indicators as assessed within the national park.
Figure 8. The range condition short termitaria vegetation type based on the occurrence of five indicators as assessed the national park and game management area.
important factors for site stability relevant to the site potential  and our results suggest that this vegetation type is largely susceptible to accelerated wind and water erosion. Two factors seem important to have caused this.
Firstly, Termitaria vegetation type does not regularly flood and floods may cover this area only during high flood peaks and in exceptional years, and secondly much grazing occurs in this vegetation type by large herbivores, mainly buffalo and roan antelope. Litter amount is a measure of dead plant material that
Figure 9. Percent herbage standing crop biomass production and percent grazing intensity in each vegetation type.
covers the soils and most important for decomposing and soil formation and significant for detrital food chain. The wide and even distribution of litter in all vegetation types sampled as shown in our results can only be explained by the lack of movement of litter amount in this low gradient wetland. However, this aspect requires further investigations.
Herbaceous ground cover describes the proportion of soil surface covered by grasses and forbs. These plants are most important for grazing and can either be perennial or annual and the low presence of grass cover in the area can be explained as being due to excessive grazing and that the rangeland is dominated by high presence of annual grasses which being evaders reproduce by seed and live only for one growing season.
With regard to utilization, it was evident that considerable research has been devoted to this  , which in essence refers to the degree to which animals have consumed the annual usable forage production expressed in percentages  . This is important in rangeland management primarily for estimating carrying capacity and stocking rates. As our results have revealed over 40% of the herbage produced per year is consumed by wild herbivores. Whether or not this amount could be accepted as allowable use for wildlife in Kafue Flats rangeland remains largely speculative and inconclusive. We hypothesized that Kafue Flats north bank was overstocked during the period before the construction of the Itezhi-Tezhi dam. While this view may appear conjectural, various studies    have provided sufficient discussion on spatial and temporal differences in structures of wetland landscape and the impact of grazing in a rangeland. Flood patterns, plant diversity and food availability are important determinants of the distribution of animals and these require considerable empirical evidence before conclusions can be made.
The significance of these findings however, is that we now know that Kafue Flats wetland was under severe land degradation even before the construction of the Itezhi-Tezhi dam and there are several reasons and speculations which may require discussions and future research.
First, Kafue Flats as a flood plain rangeland assumes the wetland ecological character, and understanding the relationship between grazing and wetland conditions is essential for effective management of a wetland grassland   . The data presented in this study are an important description of the Kafue Flats state before the construction of the Itezhi-Tezhi (“Meshi Teshi” as was known) dam, but full interpretation would require discussion of linkages between wetland condition and rangeland condition. Wetland condition as might apply to the Kafue Flats, refers to the health of an ecosystem that primarily supports habitats and viable native animals and plant populations similar to those present before any disturbance  , and that it is able to return to its pre-existing condition after disturbance, whether natural or human induced and that annual flood pulse, channel forming floods, and infrequent droughts remain major driving factors in flood plain river ecosystem.
Secondly, knowledge of hydrology of the ecosystem and its processes is fundamental and critical for sustainable development, in particular, if dam development and operations are to become part of an integrated management in such sensitive ecosystems that would need environmental protection. Emerging issues on the impact of dams have been widely debated and well documented    , however the main focus of concern on Kafue flats centred on limited water for the wetland and currently coupled with water regulation and altered environmental flows. The primary question is how much water is required to sustain the ecosystem in Kafue Flats wetlands-Essentially, environmental flows are understood to be the quantity, quality and timing or water flow required to sustain fresh water ecosystems and livelihood and wellbeing that depend on these ecosystem  . However, water requirement or ecological flow needs are levels required in a water body for flora and fauna and habitat process present within that water and its margins  , and aware of our inability to make meaningful evaluation of environmental flow requirement, but in trying to explain and understand the hydrology of the Kafue Flats wetland, we want to propose a number of hypotheses.
We argue that Kafue Flats sub-catchment of 45,526 km2 had much of its recharge function substantially reduced. This is because the streams within this sub-catchment are seasonal and may flow only for three to four months in a year, and in addition increasing human settlements and excessive deforestation   have resulted in recharge function largely being dysfunctional. The relationship between water and forests has well been studied and widely discussed  and clearly the vegetation around the Kafue flats is an integral part of the Kafue Flats landscape. As earlier pointed out  forests play a significant role in the interaction between ground water of wetland ecosystem and through the recharge function as well as controlling flood flows, water quality and erosion control.
Thirdly, the use of plants to measure water requirements or wetland ecosystem condition has been an established science   . Plant species presence and absence, plant vigour, plant diversity and invasiveness are among reliable indicators and tools in evaluating wetland condition. Similarly, plant response to altered and regulated water regimes have also been well investigated    . These tools are available for research in Kafue Flats monitoring.
Fourthly, water regime of a flood plain is its characteristic pattern of flooding, drying and water level changes and these water level changes have specific needs to ensure plant species maintenance and regeneration. The flood pulse ecology has emerged as the new science that has adequately provided explanations to such wetland processes. The basic claim of the flood pulse principle is that it refers to a river discharge, the flood, as the major force controlling biota in a river flood plain as the river and the flood conduct exchanges laterally between them  . Since then the principle has been well researched and discussed elsewhere    . This principle is of great interest to the Kafue Flats because of its implication on the primary production of the rangeland. The reduction on the environmental flows coupled with regulated flood pulsing through timing, duration and magnitude could have serious consequences on the annual life cycles particularly the annual grass species in this wetland  . However, this view would require detailed investigations and further substantiation.
Furthermore, although fires are known to be of great significance and a tool extensively used in wetland and rangeland management, their effects are not well understood. Whether or not fires cause changes in the structure of vegetation has been a subject of investigation and debate for a long time   . Numerous and well documented studies that have been done on the effects of fires have revealed fires as an integral part of wetland and rangeland landscapes and a management tool    , and that the effects of fire generally depend upon fire intensity, frequency, and time of the year   . Although fires may remove much of the vegetation in a wetland and can change the structure and configuration of a wetland, the removal of organic soils and change in water chemistry may have a negative effect on other organisms. We believe that research on this aspect should be pursued further.
5. Conclusions and Recommendations
This study provides earlier information of the rangeland condition of the Kafue Flats wetland before the construction of the Itezhi-Tezhi dam. Nevertheless, its significance will depend on detailed subsequent research in the future, in particular, rangeland health and pasture dynamics, environmental and ecological flows, pulse ecology and fire ecology.
For now, it is firmly establishment that rangeland research and monitoring programmes are essential to adaptive management of vegetation dynamics.
These results have also given the picture that the rangeland in Kafue Flats north bank is largely at high risk as demonstrated by high values of bare ground of the soils and that there is high possibility of the rangeland being over grazed since the recorded 40% is unsustainable in flood pulse ecosystems.
1) We recommend the establishment of regular rangeland and wetland health assessment and monitoring providing for determination of causes of plant succession most likely directing change and for managers to consider repair or restoration.
2) We also propose detailed research on both wetland and rangeland health and provide answers or suggestions in view of disturbances involving multiple factors such as environmental flow, flood pulse and human impact.
Conflicts of Interest
The authors declare no conflicts of interest.
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