Trees For Rehabilitation (Reafforestation)

OPEN LEARNING COURSE -TREES FOR REHABILITATION

Would you like to work in a field that helps the environment?  Environmental rehabilitation of degraded landscapes and contaminated sites is an important and growing field - this course covers the fundamentals required to start or advance your career.

The significance of caring for the environment has been receiving more and more attention in recent times as we come to understand the importance of limited resources and the effects of human activities on the environment. The desertification, erosion and general degradation of once fertile lands is prompting us to investigate why and how these processes have occurred. It has also lead to research into how we can reverse and stop further damage to our environment.

Natural forests are amongst the most stable and productive ecosystems. We need to plant and conserve forests for their conservation value, to help maintain healthy air, soil and water and for their potential to provide food, forage, fuel, timber and even medicines.

This course is designed for people working or wanting to work with environmental rehabilitation and contaminated sites recovery. It develops an understanding of environmental systems and the rehabilitation of degraded landscapes. You will learn about seed collection, storage and germination, propagation, plant selection, establishment techniques, and controlling pest and disease after planting.

Horticulture Tutors

Diana Cole B.A. (Hons), Higher Dip. (Garden Design), RHS Advanced Cert. Horticulture, Cert Admin.Mgt., Dip. Inst. Personnel Management

In addition to her RHS horticulture, garden design, City & Guild construction, NPTC pesticide/legislation and business/management qualifications, Diana has a variety of skills drawn from setting up Arbella Gardens, a landscape gardening business. She also has administrative, management and training delivery experience drawn from her employment in other organisations such as the NHS and other educational institutions such as schools & universities. She has augmented her training expertise having gained the Preparing to Teach in the Life Long Learning Sector qualification. She also has experience gained through working as a volunteer in a number of different roles including amenity style gardening in parks and practical conservation work.

.Maggi Brown Cert.Ed.(Environment)
Maggi is regarded as an expert in Organic Growing throughout the UK, having worked for two decades as Education Officer at the world renowned Henry Doubleday Research Association (now Garden Organic). She has been active in education, environmental management and horticulture across the UK for more them three decades.

Yvonne Sharpe RHS Cert.Hort, Dip.Hort, M.Hort, Cert.Ed., Dip.Mgt.
Over 30 years of experience in horticulture, education and management, Yvonne hastravelled widely within and beyond Europe, and has worked in many areas of horticulture from garden centres to horticultural therapy. She has served on industry committees and been actively involved with amateur garden clubs for decades.

Thady Barrett M.Hort (RHS) Thady is a consultant to the horticulture industry in the UK, with particular interest in the ornamental plant sector. Previously a senior lecturer at Writtle College for 20 years which included being course tutor for RHS qualifications. Wide ranging practical horticultural experience but with specific interest in propagation techniques and plant production technologies. Member of the International Plant Propagators Society (IPPS) and awarded the Rose Bowl Award in 2009 in recognition of his contribution to the society

 

Lesson Structure

There are 10 lessons in this course:

1. Approaches To Land Rehabilitation
2. Ecology Of Soils And Plant Health
3. Introduction To Seed Propagation Techniques
4. Propagation And Nursery Stock.
5. Dealing With Chemical Problems
6. Physical Plant Effects On Degraded Sites
7. Plant Establishment Programs
8. Hostile Environments
9. Plant Establishment Care
10. Rehabilitating Degraded Sites

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

• 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.

What You Will Do

• Determine ten different examples of land degradation on sites visited by you.
• 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, landcare 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 sites, including:
  • 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 tubestock, 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 tubestock plant, according to the production schedule developed by you.
• Estimate the differences in per plant establishment costs, for tubestock, 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.
• 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.

---

Plant Legumes to Build Up Soil Nitrogen

Examples include:

ACACIA (Wattle)      Family (Mimosaceae)

Approximately 800 species. from a wide range of climates. You can find a wattle to suit almost any climate or situation. There are small shrubby wattles, low growing or prostrate types suitable as groundcovers or to spill over a drop, spreading bushy shrubs, upright narrow shrubs or small trees and more. Most have very attractive golden or bright yellow flowers.

Leaves either bipinnate or leaf-like structures (called phyllodes) which resemble simple leaves (but are actually expanded petioles). Flowers are usually yellow in small balls or cylinders, and prolific.

