2005) 12,000 10,000 Area (km2) and Maximum Elevation (m) 8,000 6,000 4,000 2,000 0 Hawaii Maui Lanai Molokai Oahu Kauai Area_km Max_elev_m

23 Geomorphic Dynamics of the Hawaiian Islands

24 STATSGO Soil Order Area and Relative Island Age for the Hawaiian Islands (Excluding Miscellaneous Areas) Histosols Entisols Andisols Inceptisols Alfisols Aridisols Mollisols Ultisols Oxisols 3,500 3,000 Area Percent of Hawaii Island The Youngest and Largest Island Andisols 5% Entisols 5% Area Percent of Kauai The Oldest and Modal Size Island Ultisols 6% Entisols 26% 2,500 Inceptisols 51% Oxisols 28% Area (km 2 ) 2,000 1,500 Histosols 35% Mollisols 10% Inceptisols 26% 1, Hawaii Maui Lanai Molokai Oahu Kauai

25 Hawaii Island Climate and Precipitation Water Balance Source: USGS,

26 Soil Order Area Distributions (km 2 ) Among the Hawaiian Islands Hawaii Maui Lanai Molokai Oahu Kauai 100% 90% 80% 70% Relative Percentage 60% 50% 40% 30% 20% 10% 0% Alfisols Andisols Aridisols Entisols Histosols Inceptisols Mollisols Oxisols Spodosols Ultisols Vertisols Kauai Oahu Molokai Lanai Maui Hawaii

27 Canary Islands Fits of diferent variables to power laws in Canay Islands c z r dst c z r dst Area-Relief Relief-Area *** *** *** *** Area-FAO Soil* Relief-FAO Soil* Area-USDA Soil Relief USDA-Soil Area-Bioclimate Relief-Bioclimate < Area-Wild Veg Relief-Wild Veg. < Area-Geology Relief-Geology Area-Quatern. < Relief Quaternary Area-Nº Plants * < Relief-Nº Plants* < Area-Coleopt.* Relief-Nº Coleópt* < Area-Habitats Relief-Habitats <

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29 Canary Islands

30 Canary Islands Diversity Analysis

31 Canary Islands Mean Annual Precipitation

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33 Pedodiversity Analysis Conservation and preservation of the pedosphere as a natural resource Preservation of soils in their natural state Increased opportunities to study ecological structure, function and dynamic properties Interactions with spatial pattern analysis

34 Thank You! Questions?