Trees For Rehabilitation (Landcare Reafforestation)

This course is designed for people working or wishing to work with environmental rehabilitation and contaminated sites recovery. Learn the best techniques for plant selection and establishment, seed collection, storage and germination and post-establishment management and control.

Student Comment: 'I definitely learned a lot from [the course) but it was also beneficial in affirming [and raising my confidence] in what I already knew.'  Katrina Merrifield, Masters Conservation Science, NZ, studying Trees for Rehabilitation course

Lesson Structure

There are 10 lessons in this course:

1. APPROACHES TO LAND REHABILITATION
   • The importance of trees - Erosion control
   • Understanding plants
   • Understanding plant identification
   • Land management programs
   • Biodiversity
   • Soil degradation
   • Erosion - Water erosion, Wind erosion, Control of erosion
   • Salinity - Sources of salt, Control methods for salinity
   • Soil acidification and other problems - Soil acidification, Compaction, Chemical residues
   • Rehabilitation
2. ECOLOGY OF SOILS AND PLANT HEALTH
   • Biomass
   • The Ecosystem - Abiotic components, Biotic components, Ecological concepts, The web of life, Other relationships between plants and animals
   • Indigenous species
   • Creating habitat corridors for wildlife – benefits, Other benefits, Situating corridors, Types of corridors
   • Design considerations
   • Edge effects
   • What can happen at edges
   • In general
   • Soils - How soils develop naturally, The soil environment, Soil composition, Soil temperature
   • Mycorrhizae
   • Soil physical characteristics - Soil profile, Soil texture, Soil structure
   • Soil chemical characteristics - Soil pH, Cation exchange capacity, Buffering capacity
   • Improving soils
   • Plant nutrition - What nutrients do plants need
   • The nutrient elements - The macronutrients, The micronutrients
   • Choosing the right fertilizer - How much fertilizer to apply
   • Diagnosis of nutritional problems
   • Pests and diseases and plant growth - Environmental factors
   • Resistant plant species and cultivars
   • Pests and Diseases - Biological control, Diseases include, Pests include, Life cycles, Preventative control
3. INTRODUCTION TO SEED PROPAGATION TECHNIQUES
   • Seed propagation - Seed sources – 4 sources, Maintaining genetic identity in seed, Hybrid seed production
   • Why do plants produce so much seed
   • Collecting and harvesting seed – guidelines
   • Selecting plants to collect from
   • Timing
   • Methods of collection
   • Cleaning seed
   • Storing seed
   • Difficult seeds - Germination treatments, Soaking in boiling water
   • Stratification
   • Fire
   • Leaching seeds
   • Sowing your seeds - When to sow, Propagation media
   • Containers for propagation
   • The bog method
   • Pricking out or tubing seedlings - After care
   • Quality control – The UC System of Soil Mixes
   • Example of a production system
   • Propagation stage
   • Transplanting stage
   • Growing on stage
   • Distribution stage
   • Sources of seed and information
   • Books on seeds and seed germination
4. PROPAGATION AND NURSERY STOCK
   • Asexual propagation - Why cuttings? How to propagate a cutting, Classification of cutting types, Maintaining genetic identity in seed
   • Types of Cuttings - Softwood cuttings, Semi-Hardwood Cuttings, Hardwood cuttings, Variations on cuttings, Nodal cuttings, Basal cuttings, Root cuttings
   • Stock Plants - Planting out stock plants, Treatment throughout the year, Stock plants for root cuttings
