Introduction to Soils and Ecological Sites Presented by
Introduction to Soils and Ecological Sites Presented by: Sarah Lamagna Ecologist, NOC
Why gather soils info? We’re monitoring change over time 1953 1956 2010 Soils help us understand landscape change Soils help differentiate ecological sites
Ecological Sites A kind of land, defined by its soils, topography and climate that: 1) potentially produces similar kinds and amounts of vegetation 2) responds to disturbances and drivers similarly (e. g. , grazing and rainfall)
So what are the steps in identifying ecological sites?
1. Gather information in office • Key to Ecological Sites • Topographical Map • Soil Map Unit Descriptions • Ecological Site Descriptions (ESD’s) • Climate information
Web Soil Survey
Ecological Site Descriptions • Based on soil map units • Each soil map unit matches up with one or more ecological sites
2. Go to the field • Navigate to your site. • Find out where you are on the maps. • According to the soil map units in the area, what ecological site(s) could you be on?
3. Compare physical characteristics – DIG A PIT! • Do you have the same topography as the ESD? • Are you at the same elevation as the ESD? • Are the soil properties (esp. texture) the same as described in the soil map unit component and associated ESD?
4. Compare vegetation • What plants are on the site? • Which state or community are you in?
What exactly goes in to digging a soil pit?
A soil scientist helps!!!
What soil properties does AIM require you to measure? Texture Coarse Fragments Color Percent Clay Effervescence Structure Bulk Density Soil Horizon Depth
Soil Profile Data Sheet Part of Plot Characterization Data Sheet
Match each soil property with its corresponding reason for collecting it Texture Indicator of calcium carbonate content Structure Describes entire soil ped to help determine ecological site ID Coarse Fragments Indicator of the amount of organic matter which is important for water holding capacity and nutrient availability Percent Clay Affects soil water availability through depth that water can penetrate and residence time that water is available to plants Effervescence Affects all soil processes and one of the most important soil properties Color Affects soil water availability through infiltration, storage, and evaporation Horizon Depth Important in understanding the processes of water infiltration and availability, soil stability/erodibility, and plant rooting
How many horizons do you see? What are the differences in soil properties between horizons?
How many horizons do you see in each soil pit? Sandy Site Loamy Site
How many horizons do you see in each soil pit? Sandy Site Loamy Site
What differences in soil properties can you see? Sandy Site Loamy Site
What differences in soil properties can you see? Sandy Site Loamy Site Sandy Clay Loamy Sandy Loam Fine Sandy Loam Calcic Petro-calcic Sandy Clay Loam Calcic w/ ~20% Ca. CO 3
How many horizons do you see in each soil pit?
How many horizons do you see in each soil pit?
What differences in soil properties can you see?
What differences in soil properties can you see? Sandy Loamy Sand Silty Clay Loam Silt Loamy Sand Calcic w/ ~20% Ca. CO 3 Loamy Sand
Soil profiles common to Oregon A horizon High OM Clayey Welded tuff Compaction VERY Common
Soil profiles common to Oregon Ash VERY Common Vertic Clay Weaker Structure Welded Tuff
Soil profiles common to Oregon Ash Vertic Clay – High Rock Fragment % Welded Tuff VERY Common
Soil profiles common to Oregon Ash Vertic Clay – Color change
Soil Texture Flowchart
Soil and ecological site resources • • • Web Soil Survey Soil. Web App for i. Phone and Android Soil Series Descriptions List of Published Soil Surveys Approved Ecological Site Descriptions Land. PKS App for Site Characterization
For more soil background info: Field Book for Describing and Sampling Soils – plus video on how to use it Factors of Soil Formation – classic book by Hans Jenny available online The Nature and Properties of Soils – book to purchase that provides a clearly written, general overview Soils: Genesis and Geomorphology – textbook to purchase
Questions? Getting your hands dirty will help!
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