Bibliography: Land Degradation in South Africa project

the land, resulting in lower crop yields.

Ref ID : 1934

1016. Grindley, J. and Dudley, S. Estuaries of the Cape, Part 11. Report no. 28

Reitvlei (CW 24 and Diep (CW 25). CSIR research reports.Anonymous Pretoria:CSIR.

427, 1988.

Reprint : Not in File,

Ref ID : 815

1017. Grobler, D.C. and Silberbauer, M.J. Impact of eutrophication control

measures on the trophic status of South African impoundments.Anonymous

Pretoria:Water Research Commission. 130/1/84, 1984.

Reprint : Not in File,

Keywords : WATER QUALITY; POLLUTION

Ref ID : 1722

1018. Grossman, D. Primary production of rangeland: practical and interpretive

problems. Proceedings of the Grassland Society of southern Africa 17:76-78,

1982.

Reprint : In File,

Keywords : SOUTHERN AFRICA; METHODOLOGIES; VEGETATION DYNAMICS; AGRICULTURAL

PRODUCTION; LIVESTOCK PRODUCTION

Abstract : Primary production of rangeland has not been studied in southern

Africa to the extent that it has been in other biogeographical regions.

Ambiguity in terminology and in conceptualization of the process created

difficulties in interpreting and/or comparing production data within the region.

Certain difficulties inherent in estimating primary production of perennial

natural rangeland are discussed. Harvest data are utilized to illustrate how

methodology employed is critical to the estimate of primary production obtained.

A relationship is presented which accounts for the major losses pertinent to

most methods of estimating rangeland production.

Ref ID : 1291

1019. Grossman, D. Game ranching.Anonymous Anonymous Pretoria:Department of

Agriculture and water Supply. :1-3, 1989. 0 621 11412 X.

Reprint : In File,

Keywords : CONSERVATION

Notes : As a relatively young industry, a great opportunity exists to learn from

the mistakes of the past and to avoid the pitfalls which befell other farming

enterpresises. A vital game production industry, making wise use of the

country's natural resources, can contribute to the stability of rural areas,

provide sought-after products and add to the overall success of agriculture and

conservation.

Ref ID : 1334

1020. Grossman, D. Wildboerdery. Weading: 'n stategie vir die toekoms.Anonymous

Anonymous Pretoria:Departement van Landbou en Watervoorsiening. :1-4, 1989. 0

621 11411 1.

Reprint : In File,

Notes : See notes on the English translantion in ID no 1291 "Game Ranching".

Ref ID : 928

1021. Grossman, D. and Gandar, M.V. Land transformation in South African savanna

regions. South African Geographical Journal 71(1):38-45, 1989.

Reprint : In File,

Keywords : LAND DEGRADATION; BUSH ENCROACHMENT; SAVANNA; LAND USE

Abstract : The major form of land-use in savanna regions, which occupy about one

third of the surface area of SA, is pastoralism. Deterioration of the

herbaceous layer and an increase in bush density are regarded as the major

transformation processes in commercial ranching areas. In subsistence

economies, denudation of vegetation due to grazing and wood use are problems.

The socio-economic factors underlying these transformations are described.

Ref ID : 916

1022. Grut, M. Notes on the history of forestry in the Western Cape 1652-1872.

South African Forestry Journal (100):32-37, 1977.

Reprint : In File,

Keywords : FORESTRY; WESTERN CAPE; ENVIRONMENTAL HISTORY; FOREST

Abstract : A brief account is given of forestry history in the South Western

Cape Province from the time of the first permanent European settlement until the

granting of self-government. The demand and supply of wood, the indigenous

forests, forest law, and afforestation are dealt with. The scanty indigenous

forests were almost from the outset insufficient to meet the demands of the

settlement for firewood and building timber. The authorities therefore

immediately began trials with a view to finding exotic or indigenous tree

species suitable for afforestation. Exotic species used in these early trials

were, in chronological order: alder (Alnus glutinosa), Norway spruce (Picea

abies), Scots pine (Pinus sylvestris), ash (Fraxinus excelsior), oak (Quercus

robur), hazel (Corylus sp) and teak (Tectona grandis). Indigenous species were:

wild almond (Brabeium stellatifolium), "kreupelboom" (Leucospermum

conocarpodendron) and, probably, mountain cypress (Widdringtonia cupressoides).