   • Ways of getting roots on difficult to root cuttings - Hormone treatments, Etoliation and banding, Cutting grafts, Misting/fogging, Light treatments, Bacterial treatments, Combining treatments
   • Hormone Treatments in detail
   • Nursery hygiene
   • Spread of pests and diseases
   • Recommended nursery hygiene practices
   • Propagating Mixes - Vermiculite, Perlite, Sand, Rockwool, Peat moss
   • Potting Media - Potting Soil Mixes, Pine Bark, Containers for potting up plants
   • How to maintain plants in pots - Feeding, Watering, Ventilation and light, Temperature, Growing-on areas for container plants, Stop roots growing into the soil, Hardening off rooted cuttings
   • The greenhouse - Types of greenhouses, Heated or unheated, Deciding on what you need, Problems with greenhouses, Environmental controls in the greenhouse, Temperature control
   • Greenhouse irrigation methods, Runoff and leachate, Irrigation systems, Other structures for growing plants, The nursery site, How to propagate different species
5. DEALING WITH CHEMICAL PROBLEMS
   • Soil contamination
   • Symptoms on plants of chemical contamination
   • Foliage burn
   • Treating foliage burn
   • Rehabilitating damaged soils
   • Prevention
   • Accidental spillage
   • Rehabilitation methods
   • Using plants to extract contaminants
   • Growing plants on contaminated soil
   • Rehabilitating a building site
   • Soil chemical composition and plant growth
   • Alkaline soils
   • Lime contaminated soils
   • Trees which grow in lime soils
6. PHYSICAL PLANT EFFECTS ON DEGRADED SITES
   • Pioneer plants
   • Site protection - Windbreaks/shelterbelts, Windbreak design, Other considerations
   • Designing and planting a firebreak - Fire prone areas, How to arrange plants, Distances from buildings, Consider prevailing winds, Consider vehicular access, Maintenance, Fire resistant plants, Plants likely to burn
   • Storm water, waterlogging and drainage - Storm water
   • Drainage - Water-logging on a home-site, Constructing a swamp
   • Soil Compaction
7. PLANT ESTABLISHMENT PROGRAMS
   • What to plant where
   • Climate - Temperature, Wind, Frosts, Extreme hazards, Microclimates
   • Plant selection criteria, Economics, Ongoing costs, Longevity, General hardiness
   • Planting - When to plant
   • Plant protection methods - Supporting trees, Staking, Frost protection for young trees, Sun protection, Mulching, Fencing, Wind protection
8. HOSTILE ENVIRONMENTS
   • Planning
   • Rehabilitation techniques
   • Coping with dry conditions - Overcoming dry soils
   • Mulch - How to lay mulch, Mulch materials, Commonly used organic mulches, Living mulch and cover crops
   • Weed management - Types of weeds, How are weeds spread? Preventative measures, Weed control, Methods, Commonly used herbicides
   • Trees and large shrubs that tolerate salt
   • Plant species that tolerate salt
9. PLANT ESTABLISHMENT CARE
   • Planting procedures - Evergreens, Deciduous and bare-rooted plants
   • Water and plant growth
   • Transpiration
   • Maintaining appropriate water levels
   • Symptoms of water deficiency
   • Symptoms of excess water
   • Period of watering
   • Minimizing plant water requirements
   • Plant health – Conducting an inspection
   • The Plant - Examining leaves, Examining fruit and flowers, Examining stem and branches, Examining roots, Identifying damage
   • The Immediate Environment - Examining the soil, Examining surrounding plants, Other environmental factors, Methods of inspection
   • Prioritizing problems
   • Research
10. REHABILITATING DEGRADED SITES
    • Environmental Assessment - Conducting an Environmental Audit
    • Implementing a Land Rehabilitation Management Program - determining land objectives, determining a program and replanting.

