Habitat Evaluation Notes

Habitat Evaluation

Introduction

  • Habitat Definition: The habitat of an organism is its home, fulfilling requirements for survival and successful existence.

  • Habitat Components:

    • Living (biotic) components: plants and animals.

    • Physical (abiotic) components: climate, rocks, crevices, soil, and water.

    • These components provide animals with food, shelter, and water.

  • Vegetation Importance: Vegetation is a major contributor to habitat quality, especially when assessing environments for mineral wealth, health status, and physical conditions.

  • Plant Community: An assemblage of plant species with a relatively uniform appearance in a consistent physical environment.

    • Each plant community has unique properties and reacts differently to management practices, fire, and grazing.

  • Animal Preferences: Animals prefer palatable plant species and those that provide cover and shelter based on plant density.

  • Objectives:

    • Ecotourism: Requires high diversity of animal and plant species, as each has a specific niche.

    • High diversity of fauna and flora needs high diversity of habitats and plant communities.

    • Functional system: Can be manipulated (e.g., create grasslands and bushveld, add resting and nesting places, waterholes) to increase habitat diversity.

  • Planning Ahead: Essential for habitat management.

Habitat Classification

  • Purpose: To establish a system improving management and communication.

  • Contributions: Classification, description, and mapping can

    • Identify homogenous habitat types.

    • Gather information of veld conditions, plant biomass production, ecological grazing, and browsing capacity.

    • Determine habitat suitability for specific animal types.

    • Recognize deficiencies and disturbances, indicating need for control and conservation (e.g., bush encroachment, soil erosion, veld reclamation, habitat optimization).

    • Design and development of recreation and ecotourism activities (e.g., hiking, camping, mountain biking).

    • Identify ecologically sensitive areas (e.g., erodible soils, water catchments, wetlands, floodplains).

    • Gather information on distribution of endangered/rare plants/animals, poisonous/problem plants, key plants indicating overgrazing, exotic and invasive plant species.

    • Plan layout and develop burning and monitoring programs.

Remote Sensing and Aerial Photographs

  • First Step: Habitat evaluation starts with habitat and vegetation maps to develop a wildlife management plan.

  • Remote Sensing Applications:

    • Google Earth Pro

    • Light Detection and Ranging (LIDAR) satellite images

    • Black and white aerial photographs

    • Compact Spectrographic Imager (CASI)

    • Airborne Laser Terrain mapper (ALTM)

    • Remote Airborne Mapping System (RAMSTM)

Map Considerations

  • Direction: North should always be oriented upwards.

  • Scale: Commonly 1:50,000 to 1:10,000.

    • Example: 1:50,000 means 1 cm on the map equals 50,000 cm (0.5 km) in reality.

  • Stereoscope: Use to achieve a 3D view.

  • Shadows: Be cautious of shadows as they might obscure features.

Map Development Sequence

  • Draw:

    • Ranch boundary.

    • Main terrain morphological units.

      • Further delineated into:

        • Crests

        • Slopes

        • Plateau

        • Cliffs

        • Ravines

        • Foothills

        • Plains

        • Valleys

        • Mountainous areas, plains, drainage lines.

    • Homogenous vegetation units such as grasslands and bushveld.

    • Distinct shapes = usually man-made

Map Refinement

  • Color Analysis: Color variations can indicate soil differences or canopy cover but might also be photographic errors.

  • Map Age: Maps can be outdated (up to 20 years old), leading to inaccuracies.

  • Final Product: Habitat units, also known as "MANAGEMENT UNITS."

  • Confirmation: Verify map accuracy and refine borders.

  • Surveys: Conduct relevant surveys after map satisfaction.

Remote Sensing Technologies

  • LIDAR (Light Detection and Ranging satellite images): Uses laser pulses from aircraft or drones to measure ground elevation and create detailed 3D terrain models.

  • Aerial Photographs: Captures high-resolution, multi-band images from above to analyze vegetation, water, and land features.

  • CASI (Compact Spectrographic Imager): Emits laser beams from an aircraft to map the shape and features of the Earth’s surface with high precision.

  • ALTM (Airbone Laser Terrain mapper): Emits laser pulses from an aircraft to accurately map the Earth's surface and elevation in 3D.

