Bibliography: Land Degradation in South Africa project

and interpretation of information on Late Pleistocene and Holocene

palaeoclimate. At the meeting regional rapporteurs summarised the data for each

of six time zones, and after each summary the evidence was open for general

discussion amongst the 80 or more delegates. A brief resume of the results of

these discussions is given here, J Deacon being responsible for the Cape

ecozone, N. Lancaster for the Kalahari and Namib, and L Scott for the central

and eastern interior.

Ref ID : 2279

734. Deacon, J.C.G. Human settlement in South Africa and archaeological evidence

for alien plants and animals. In: The ecology and management of biological

invasions in Southern Africa, edited by Macdonald, I.A.W., Kruger, F.J., and

Ferrar, A.A.Cape Town:Oxford University Press, 1986,p. 3-19.

Reprint : In File,

Keywords : ALIEN PLANTS; SOUTHERN AFRICA

Ref ID : 2005

735. Dean, S.J., Holmes, P.M., and West, P.W. Seed biology of invasive alien

plants in South Africa and South West Africa/Namibia. In: The ecology and

management of biological invasions in southern Africa, edited by Macdonald,

I.A.W., Kruger, F.J., and Ferrar, A.A.Cape Town:Oxford University Press, 1986,p.

157-170.

Reprint : Not in File,

Keywords : ALIEN PLANTS; SOUTHERN AFRICA

Ref ID : 951

736. Dean, W.R.J. Effects of animal activity on the absorption rate of soils in

the southern Karoo, South Africa. Journal of the Grassland Society of southern

Africa 9(4):178-180, 1992.

Reprint : In File,

Keywords : HYDROLOGY; GRAZING EFFECTS; RUNOFF; SOIL PROPERTIES

Notes : The rates of absorption into various microsites in Karoo soils were

compared. The absorption of water by hard, bare intershrub soils was

significantly increased by the presence of emergence holes of adult cicadas

(Homoptera: Cicadidae) and near nest-mounds of the harvester ant Messor

capensis. Both these insects play an important role in raising the amount of

water that penetrates into the soil after rains. Absorption rates were also

high in the soils of heuweltjie mounds but were reduced by sustained use of an

area by sheep and were particularly poor on sheep paths.

Ref ID : 258

737. Dean, W.R.J., Hoffman, M.T., Kerley, G.I.H., and Milton, S.J.

Desertification in developed countries: in search of the silver bullet. South

African Journal of Science 91(5):213-215, 1995.

Reprint : In File,

Keywords : POLICY; KAROO DESERTIFICATION; DESERTIFICATION CONTROL

Notes : This article arose out of a workshop and symposium on desertification in

developed countries, the first of two planned meetings on the theme that took

place in Tucson, Arizona in 1994, and the second of the two meetings, on

desertification in developing countries is scheduled for 1997. The present

meeting addresseed the question of controlling desertification, with the

objectives of (1) identifying social, economic, political and institutional

factors that have resulted in successful interventions, (2) assessing the extent

of desertification, and (3) identifying specific techniques that have been tried

and used to slow down or reverse various desertification processes.

Ref ID : 195

738. Dean, W.R.J., Hoffman, M.T., Meadows, M.E., and Milton, S.J.

Desertification in the semi-arid Karoo, South Africa: review and reassessment

(Review). Journal of Arid Environments 30(3):247-264, 1995.

Reprint : In File,

Keywords : DESERTIFICATION ASSESSMENT; KAROO DESERTIFICATION; POLICY;

ENVIRONMENTAL HISTORY; VEGETATION CHANGE; MONITORING

Abstract : The concept of desertification has recently been re-evaluated with

two major outcomes. Firstly, the term itself has been reviewed, with most

authors concluding that the emotive implications of 'desertification' (i.e.

