Assessing technological capability of innovative stress detection tools in forestry for the improvement of commercial production: a South African perspective

Abstract

There is a constant need for efficient screening methods of plant physiological stress in nursery and plantation forestry systems. Most stress is assessed visually, which can be subjective and requires manpower that is time-consuming and expensive. However, as technology has progressed, the use of remote sensing and smart sensors has improved in providing alternatives that have become more accessible and accurate as tools for monitoring. Thermal information can be obtained from trees and offer a range of indicators such as water stress and stomatal conductance activity, where temperature has a direct influence on physiological functions, through stomatal control. Anticipated changes in climatic conditions will pose a great challenge in water availability for plant physiological purposes, and the ability for trees to adapt. This forces researchers to monitor tree activity and relay information to planning and management systems, to consider changes in tree species or to implement preventative action for loss mitigation. This paper provides a perspective on the use of smart technologies to monitor plant stress, which can be used in both nursery and forest field applications. It was found that using simple and available technologies such as hand-held and mobile cameras to record temperature and stomatal conductance provided good indicators of plant stress that may be used to predict vitality, vigour and productivity. Thus, the synergy of sensors that focus on these physiological functions of plants, regarding their water stress and temperature, should contribute well to future scientific research in South Africa, and further the advancements for efficient stress screening.