Of all these, only the oak proved really successful, and was then extensively

planted in plantations, as a street tree, and singly, especially during the

period 1679 - 1706.

Ref ID : 1489

1023. Habitat Council The planning and conservation of the dry regions in South

Africa.Anonymous Anonymous , 1984.

Reprint : Not in File,

Keywords : CONSERVATION; DESERTIFICATION CONTROL; VELD MANAGEMENT; WATER

CONSERVATION; EROSION CONTROL

Ref ID : 1459

1024. Haigh, H. Grassing roads and eroded areas in the Drakensberg. South

African Forestry Journal 97:63, 1976.

Reprint : Not in File,

Keywords : EROSION; RESTORATION

Ref ID : 666

1025. Hakkeling, R.T.A. Global assessment of soil degradation - eastern and

southern Africa. Main Report (2 volumes).Anonymous Wageningen:STIBOKA. , 1989.

Reprint : Not in File,

Keywords : SOIL EROSION; LAND DEGRADATION; SOUTHERN AFRICA; STATISTICS

Ref ID : 166

1026. Hall, T.D. South African pastures: retrospective and prospective. South

African Journal of Science 31:59-97, 1934.

Reprint : In File,

Keywords : KAROO DESERTIFICATION; STOCKING RATE; DESERTIFICATION ASSESSMENT;

VEGETATION CHANGE; VELD MANAGEMENT; EROSION

Notes : The author writes that SA is at last realising that she is primarily a

pastoral country and is now almost quite disillusioned about her youthful

ambitions of becoming a second Argentine as regards maize production. Huge sums

of money have recently been appropriated by the government for pasture

investigations, veld management studies, erosion prevention and control, and the

eduction of farmers and the younger generation to the necessity of immediate and

vigorous action if SA is to be saved from becoming a desert. Little time will

be devoted to prospective pastures as the veld and the grasses composing it have

been ably dealt with by other writers from the ecological, phytogeographical and

taxonomic aspects. In this article, pastures will be dealt with more from the

point of view of their exploitation and mismanagement by man in his struggle for

existence.

Ref ID : 167

1027. Hallet, R. Reflections on a dust storm in the Free State. ?Cape Times ,

1990.

Reprint : In File,

Keywords : SOIL EROSION; DESERTIFICATION ASSESSMENT; FREE STATE; EROSION

Notes : The reporter agrees with the sentiments of a reader who wrote of the

tragedy of sand storms in the Free State being symptomatic of soil degradation.

He draws a parallel between these dust storms and the radioactive lichens in

Lappland as indicators of humans prioritising technological advance over the

survival of life. While he points out that philosophers like Heidegger may

argue for "existential revolutions" he prefers to support more practical tactics

like tree planting schemes to combat soil erosion.

Ref ID : 301

1028. Hallward, J.R. An investigation of the areas of potential wind erosion in

the Cape Province, Republic of South Africa.University of Cape Town. , 1988.

Master of Science.