advancing deserts per se) are inappropriate in many cases and that the general

term 'dryland degradation' is a more accurate description of reality. Secondly,

it has been argued that the extent, nature and apparent irreversibility of the

process has been over-estimated and that degradation in some areas may only be

temporary, consequent upon an unfavourable combination of climatic and

anthropogenic factors. In southern Africa, a reassessment of the concept of

desertification is long overdue; the traditional view has prevailed to the

extent that grazing management policy in the semi-arid parts of the sub-

continent is essentially founded on the premise that widespread, irreversible

degradation has occurred in post-colonial times. In this paper, we examine this

position in the light of the available published evidence. It is suggested that

some changes in the vegetation of the semi-arid Karoo occurred prior to the

onset of European colonization, a function of phases of climatic aridification

and the impacts of both Kho San hunter-gatherers and Khoi Khoi herders. This

argument contextualizes the alleged historical impacts, which are shown to be

interpreted along the lines of three competing models accounting for the pattern

of assumed vegetation change. The literature concerning Karoo degradation is

reviewed and it is revealed that much of the research throws little light on

which, if any, of the three competing models most closely approximates reality.

Instead, it becomes clear that the recognition of dryland degradation in the

Karoo requires further investigation, and several possible approaches are

presented by which the hypothesis of irreversible change may be tested and the

pattern of vegetation change identified. It is concluded that a more systematic

monitoring programme, including the investigation of vegetation and other

environmental variables, should be instigated in South Africa. [References: 118]

Reprint available from: Dean WRJ UNIV CAPE TOWN PERCY FITZPATRICK INST AFRICAN

ORNITHOL RONDEBOSCH 7700 SOUTH AFRICA NATL BOT INST CLAREMONT 7735 SOUTH AFRICA

UNIV CAPE TOWN DEPT GEOG & ENVIRONM SCI RONDEBOSCH 7700 SOUTH AFRICA.

Ref ID : 233

739. Dean, W.R.J., Hoffman, M.T., and Willis, C.K. The light and the way in

South African desertification research. South African Journal of Science

92(4):170-171, 1996.

Reprint : In File,

Keywords : DESERTIFICATION ASSESSMENT; POLICY

Abstract : UP880-0005 South Africa is a signatory to the United Nations

Convention on Desertification. A recent meeting and workshop in Pretoria

represented the first South African attempt to co-ordinate desertification

research and to target a set of key issues for action. [References: 23] Reprint

available from: Dean WRJ TIERBERG KAROO RES CTR POB 47 PRINCE ALBERT 6930 SOUTH

AFRICA UNIV CAPE TOWN PERCY FITZPATRICK INST AFRICAN ORNITHOL RONDEBOSCH 7700

SOUTH AFRICA NAT BOT INST STRESS ECOL UNIT KIRSTENBOSCH SOUTH AFRICA UNIV VENDA

DEPT BOT VENDA VENDA.

Ref ID : 194

740. Dean, W.R.J. and Macdonald, I.A.W. Historical changes in stocking rates of

domestic livestock as a measure of semi-arid and arid rangeland degradation in

the Cape Province, South Africa. Journal of Arid Environments 26(3):281-298,

1994.

Reprint : In File,

Keywords : STOCKING RATE; DESERTIFICATION ASSESSMENT; NAMA KAROO; KAROO

DESERTIFICATION; VEGETATION CHANGE; ENVIRONMENTAL HISTORY; SAVANNA; SUCCULENT

KAROO; POLICY; ECONOMIC ASPECTS; PRODUCTION POTENTIAL

Abstract : In semi-arid and arid magisterial (administrative) districts (n=45)

in the Cape Province, South Africa, there has been a mean 44-4+/-14.6% (S.D.)

reduction in the stocking rates of domestic livestock over the period 1911-81.

In five savanna districts there has been a mean 36.8+/-8.5% increase in stocking

rate. For all districts during the period 1911-30 the mean stocking rate was

12.5+/-8.6 large stock units/100 ha, and for 1971-81 the mean rate was 8.4+/-7.7

LSU/100 ha (one bovid weighing 420 kg = 1 LSU). The reduction in stocking rate

differs significantly between biomes and shows a general trend towards being

greater in the more arid districts. The reduction is significantly greater in

the succulent Karoo where seven of eight districts have experienced stocking

rate reductions >50%. Districts with a rainfall variability index > 4.0 (i.e.

with the lowest recorded rain only 25% or less of highest recorded rain) show a

significant trend towards larger reductions in stocking rate than do all other

districts. Reductions in stocking rate, however, are not significantly

correlated with the index of rainfall variability or with an index of drought,

suggesting that changes in stocking rate are not influenced only by higher

probabilities of drought. Past and present stocking rates are significantly

correlated with mean annual rainfall in the eastern Karoo, central Karoo,

succulent Karoo and Savanna districts. The total number of stock-water points in

each district in all biomes increased over time. In Gordonia, Kuruman, Mafeking,

Taung and Vryburg, where stocking rates have increased, they are positively

correlated with stock-water points, but in all other districts, this

relationship is negatively correlated.