Acacias generally adapt well to low fertility soils, but very good drainage is important. Most species are fairly tolerant of dry conditions. Most are very quick growing. Seedlings may be planted out when they are about 15cm tall. Most seedlings will flower in the first or second year. Fertilise lightly with blood and bone when planting and water in. Mulch is beneficial, particularly in drier areas. Protection from grazing using tree guards may be necessary. Tip pruning after flowering helps maintain bushy growth. As a fast growing plant, it might need hard pruning if the shape becomes straggly, particularly in shadier sites. Regular light pruning may extend the lifespan of some Acacias considerably. Some species are frost sensitive when young. Most Acacia species, with the exception of a few of the taller species are short lived.

Acacias are legumes fixing nitrogen into the soil that benefits other heavy feeders. Flowers attract bees and birds. They are excellent, quick growing pioneer plants, for disturbed or degraded areas, providing protection for slower growing, or less hardy species, then usually dying or thinning out once the other species are established. Some acacia species (e.g. A. baileyana, A. longifolia) have become extensively naturalised in areas outside of their natural range, and, have the potential to become environmental weeds.

Propagated from seed treated by immersion in water that has just been boiled, and left to stand overnight or for at least 12 hours. Fertile seeds will begin to swell and may be used immediately, the others can be treated again. Seeds may also be scarified to hasten germination. Use of smoke water has had good results. Cutting are generally difficult for Acacias, although species with short phyllodes propagate fairly well from cuttings.

Pests include Borers and Gall Wasps. Diseases are rare and normally not serious, although rust galls are relatively common. Cut out and burn affected parts.

Cultivars
Even though some wattles are large trees, and others small shrubs, many are small trees, suitable for small gardens. Some examples are:

Acacia acuminata (Jamwood wattle) : 3-6m tall, avoid lime soils, tolerates wet soil, weeping branches, narrow leaves rich yellow flowers in late winter. Slow growing.

A. adunca (Wallangarra wattle) To 6m tall x 2 – 2.5m wide. Long narrow phyllodes,
often drooping.

A. aneura (Mulga) to 6-7m tall. Attractive, greyish, generally narrow phyllodes to 8cm
long, and yellow rod-like flowers mainly in spring. Prefers full sun, and dry conditions.

A. baileyana (Cootamundra wattle) Highly desirable small dense tree 5-8m with silver-
grey foliage and a profusion of golden yellow blooms in winter-spring.

A. deanei Small tree of 5m with long racemes of pale yellow flowers in May to March.

A. fimbriata (Brisbane fringe wattle) Small bushy shrub/tree 3-6m with small pale yellow
flowers. Phyllodes have a delicate fringe on their edges.

A. floribunda (White sallow wattle) Sometimes dense small tree to 6m with long
phyllodes and rod-like fragrant pale yellow flowers.

A. longifolia (Sallow wattle) Very fast growing, spreading small tree to 5-8m with long bright green phyllodes and bright yellow blossoms.

A. podalyriifolia (Mount Morgan /Qld silver wattle) Quick growing highly attractive small
tree to 5m with silver grey foliage and fragrant bright golden yellow blooms.

A. pycnantha (Golden wattle) Popular small pendulous tree 5-8m and highly attractive
globular scented golden yellow blooms.

A. saligna (Golden wreath wattle) Fast growing small tree 6- 8m with semi-pendulent
branches and slightly curved phyllodes. Globular bright golden yellow flowers in axillary racemes.

A. spectabilis (Mudgee wattle) Highly attractive small tree to 5m with stunning flowers in
winter and spring. Slightly weeping habit. Needs excellent drainage.

Albizia            Family: Mimosaceae

Between 100 and 150 species, many are tropical or sub-tropical plants.

They generally resemble Acacias (wattles). Some species are very tall, others are more appropriate for smaller gardens. Leaves are normally bipinnate, often fern-like. Flowers are plume-like, and white, green, yellow or pink in colour.

They are generally very fast growing, and sensitive to extreme cold or dryness while establishing. Ideally grown in sandy or gravelly soils, but they will adapt to any reasonably well drained soil. They will tolerate mild drought and temperatures to minus 5 degrees Celsius once established.

Most can be pruned by up to half their height annually. The fast regrowth keeps the plant healthier and looking better. Without regular pruning, many can be relatively short lived, and become sparse lower down. Avoid excessive mulching. They are prone to borers.

Cultivars
A. julibrissin –to 9m, this is generally inappropriate for small gardens.