Reprint : In File,

Keywords : SOIL EROSION; DESERTIFICATION ASSESSMENT; WESTERN CAPE; NORTHERN

CAPE; EASTERN CAPE; WIND EROSION; MAPS; EROSION; MODELS; RAINFALL; RUNOFF; VELD

CONDITION; CONSERVATION

Notes : Only a few pages have been copied. The conclusions reached are that

from the methods used in this study it is not possible to produce a clear map of

the wind erosion hazard in the Cape Province. It is of interest to note that

although neither of the models indicate that there is a severe wind erosion

hazard in the Cape Province, observations and reports indicate otherwise. The

author goes as far as to suggest that virtually the entire province, with the

possible exception of the all year rainfall zone and the forested areas, is

susceptible to wind erosion. This conclusion is based on observations made

while driving through various parts of the province and from comments made by

various individuals through the course of the research. For example, the

susceptibility of the Cape Flats area to the east of Cape Town has been clearly

illustrated by the problems of blowing sand during the extensive road

construction that has been ongoing for the past few years. The complaints of

the residents of Khayalitsha and of communities on the western side of Cape Town

will also attest to the problems of wind erosion. This, however, need not be an

ongoing problem, as once construction has been completed and vegetation has been

established, much of the blowing sand should be controlled. A close examination

of many parts of the Karoo, on the other hand, will reveal ripple marks on

exposed areas, the accumulation of sand and debris at the base of bushes and

where sand blasting is severe the loss of bark on the downwind side of some

bushes. This is evidence that wind erosion has been a long term problem. That

the problem goes unnoticed by people in many areas including the Karoo is not

surprising due to the insidious nature in which the effects of wind erosion

accumulate. Nonetheless it is surprising that the models fail to adequately

reflect actual conditions. It is for this reason that the author concludes that

in the Karoo and inland areas of Namaqualand, management is the primary factor

responsible for wind erosion. Acocks (1953, 5 - 6), in his oft quoted treatise

on the Veld types of SA discusses the effect of improper management. He regards

continuous selective grazing as having had three main impacts on the Karoo.

Firstly, it has changed the species composition of the veld so that good grazing

species have been replaced by less useful ones. Secondly, soil cover has been

reduced giving rise to a loss of water through run-off, sheet erosion and wind

erosion. The net result is a silting of rivers and a scouring of channels which

has increased donga formation. It thus appears that the effects of improper

management have long been an issue of concern and that even in the 1950's it was

apparent that management was a significant factor in giving rise to erosion and

veld degradation. SA is an arid country. Most of the Cape Province falls into

either a summer or winter rainfall zone and as a result different parts of the

province are particularly arid at different times during the year. It is during

the dry season that the wind erosion hazard is most severe. SA also experiences

a cyclical rainfall pattern of 18-20 years duration. It is during the 9-10 year

dry period that the wind erosion hazard is greatest. Climatic data are

notoriously poorly behaved in their statistical properties. As a result they

should be regarded with caution and not used for predictive purposes.

Nonetheless as veld conditions cannot be changed immediately it seems important

that management guidelines be based on maintaining an adequate ground cover

during the drier years so as to avoid excessive erosion during these periods.

It is suggested that further research is required with regard to grazing

management in the Karoo. It is essential that one of the goals of management be

veld conservation in order to improve and retain the productivity of the Karoo.

It is only by doing so, that the threat of increasing desertification of which

wind erosion is only a part, can be brought under control.

Ref ID : 453

1029. Hanbidge, G. A study of gully erosion: a Natal donga. Unpublished third

year student report. Geographical & Environmental Sciences, University of Natal,

Durban. 1983.

Reprint : Not in File,

Keywords : SOIL EROSION; KWAZULU NATAL

Ref ID : 1936

1030. Hanbidge, G. A study of gully erosion: a KZN donga. 1983.

Reprint : Not in File,

Keywords : EROSION

Notes : An unpublished third year student report, Geographical and Environmental

Sciences, University of KZN, Durban.

Ref ID : 1419

1031. Hanekom, F. Draft national enviromental management bill. Government

Gazette 397(19031):1-48, 1998.

Reprint : In File,

Keywords : POLICY; GOVERNMENT INITIATIVES; LEGISLATION; ENVIRONMENTAL POLICY

Ref ID : 850

1032. Hanvey, P.M., Dardis, G.F., and Beckedahl, H.R. Soil erosion on a

subtropical coastal dune complex, Transkei, southern Africa. Geojournal

23(1):41-48, 1991.

Reprint : In File,

Keywords : SOIL EROSION; TRANSKEI

Ref ID : 849

1033. Hanvey, P.M., Dardis, G.P., and Beckedahl, H.R. Gully development in

coastal dune systems, Mbolompo Point, Transkei, Southern Africa. Geojournal

23(1):41-48, 1990.

