How Do We Rehabilitate Degraded Land Sites
Land rehabilitation begins with learning to understand the processes that cause degradation, then applying counter measures to halt those processes. Greater awareness and good education is always the starting point for solving these problems. There are a number of common sense strategies that should be adopted during the planning stage that will enhance the likelihood of a successful rehabilitation project.
Firstly, the site needs to be identified and defined. What is meant by this is that visual and physical reconnaissance needs to be undertaken so that any potential problems and future impacts will be anticipated and therefore dealt with. This will need to be done in the form of an Environmental Assessment Audit from which a report will be written i.e. an Environmental Assessment Report (as discussed previously).
Regulations and guidelines exist in many countries governing Environmental Assessments. Assessments on public land will always be undertaken by experts appointed by local government authorities. The report will define the area being studied in terms of environmental significance, environmental damage and the general state of the site including resident remnants of fauna and flora species. From this initial assessment the environmental rehabilitation program can be developed that best suits the needs of the site and local environment generally.
On private land you can employ a consultant to carry out such work or discuss guidelines with your local government authority and undertake your own assessment, then develop a program suited to your land.
Tests need to be carried out on soil type and composition.
Research done on weather characteristics, resident and introduced species, and present and future land use activities.
It is important to understand the state of the local environment, because it may have changed markedly, and have very different factors at work since the degradation occurred. Species of vegetation that once thrived may be severely affected by the current state of the local environment.
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 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:
- Alkaline soils – these are soils with a pH greater than 7
- 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
- Salinity – in some parts of the world, this is a problem not just in agricultural areas, but increasingly in urban fringe areas
- Strong winds, poor soils and salty conditions associated with coastal areas
- Windy areas
- Hot, dry areas.