This June, Arboriculture students from Bridgwater & Taunton College attended a workshop on urban tree planting and the problems faced by arborists when planting in what is considered a fairly hostile environment for plants. Green-tech, a company specialising in urban landscape products provided the learners with information regarding latest developments in specialist tree planting.
The potential problems facing trees in urban environments are poor soils in terms of physical and biological characteristics, soil compaction and inadequate irrigation.
Barry Browne, Technical Specification Manager, was very helpful in giving students an insight into the importance of using quality soils in urban environments to ensure successful tree establishment. This was further enhanced by the students being able to look at soil samples including what is termed a ‘manufactured’ top soil using organic compost and sand from quarries.
Within the urban realm, providing trees with enough water is a constant problem particularly during periods of drought. There are huge costs associated with adequate irrigation, hours spent manually watering and litres of water wasted. Barry covered some of the systems that have been in use within the landscape sector over the last few years. One of these, the Mona Irrigation System developed in Sweden, makes use of simple underground storage containers underground. These work by acting as a water reservoir providing water to tree roots when required via capillary action. The system is very simple and easy to install but eliminates overwatering, water wastage and reduces watering frequency.
Additionally, in urban environments, soils are very much prone to compaction. Soil compaction is detrimental to healthy root growth. It alters the physical properties of soil, impeding the movement of water and air. Compaction is also harmful to beneficial mycorrhizae, the symbiotic fungi that are associated with plant roots that help in nutrient uptake. How do arborists ensure that tree roots are protected from compaction and what measures are currently used in industry to combat this? Barry highlighted one method of preventing soil compaction in the root zone. The ArborRaft System consists of a series of very strong geo-cellular units that fit together to form a raft. It is used where there is anticipated vehicle activity, ensuring that a healthy growing space is available for trees. The raft itself sits within the tree pit and helps to support and spread the load of vehicle movements over the rooting area. Each unit acts as air gaps, steering roots away from paving towards nutrient rich soil. The system helps to maintain the open structure of soil and allows trees to successfully develop a healthy root system that reflects growth and spread of canopy.
During the seminar, the students gained valuable experience of current thinking and practices used in urban tree planting with opportunities for them to engage with a company that is involved in innovative product development and implementation. In future, it is anticipated that the students will be able to either visit sites where some of these systems are being put into place or take part in practicals that allow them to experience installation on site.
If you enjoy working outdoors, a career in Arboriculture may be for you. Find out more about studying Arboriculture with us here or call the Information & Guidance team on 01278 441234.