Reprint : Not in File,

Keywords : TRANSKEI; SOIL EROSION

Ref ID : 2017

1034. Harding, G.B. and Bate, G.C. The occurrence of invasive Prosopis species

in the north-western Cape, South Africa. South African Journal of Science

87:188-192, 1991.

Reprint : Not in File,

Ref ID : 1174

1035. Harding, G.H. The genus prosopis as an invasive alien in South

Africa.University of Port Elizabeth. :i-195, 1988. Prosopis species are thicket

forming trees or multi-stemmed shrubs belonging to Fabaceae. They were

introduced into southern Africa in 1894 as fodder and shade plants but have

since invaded vast areas of the arid north-western Cape. The taxonomy of the

species found in SA is discussed, suggesting that there are two distinct groups

present, namely invasive and non-invasive forms. The invasive group consists of

P. Velutina, P. glandulosa var. torreyana and P. juliflora. The non-invasive

group consists of P. chilensis and P. glandulosa var. glandulosa. The

possibility of hybridization between these species is mentioend but not

confirmed. The distribution of the species was determined by a postal survey,

herbarium specimens and a limited collection. This showed that the centre of

spread is the Kenhardt/Carnarvon district but that there is a large area over

which the trees are scattered. The actual area estimated to be covered with

Prosopis is 20 000 ha. The area of potential spread and the pattern of spread

were determined from Landsat Images. This showed that the potential area

available for Prosopis is about 935 000 ha. The pattern of spread was

determined using aerial photographs of the farm Humansdam and was found to be

directly related to above-normal rainfall events. The type of soil does not

influence the distribution of the trees but the soil depth and availability of

ground water does. Boreholes were used to collect sediment samples while a

hammer seismograph was used to determine sediment depth. This showed that

Prosopis has a phraetophytic habit and can be expected to be a problem in areas

with either shallow groundwater and deep sediment or areas with high rainfall.

The germinability of the seeds was investigated using acid and boiling water

scarification. This showed a requirement for scarification and that acid was

more effective than boiling water. Once scarified the seeds germinate readily,

have no light requirement but do have a temperature requirement with 30/20oC

(day/night) being most effective. Seeds exposed in the field were found to

decay rapidly when buried at 10 cm., with 98% damage being recorded after 18

months. Damage to seeds on the soil surface was considerably lower with only

58% of the seeds being destroyed in that time period. The effect that domestic

and wild animals have on seed dispersal was investigated over a 1 km2 plot.

These data suggest that porcupine and bat-eared fox with 7,38 and 2,53 seeds g-1

dung respectively are the major distributors of seeds. However the distance

over which they spread the seed is limited. Domestic stock have only 0,0335

seeds g-1 dung but their range is considerably greater. The potential of

Prosopis pods as a sheep feed was investigated. Sheep mass gains were monitored

as well as the number of undamaged seeds passed in the faeces. This showed that

although Prosopis pods are suitable as a feed, they should not be used

continuously as this resulted in fluctuating mass gain and decreased seed

damage. The extent of damage to seeds varied between sheep and with time, with

a mean of 92,5% seeds being rendered non-viable. Chemical control was

investigated using aerial foliar-applied herbicides, with Knapsacks and with a

high pressure, low volume foam applicator. Cut-stump and soil application were

also included. Cut-stump proved the most effective while extreme climatic

conditions made foliar application difficult and only moderately successful.

The efficacy of herbicides applied to the soil is erratic because of limited and

erratic rainfall. Trees that have rooted into the groundwater i.e. those

growing as phraetophytes are not as stressed as those growing on the fringes of

the Carnarvon Leegte. Pre-dawn water potential values of phraetophytic trees

were found to be about -1,0 MPa and dropped to -2,7 MPa at midday. Trees with

water potential values as slow as -5,5 MPa were presumed to be growting non-

phraetophytically. Photosynthetic studes showed that Prosopis has a light

compensation point of more than 80 micro-mols m-2s-1. The daily photosynthetic

pattern of Prosopis showed a midday peak of 14 micro mols CO2 m-2s-1. The

status of Prosopis as a weed is discussed and the data used to determine whether

Prosopis is an undesirable or economic plant.Doctoral Dissertation.

