An ecological approach to the reclamation and improvement of arid rangelands using adapted fodder plants

Abstract

The world we live in is changing rapidly. Ecological, economic and social aspects and understandings are all undergoing paradigm shifts. Communities, farmers and individuals in arid zones are experiencing climate changes, more so than city dwellers. A better understanding of the current thinking in range ecology and management, especially of arid environments, is critical to the management of these delicate, complex systems. Ecosystems in equilibrium or in disequilibrium react differently to management and reclamation efforts. An understanding of the basic principles and how they evolved is important in order to apply these principles correctly in the management of arid zones. The use of keystone species and simple technologies, such as water harvesting and mulching, can all be used to reclaim and manage the arid zones. Understanding the differences between systems in equilibrium and disequilibrium can be used as a guide for planning appropriate future research in the arid zones. Searching for new indigenous species to help in the reclamation of arid zones is of the utmost importance. An ecological criterion was used to identify potential plant species for reclamation of degraded arid rangelands of southern Africa. Tripteris sinuatum and Sutherlandia microphylla were identified as possible candidates. Germination studies, with seeds harvested from naturally occurring plants, were conducted for both species. Treatments were based on the natural seed dispersal mechanisms for both species. S. microphylla has the potential to become an important plant species for reclamation purposes in arid zones of southern Africa. Not only potential new species should be sought, but also the management of species, already in use, are of critical importance. The relative palatability and survival of 16 different Atriplex species and accessions were determined at two different localities in the arid Northern Cape Province of South Africa. Significant differences were found between species at both localities. It is believed that because of the variety of species in the Atriplex genus, relative palatability and survival should be used to determine which of the different species could be useful under specific climatic and soil conditions. The establishment and reaction of Atriplex nummularia and Cassia sturti were tested for season of planting and the use of a stone mulch at two locations in the Northern Cape Province of South Africa. A. nummularia reacted the best to a moderate pruning treatments, while Cassia sturtii reacted best to severe pruning. These results should aid in the management of planted fodder plantations. Numerous attempts at improving natural veld have failed in the past. An examination of landscape function and the potential to harvest water in localized areas should drive veld improvement in arid zones. Seeds from two different plants species (Tetragonia calycina and Tripteris sinuatum) were used to inter-seed a bare patch in the Northern Cape Province of South Africa. The two species, with two treatments, (brush packing or not) in two different locally occurring eco-topes, were used to determine plant establishment. The water run-on eco-tope showed a significantly higher plant establishment percentage than the water run-off eco-tope. The establishment of perennial grass species was also found on the water run on eco-tope, three years after establishing the reclamation site. Such sites could form an important link in biodiversity conservation.