We conclude that the current livestock stocking rate in the semi-arid and arid

rangelands of the Cape Province is unrelated to market forces or state policy

but is determined by utilizable primary productivity of rangelands. This study

provides evidence that the production potential of drylands has decreased

markedly in semi-arid and arid rangelands throughout the Savanna, Nama-Karoo and

succulent-Karoo biomes of the Cape Province. [References: 60] Reprint available

from: Dean WRJ UNIV CAPE TOWN FITZPATRICK INST RONDEBOSCH 7700 SOUTH AFRICA.

Ref ID : 232

741. Dean, W.R.J., Milton, S.J., and du Plessis, M.A. Where, why, and to what

extent have rangelands in the Karoo, South Africa, desertified. Environmental

Monitoring & Assessment 37(1-3):103-110, 1995.

Reprint : Not in File,

Keywords : DESERTIFICATION ASSESSMENT; AGRICULTURAL EXTENSION; VELD CONDITION;

STOCKING RATE; VELD MANAGEMENT; AGRICULTURAL DEVELOPMENT

Abstract : TP549-0008 We used simple questionnaire surveys to obtain rough

categorical information on the status of semiarid and arid rangelands in the

Karoo, South Africa. We sent questionnaires to extension officers of the

Department of Agricultural Development, asking them to rank the condition of the

rangeland in their extension districts (usually about 500 farms) on a three- or

five-point scale. The questionnaire also sought information on the possible

reasons for changes in the condition of the rangelands; vegetation types most at

risk on mismanaged rangelands; and changes in the status of plants, birds, and

mammals. Extension officers rated 35% of the semiarid rangelands in southwestern

South Africa (the Karoo and southern Kalahari Desert) as being in poor

condition. There was some congruency between the perceived condition of the

agricultural extension district and the percentage that the stocking rate had

decreased. Rangeland condition in more arid areas tends to be poor. Stocking

rates have decreased disproportionately more in arid areas than in the more

mesic areas of southwestern South Africa. Grasses were rated as the most

threatened group of plants, and succulents the least threatened group.

Overgrazing in the past was considered to be the most important cause of

present-day rangeland condition, followed by present overstocking of rangelands.

Antelope were considered more threatened by rangeland management than mammalian

carnivores. Avian raptors and bustards, gamebirds, and tortoises were all

perceived to be threatened by rangeland mismanagement. [References: 28] Reprint

available from: Dean WRJ UNIV CAPE TOWN FITZPATRICK INST RONDEBOSCH 7700 SOUTH

AFRICA.

Ref ID : 1850

742. Dekker, B. Calculating stocking rates for game ranches: substitution ratios

for use in Mopani Veld. African Journal of Range and Forage Science 14(2):62-67,

1997.

Reprint : In File,

Keywords : STOCKING RATE; CARRYING CAPACITY

Abstract : Determation of carrying capacity for mixed- or multi-species grazing

systems is complex. Commonly, each species is compared to the standard large

stock unit (LSU) used in conventional agriculture. However, this approach does

not allow for ecological separation, and thus overlooks the potential for using

the specialised and complementary resource-use habits of wild ungulates to

maximise veld utilisation. The aim of this study was to quantify the overlap in

ungulate resource-use on a game ranch, and to demonstrate how these indices of

overlap can be incorporated into substitution ratios for calculating stocking

rates. Habitat utilisation patterns of Burchell's zebra (Equus burchelli), blue

wildebeest (Connochaetes taurinus), eland (Taurotragus oryx), gemsbok (Oryx

gazella), giraffe (Giraffa camelopardalis), impala (Aepyceros melampus), kudu

(Tragelaphus strepsiceros), and warthog (Phacochoerus aethiopicus), were studied

on the Messina Experimental Farm. Indices of overlap were determined for

spatial distribution, habitat selection, diet composition, and browsing height,

and were calculated as the sum of the percentage points from each resource

dimension that was common to both species. Grazer and browser animal unit

substitution ratios are repesented for each of the ungulates using the index of

combined overlap, metabolic mass and a reference norm of a blue wildebeest

(grazer) and a kudu (browser) respectively. It is proposed that these

substitution ratios can be used to calculate stocking rates for game ranches in

the Mopani Veld.

