1887

n Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie - Belangrike faktore vir die keuse van ekotipe spesies vir veldherstelbehandeling : navorsings- en oorsigartikels

Volume 29, Issue 4
  • ISSN : 0254-3486
  • E-ISSN: 2222-4173

Abstract

Die tipe veldherstelbehandeling wat gebruik word in gedegradeerde weivelde hang van die graad van agteruitgang af. Gedegradeerde areas wat reeds verby die drumpel van natuurlike herstel is, benodig gewoonlik aktiewe ingryping. Dit sluit die versteuring van die grondoppervlak of die verwydering van ongewenste en uitheemse spesies wat kompeteer met bestaande plantegroei, in. Een van die hoofdoelwitte van veldherstel is die verhoging van weidingskapasiteit vir veeproduksie. Daar word aanbeveel dat veldherstel die hersaai van plaaslike ekotipe spesies, wat by spesifi eke grond- en klimaatstoestande aangepas is, insluit. Om saadontkieming en saailingvestiging te fasiliteer, moet 'n vorm van beskerming, soos die pak van takke of enige bedekking met organiese materiaal, ingesluit word. Die tyd van hersaai is afhanklik van die seisoenaliteit en reënval, veral in areas waar reënval onvoorspelbaar en ongereeld is. Verder is die hersaai van groot gedegradeerde areas met spesifieke ekotipe spesies grootliks afhanklik van die beskikbaarheid van saad. Dit is 'n belangrike beperkende faktor. Meeste saad, wat in die handel by saadmaatskappye in groot hoeveelhede beskikbaar is, word vir aangeplante weiding gebruik. Hierdie saad is gewoonlik nie van plaaslike ekotipe spesies, wat vir 'n sekere habitat aangepas is nie. Dit is gewoonlik nie koste- en arbeidseffektief om groot hoeveelhede saad van 'n spesifieke habitat te versamel nie. Die kwaliteit, kiemkragtigheid en suiwerheid van versamelde saad is ook gewoonlik baie laag. Dit kan lei tot swak resultate. Alhoewel die ekonomiese aspek en korttermyn resultate van veldherstel beskou word as 'n bepalende faktor, kan die ekologiese belangrikheid van die verbetering van veldkondisie nie uit die oog verloor word nie. Veldherstel moet uitgevoer word volgens 'n vooropgestelde plan en moet aspekte soos monitering en goeie bestuurspraktyke oor die langtermyn insluit.


The type of restoration application in degraded natural rangelands will depend on the degree of degradation. Degraded areas that are beyond the threshold of natural recovery normally need active restoration interventions. This includes the disturbance of the soil surface or the removal of undesired and alien species to reduce the competitive effect on the existing vegetation. One of the main goals of restoration in degraded arid and semi-arid rangelands is to increase the grazing capacity for livestock production. Active restoration interventions include re-seeding or revegetation with local ecotype selected species, adapted to the specific soil and climatic conditions of the area. To facilitate seed germination and seedling establishment, the restoration practice should also include protection measures such as brush packing or any cover by other organic matter. The timing of re-seeding is dependent on the seasonality and precipitation, especially in areas where rainfall events are erratic and unpredictable. Re-seeding of large degraded areas with specific ecotype selected species greatly depends on the availability of seed. This is a major limiting factor as most seed available from seed merchants are used for cultivated pastures, and do not include seed of local ecotype species that are adapted to a certain environment. To collect large quantities of seed represented by a specific habitat is very labor intensive and often not cost effective. Furthermore, if local ecotype selected seed is used, the quality, viability and purity are often not of a high standard, leading to poor restoration results. Although the economic implication and short term results of a restoration application are often regarded as determining factors, the ecological importance and improvement in the range condition should not be underestimated. Restoration applications have to be implemented according to a predetermined plan and should include monitoring and sound long-term management principles.

Loading full text...

Full text loading...

Loading

Article metrics loading...

/content/aknat/29/4/EJC20482
2010-12-01
2019-10-23

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error