A. distachya (syn. A. lopantha) –3 to 8 metres, very fast growing (it can reach full size in 1-2 years), but may only live 6 or 7 years. Specimens that live a long time often become sparse and ugly. Will often stay shrub-like in appearance when grown in harsh conditions. Yellow brush like flowers; will self seed easily and may become a pest in light soils.

 

Erythrina    Coral Tree         Family Fabaceae

A large genus of around 100 species, the flowers of some species are cooked and eaten, some have medicinal properties, and some are poisonous. Some are small, some tall. They are mainly tropical; most are woody, some herbaceous with young growth dying back to a greater or lesser degree after harsh conditions, only to regrow when conditions improve. Most are deciduous and have compound, trifoliate leaves. Many have short thorns. Flowers are pea-shaped, in racemes, and mostly red or yellow in colour, and often very showy, followed by hard, oval globe or elliptical shaped pods. Grown primarily for their showy flowers.

Some are very hardy; most prefer well drained soils and shelter from strong winds, but plenty of light (full sun is ideal). Many tolerate dry periods, but some will like plenty of moisture when putting on growth. They generally develop a tap root that makes them difficult to transplant. Prune to shape (herbaceous types should have dead or soft wood, pruned back at the end of the growing season, in preparation for the next seasons re-growths).They are susceptible to a few fungal diseases, including root rots, wilt and blight; and occasionally root nematodes; but overall, pests and diseases are not common.
Propagate from hot water treated seed, and by hardwood cuttings of woody types in winter.

Cultivars
E. crista-galli - 4 to 5m tall, deciduous, showy red flowers, occasional prickles, a spreading crown to 8m diameter.

E. heardii -6 to 8m tall, deciduous, flowers in winter or early spring, suits very dry climates.

E. phebocarpa - 5-6m tall, orange red flowers occur before leaves emerge at the end of winter (in warm areas) or in spring (in cooler districts).

E. X sykesii (Indian Coral Bean) -a hybrid between Australian and South African species; to 6m tall, deciduous, profusion of scarlet flowers late winter or early spring, does well in temperate Australia and New Zealand.

 

Sophora     Family   Fabaceae

There are about 50 species, both evergreen or deciduous shrubs or trees. They often have attractive divided leaves (pinnate) and open foliage, and attractive masses of usually white or yellow pea flowers in terminal panicles or axillary racemes, which are followed by long pods. They make excellent small specimen trees. Their roots are rarely a problem.

They are mostly grown in cool temperate climates, and they prefer a well drained loam, but adapt to most soils if they are not waterlogged. Full sun gives best results for both foliage and flowers. Though a temperate climate plants they like protection from extreme cold. Irrigate during periods of drought. Feeding is not normally needed, though plants may benefit from some attention in this area. Commonly trained as trees with competing leaders removed until the plant is well established. Prune lightly after flowering to remove spent flowers and promote bushiness. Pests are rarely a problem. A few diseases can occasionally occur (Canker, Damping off and Blight). Propagate easily by seed, sown when fresh, or cold stratified over winter and sown in spring. Some can also grow from cuttings, layers, and grafting of selected forms onto seedling rootstocks.

Cultivars
S. japonica ‘Pendula’  - A weeping form to 3-4m tall (note the typical species can however grow to 10m), with twisted contorted branches. Grafted onto an upright stem of the species. Masses of pea-shaped, cream flowers in summer. Hardy plant tolerating dry conditions, and poor soils, but responding well to fertilising, and additional water in summer.

S. microphylla  - A small deciduous tree, to 6m tall, with attractive fern-like foliage. Flowers are yellowish but variable in colour, occurring in spring. Less hardy than S. Japonica, preferring deep fertile soils, with regular moisture, reasonable drainage, and mild winters.

S. tetraptera (Kowhai) – To 5 to 7 m tall, with an upright non-spreading habit, pale to golden yellow flowers in late mid to late spring.

 

Visit the ACS online bookstore for books related to this subject

 

If you would like more advice on a course, then you can contact us and ask a tutor about the courses. You can contact us by calling 0800 328 4723 or +44(0) 384 442752 or emailing info@acsedu.co.uk

 

Recognition and Accreditation

For more information on our recognition and accreditation, click on “The School”, then “Recognition”.

 

Who is ACS Distance Education?

If you want to know more about ACS and our history, then please click on “The School”, then “About us.”