Reprint : In File,

Keywords : ALIEN PLANTS; SOUTHERN AFRICA; RAINFALL

Ref ID : 2147

1036. Harding, W.R. The ecology of some urban-impacted coastal vleis on the Cape

Flats near Cape Town, with special reference to phytoplankton

periodicity.University of Cape Town. , 1992.

Reprint : Not in File,

Notes : Unpublished M.Sc. thesis, Freshwater Research Unit, Zoology Department,

University of Cape Town.

Ref ID : 1831

1037. Hardy, M.B. Short-term effects of cattle-to-sheep ratio and stocking rate

on patch grazing in sour grassveld. African Journal of Range and Forage Science

12(3):121-127, 1995.

Reprint : In File,

Keywords : STOCKING RATE

Abstract : The short-term effects of stocking rate (AUE ha-1) and cattle-to-

sheep ratio on the extent and severity of patch grazing and on patch size were

evaluated. The extent of patch grazing was proprotional to stocking rate, and

livestock species had a small but significant effect. Patch size was also a

function of size distribution when stocked at the same number of AUE ha-1. The

severity of grazing within a patch was influenced by both stocking rate and

cattle-to-sheep ratio. Recommendations that cattle should be in greater

proportion (in terms of AUE ha-1) than sheep, which are aimed at limiting the

severity of grazing by sheep, are supported. However, severe grazing within

patches is an inevitable consequence of sheep grazing irrespective of the

stocking rate or cattle-to-sheep ratio implied.

Ref ID : 1059

1038. Hardy, M.B. and Hurt, C.R. An evaluation of veld condition assessment

techniques in Highland Sourveld. Journal of the Grassland Society of southern

Africa 6(2):51-58, 1989.

Reprint : In File,

Keywords : VELD CONDITION; GRASSLAND; KWAZULU NATAL

Abstract : An evaluation of six methods used to index veld condition showed that

the majority provided indices that were insensitive to long-term grazing impact.

However, certain species were found to either increase or decrease in relative

abundance with an increase in grazing intensity. A key species method is

therefore suggested to be a potentially sensitive approach for indexing veld

condition in relation to grazing management in the Highland Sourveld.

Ref ID : 1788

1039. Hardy, M.B. and Mentis, M.T. Grazing dynamics in sour grassveld. South

African Journal of Science 82:566-572, 1986.

Reprint : In File,

Keywords : MODELS; LIVESTOCK PRODUCTION; CARRYING CAPACITY; STOCKING RATE

Abstract : Present understanding of local grazing ecosystems is based on studies

focused on single components and processes in relative isolation. The

mathematical stimulation presented here is intended to relate components and

improve the testability and predictive capacity of theory. The model simulates

(1) the response of the species composition of the veld to grazing livestock,

and (2) livestock production from veld. It is assumed that grazing intensity

affects floristics because of the variable tolerance of plant species to

grazing. Further, animal performance is assumed to depend partly on floristics,

since plant species differ in palatability and nutritive value. Modelled animal

production per hectare is not universally better under rotational than under

continuous grazing, the latter being of merit for veld in 'poor' condition.

Both commercial and subsistence graziers are locked into 'overgrazing'. The

seasonal production of forage sensitively affects animal performance, implying

the importance to modelling of grass growth and its response to grazing. A

single value for the carrying capacity of veld for livestock is not evident.

The optimal stocking rate, the determination of which the model can facilitate,

depends on the grazier's objectives, the starting state of his veld, his

management system and economic circumstances.

Ref ID : 1062

1040. Hardy, M.B. and Walker, R.S. Determining sample size for assessing species

composition in grassland. Journal of the Grassland Society of southern Africa

8(2):70-73, 1991.

Reprint : In File,

Keywords : VELD CONDITION; GRASSLAND; MONITORING

Abstract : Species composition is measured in grasslands for a variety of

reasons. Commonly, observations are made using the wheel-point apparatus.

However, the problem of determining optimum sample size has not yet been

satisfactorily resolved. In this study the wheel-point apparatus was used to