Each lesson culminates in an assignment which is submitted to the school, marked by the school's tutors and returned to you with any relevant suggestions, comments, and if necessary, extra reading.

Aims

• Develop the ability to write the scientific names of plants and to identify and compare different types of land degradation and rehabilitation alternatives.
• Outline the basics of ecology concepts and how soils, flora and fauna interact and affect one another.
• Develop basic seed propagation skills and knowledge.
• Describe further propagation and nursery techniques.
• Describe the effect of plants on improving chemical characteristics of a degraded site.
• Determine the physical effect plants have on improving a degraded site.
• Determine appropriate plant establishment programs.
• Determine procedures to care for plants, during establishment in a hostile environment.
• Determine techniques to maximise plant development in land rehabilitation situations.
• Determine the management procedures and rehabilitation requirements of degraded soil.

What You Will Do

• Determine ten different examples of land degradation on different sites.
• Explain different reasons for land requiring rehabilitation, including:
  • Salination
  • Erosion
  • Mining
  • Grazing
  • Vegetation harvesting
  • Pests
  • Reduction of biodiversity
  • Soil contamination
  • Urbanisation.
• Compare the effectiveness of different policy approaches to land rehabilitation by different agencies and organisation, including:
  • Different levels of government
  • Mining companies
  • Developers
  • Conservation groups (i.e. tree planting bodies, land care groups).
• Develop a risk analysis for a specified site to be rehabilitated, by determining a variety of plant health problems which may impact on the success of plant establishment.
• Analyse the failure of plants to grow successfully on a visited land rehabilitation site.
• Develop a procedure to enhance the success rate of land rehabilitation plantings on a degraded site visited by you.
• Describe the use of mulches, to maximise plant condition in a specified land rehabilitation tree planting project.
• Explain different processes of establishing seedlings on land rehabilitation in:
  • tubestock nursery production
  • direct seeding
  • pre-germinated bare rooted seedlings.
• Determine factors which affect the viability of establishing five different species of plant seedlings, from five different plant families; on a specific degraded site.
• Compare the benefits of acquiring plants for a project by buying tube stock, with propagating and growing on, or close to, the planting site, with reference to:
  • costs
  • plant quality
  • local suitability
  • management.
• Prepare production schedules for a plant species, using different propagation techniques, summarising all important tasks from collection of seed to planting out of the tubestock.
• Calculate the cost of production for a tube stock plant, according to the production schedule developed by you.
• Estimate the differences in per plant establishment costs, for tube stock, compared with direct seeding methods, for planting on a degraded site.
• Describe three different methods of planting trees for rehabilitation purposes.
• Describe different plant establishment techniques, including:
  • wind protection
  • frost protection
  • pest control
  • water management
  • weed management.
• Describe an appropriate method for preparing soil for planting, at a proposed land rehabilitation site in your locality.
• Evaluate plant establishment techniques used by two different land rehabilitation programs inspected by you at least twelve months after planting was carried out.
• Determine the needs of plants after planting, on two different proposed land rehabilitation sites.
• Describe two different, efficient ways, of catering to the needs of large numbers of plants after planting.
• Collect pressed specimens or photographs of twenty trees for a herbarium of suitable trees for rehabilitation, and including information on the culture and care of each tree.
• Describe different types of soil degradation, detected in your locality.
• Determine the risk factors involved in soil degradation, relevant to your locality.
• Compare two different alternative methods of treating each of three different soil degradation problems identified and inspected by you.
• Develop an assessment form to use for evaluating the sensitivity of a site to land degradation.
• Evaluate a site showing signs of degradation, selected by you, using the assessment form you developed.
• Compare different approaches to land rehabilitation, to determine strengths and weaknesses of alternative options on a site to be rehabilitated.
• Determine techniques to maximise plant development in land rehabilitation situations.
• Explain the different ways of producing seedling trees for land rehabilitation purposes.
• Determine appropriate plant establishment programs.
• Develop procedures to care for plants, during establishment in an hostile environment.
• Manage the rehabilitation of degraded soil.
• Explain the effect of plants on improving a degraded site, both physically and chemically.
• Plan a rehabilitation program for the degraded site you evaluated, including
  • a two year schedule of work to be completed;
  • list of quantity and type of materials required;
  • approximate cost estimates.
• Explain the effect six different plant species may have resisting soil degradation.
• Explain how different plants can have different impacts upon the chemistry of their environment, including both air and soil.
• Evaluate the significance of a group of plants, to the nature of the microclimate in which you find them growing.
• Compare the appropriateness of twenty different plant species for different degraded sites.
• Determine five plant varieties, suited to each of six different degradation situations.

Rehabilitation Techniques

Remember that forests are representative of more mature ecosystems; they do not develop overnight, but over successive generations of favourable conditions.

It might be necessary to artificially create these favourable conditions before the proposed tree planting takes place. Weed species may need to be controlled, as well as feral or native species. Introduced pigs, rabbits, goats and hares can decimate tree plantings, but so too, can native animals and livestock. Tree guards can be employed until the trees are of sufficient size to withstand foraging animals. However, it should be noted that during drought conditions, when food is scarce, the ability of an animal to reach the succulent, tender foliage of saplings should not be underestimated. To do so, will prove a waste of your time and money!

Rehabilitation of the land may require that certain primary species such as ground covers, annuals, perennials and shrubs be established before planting tree species or it needs to be done in conjunction with planting them. This approach is necessary with gully erosion problems and foreshore rehabilitation. The smaller, faster growing species act to hold the soil together in much quicker time than a tree takes to develop, although trees tend to do the same job on a larger scale once they are established. It may also mean that certain measures need to be used until groundcovers or under-storey plants become established. Pioneer plants as discussed in earlier lessons may also be helpful.

There are also many reasons why plants do not grow well in a particular place. Most of these are caused by a combination of local climate and soil conditions. Some common problems include:

• undefined Alkaline soils – these are soils with a pH greater than 7
• undefined Waterlogged soils – where drainage is poor, generally due to the site being in a low lying area, or because of poorly structured soils, such as heavy clays
• undefined undefined Salinity – in some parts of the world, this is a problem not just in agricultural areas, but increasingly in urban fringe areas
• undefined Strong winds, poor soils and salty conditions associated with coastal areas
• Windy areas
• undefined undefined Hot, dry areas.