Ref ID : 1647

743. Dekker, B. Veldbestuur vir ekstensiewe beesvleisproduksie: Die Mara-

stelsel. Grootfontein Newsletter (2):21-25, 1998.

Reprint : In File,

Keywords : VELD MANAGEMENT; LIVESTOCK PRODUCTION; VELD CONDITION; CONSERVATION;

GRASSLAND; PRODUCTION POTENTIAL; GRAZING EFFECTS; FARMING SYSTEMS; CLIMATE;

MONITORING

Notes : This article explores ways in which to enrich natural veld conditions.

It recommends: investigating different grass types and knowing what their

grazing potential is; understanding that all grass types are not necessarily fit

for grazing. Tasty, older grass types must be seen and used as priority

grazing; accept that the best animal production correlates positively with the

existence of sufficient tasty and good natural grazing; plan farms and grazing

camps in accordance with different veld types; remember that cattle eat grass

and that they will only eat leaves when there is a lack of good grass types;

manage the optimal livestock numbers on particular areas of grazing depending on

prevailing veld and climatic conditions. Remember that veld production can vary

up to 300% between seasons; grazing camps must never be allowed to be grazed to

the ground. Up to 60% of its capacity is optimal. The rest must be allowed to

remain for photosynthesis and renewal of plants; it is essential that during the

growing season, veld is permitted to lie fallow in order that reserves can be

built up and so that seedlings can mature and seed production can take place.

Remember, alternate grazing need not necessarily mean resting of veld. A full

season's rest and a resting programme is recommended for sweetveld; keep a

record of the number of livestock and days during which a particular camp is

being used for grazing; and two indications for the farmer that he is

successfully taking veld conservation seriously are where organic material on

the ground surface increases, and where older grass types flourish.

Ref ID : 2472

744. Deliwe, D. The farmer support programme in Chatha Village, Keiskammahoek

District. Development Southern Africa , 1995.

Reprint : Not in File,

Keywords : CISKEI; AID; AGRICULTURAL EXTENSION; ECONOMIC ASPECTS

Notes : The purpose of the study was to investigate the impact of farmer support

programmes in Chatha Village of the Keiskammahoek district. All 26 households,

which joined the FSP were interviewed, as were 24 households which did not join.

A questionnaire survey was administered, interviews were conducted with

officials, FSP-related meetings were attended, and informal observations made

over 3 research periods of a fortnight each between March and November 1991.

Although there have been minor organisational problems, the funding and supply

of inputs seem to be operating fairly smoothly. Mechanisation services were not

effective enough due to under-qualified mechanics. Extension services showed

effective organisation and progress. Marketing was found to be a neglected

area. There has been, among participants, lack of awareness on exactly what FSP

is, and how it works. There has also been a lack of communication between the

farmers, the Department of Agriculture, and the Ciskei Agricultural Bank with

regard to the FSP loans. This article is available at the Document Centre,

Agriculture, University of Fort Hare. See ref. ID no. 2339.

Ref ID : 2514

745. Deliwe, D. The farmer support programme. Occasional Paper no. 35 from ISER,

Rhodes University, Grahamstown.Anonymous Grahamstown:ISER, Rhodes University.

35, 1997.