  • RAMSTM (Remote Airborne Mapping System): A GIS-based system used to assess, monitor, and manage natural resources by integrating spatial and environmental data.

  • AGIS: Integrates aerial data and GIS technology to manage and analyze spatial information for environmental and land use planning.

Habitat & Vegetation Analysis

  • Includes seven aspects:

    • Terrain morphology

    • Geology and soil

    • Drainage

    • Vegetation

    • Plant phenology

    • Human disturbances

    • Suitable techniques

Terrain Morphology

  • Landscapes divided into terrain morphological units that differ in:

    • Exposure to climatic factors

    • Rockiness

    • Slope

    • Aspects

    • Soil type and depth

    • Nutrients status

    • Soil water content

    • These influence plant growing conditions and shelter for animals.

  • Slope Orientation:

    • North-facing slopes in South Africa are warmer and drier than south-facing slopes.

    • Floristic composition differs between slopes.

    • Vegetation on north and west-facing slopes is generally more palatable.

  • Slope Characteristics:

    • Slopes are prone to soil erosion.

    • Slopes typically have shallower, rockier soils, resulting in sparser vegetation cover.

  • Vegetation Heterogeneity:

    • Greater variation in terrain increases vegetation heterogeneity, supporting a greater variety of game species.

Geology and Soil

  • Geological Formations: In semi-arid South Africa, they correlate with soil types and plant communities.

  • Soil Types:

    • Soils from shale, mudstone, dolomite, and igneous rocks (dolerite, diabase, basalt, and andesite) are clayey and nutrient-rich, supporting palatable grazing in fertile savannas or sweet veld regions.

    • Soils from wind-blown sands and sedimentary rocks (sandstone, quartzite, conglomerates) are sandy, well-drained, and leached, found in infertile savannas or sour veld regions with low nutrient content and less palatable grazing.

  • Soil Texture: Refers to the ratio of sand, silt, and clay particles.

Soil Properties

  • Influence of Soil Texture:

    • Water and nutrient retention

    • Water infiltration rate

    • Root penetration

    • Nutrient leaching

    • Aeration

    • Soil temperature and structure

  • Soil Structure:

    • Primary soil particles form structural units called peds, defining soil structure (e.g., blocky, spheroidal, platy, prismlike).

  • Clayey Soils:

    • Well-developed structure improves aeration, water passage, and root growth.

    • Excessive structure can hinder root penetration and plant growth.

  • Topsoil Color:

    • Darker topsoil indicates higher carbon content and greater productivity.

    • Mapping soil color in the top 250 mm can assess habitat quality.

  • Munsell Soil Colour Charts:

    • Used to measure soil carbon content.

Drainage

  • Importance: Catchment areas of streams and rivers (including sponges & vleis) are essential for riparian ecosystems and water supply.

  • Prohibited Actions:

    • Draining

    • Overgrazing

    • Frequent burning

  • Consequences: These actions can cause trampling, soil erosion, and a decline in habitat abundance, quality, and water resources.

Vegetation

  • Definition: Vegetation type, plant community, or habitat on a wildlife ranch is an area with homogeneous climate, landscape, soil, and plant composition, resulting in consistent grazing and browsing value and biomass production potential.

  • Management:

    • Assign names and define plant communities.

    • Calculate potential productivity, numbers, and ratios of browsers and grazers for each management unit.

Plant Phenology

  • Definition: Different growth phases in the lifecycle of a plant (foliar/vegetative, flowering, and fruiting phases).

  • Impact:

    • Availability and palatability change over these phases/seasons.

  • Influence On Animals:
    *Influences animal movement, habitat choice, feeding preferences, and production traits (condition, herd size, reproduction).

Human Disturbances

  • Types of Disturbances:

    • Cultivation

    • Roads

    • Dams

    • Pens or animal capture areas

    • Any other physical development

  • Management:

    • All disturbed areas must be clearly defined.

  • Habitat Quality: Some areas act as important habitats for certain species but are usually uninhabitable due to severe degradation.

  • Recovery: Disturbed areas require a minimum 10-year recovery plan.

Suitable Techniques

  • Expertise Required: Veld classification and conditions assessment require considerable professional expertise and data analysis capability.

  • Recommendation: This is best left to a qualified plant ecologist.