Reprint : Not in File,

Keywords : CISKEI; AID; ECONOMIC ASPECTS; POLICY; AGRICULTURAL DEVELOPMENT

Notes : The purpose was to investigate and document the impact of a farmer

support programme upon the village of Chatha. Three research periods of a

fortnight each were spent in Chatha between March and November 1991. A

questionnaire was administered to 26 households. Although there are minor

organisational problems the supply and funding of inputs seem to be operating

fairly smoothly. However, in the area of marketing there seems to be no real

progress at all. No efforts were directly channelled towards marketing

arrangements for Chatha farmers. There is also a problem with regard to

official communication, specifically to providing the Farmer Support Programme

(FSP) with a coherent and understandable account of exactly what it is, and how

it works. Linkages between the FSP, the Department of Agriculture and the CAB

are not clear enough in regard to FSP loans. Political instability in Chatha

was also blamed for not achieving the agricultural potential of FSP. This

report is obtainable from the Border Rural Committee, East London. See also ID

ref. no. 2339.

Ref ID : 918

746. Denbow, J.R. Cenchrus ciliaris: An ecological indicator of iron age middens

using aerial photography in eastern Botswana. South African Journal of Science

75:405-409, 1979.

Reprint : In File,

Keywords : SETTLEMENT IMPACTS; GRASSLAND; REMOTE SENSING; BOTSWANA

Abstract : An archaeological reconnaissance in Eastern Botswana has found

Cenchrus ciliaris to be consistently associated with Iron Age middens. Since

dense stands of this grass show up as bare spots on aerial photographs, it has

proved useful in pinpointing the locations of archaelogical sites over a wide

geographical area. Cenchrus was also found to be associated with recently

abandoned Tswana kraals and it is suggested that the presence of this grass on

prehistoric middens indicates a similar use of these sites as animal enclosures.

This hypothesis is supported by the results of archaelogical excavations.

Ref ID : 1674

747. Dennill, G.B. and Donnelly, D. Biological control of Acacia longifolia and

related weed species (Fabaceae) in South Africa. Agriculture Ecosystems &

Environment 37(1-3):115-136, 1991.

Reprint : Not in File,

Keywords : DESERTIFICATION CONTROL; BUSH ENCROACHMENT

Ref ID : 288

748. Denver, D. The pineapple industry: is it an erosion hazard? Dohne Agric

6(1):31-32, 1984.

Reprint : In File,

Keywords : SOIL EROSION; CULTIVATION; EROSION

Notes : The pineapple industry is a relatively young industry, but despite this

it is a highly organised business with many of the producers applying

recommendations which have resulted from intensive research at the Pineapple

Research Station in East London. Added to this is the fact that the industry

itself employs specialists who are forever striving to improve yields, cut

production costs and speed production. From the production point of view

pineapple farming is, to a large extent, succeeding. On the debit side,

however, is the ever present accusation that pineapple farmers are, by their

cultivation practices, causing serious soil erosion, and that this is going

unchecked. The pineapple farmer is, quite often, singled out when erosion comes

up for discussion. This article deals with what has led to this criticism and

whether it is altogether true.

Ref ID : 441

749. Department of Agriculture (Natal Region) Erosion studies using natural

runoff plots. Facet progress report for 09/91. 1991.

Reprint : Not in File,

Keywords : SOIL EROSION; RUNOFF; KWAZULU NATAL

Ref ID : 1929

750. Department of Environmental Affairs Towards sustainable coastal development

in South Africa. Coastal Policy Green Paper. Coastal management policy

programme.Anonymous Cape Town:Department of Environmental Affairs. , 1988.

Reprint : Not in File,

Keywords : POLICY

Ref ID : 2436

751. Department of Water Affairs Management of the Water Resources of the

Republic of South Africa, Pretoria:Department of Water Affairs, 1986.

Reprint : In File,

Keywords : POPULATION; WATER CONSERVATION

Notes : This publication is aimed at increasing awareness of water management

issues so as to promote an effective partnership between water users and the

Department of Water Affairs. In the RSA, the increaseing demand for water

arising from the growth of the population and the economy has to be met from

limited resources that have to be shared by competing user groups and by other

states. Within these limitations, the joint utilization of the available water

and affordable waterworks will best be achieved when the users appreciate the

complexity of water resource development in the RSA.

Ref ID : 40

752. Desert Encroachment Committee Report of Committee.Anonymous Pretoria, South

Africa:Government Printer. , 1951.

Reprint : In File,

Keywords : GOVERNMENT INITIATIVES; KAROO DESERTIFICATION; HYDROMETEOROLOGY;