Bibliography: Land Degradation in South Africa project

planning policies whether traditional or betterment. It is the conclusion of

this study that betterment cannot be considered an effective vehicle for the

prevention of soil erosion as the factors which cause this phenomena are to be

found at a national and not a regional level.

Ref ID : 420

2167. Whitfield, A.K. and Paterson, A.W. Flood-associated mass mortalities of

fishes in the Sundays estuary. Water SA 21(4):385, 1995.

Reprint : In File,

Keywords : FLOODS

Abstract : Mass mortalities of fishes in South African estuaries have been

linked to changes in salinity, temperature and dissolved oxygen concentratons.

This short communication documents two fish kills which were associated with

high suspensoid levels during flash floods in January 1995. A total of 16 fish

species, belonging to freshwater, estuarine and marine taxa, were recorded dying

in the Sundays Estuary. Both juvenile and adult fish appeared to be affected by

the high levels of silt and clay carried by the flood waters. Although the

available evidence suggests that clogging of the fish gill filaments by

suspended sediments was primarily responsible for the mass mortalities on 16

January 1995, osmoregularoty and other stress factors (eg. reduced dissolved

oxygen levels associated with the flood waters) may also have contributed to the

fish kills.

Ref ID : 386

2168. Whitmore, J.S. The effect of conservation farming on runoff from a semi-

arid catchment. 2nd SCA Meeting of Specialists on Hydrology, 1959.Anonymous

Department of Water Affairs. Technical Report 23, 1959.

Reprint : Not in File,

Keywords : SOIL EROSION; SOIL CONSERVATION; RUNOFF; SUSTAINABLE AGRICULTURE

Ref ID : 510

2169. Whitmore, J.S. The effect of conservation farming practices on runoff from

a semi-arid catchment.Anonymous Pretoria:Department of Water Affairs. Technical

Report 5, 1959.

Reprint : Not in File,

Keywords : SOIL EROSION; FARMING SYSTEMS; LAND USE; RUNOFF; CULTIVATION

Ref ID : 2107

2170. Wicht, C.L. Report of the Committee on the Preservation of the Vegetation

of the South Western Cape (Special publication).Anonymous Cape Town:Royal

Society of South Africa. , 1945.

Reprint : Not in File,

Keywords : WESTERN CAPE

Ref ID : 254

2171. Wiegand, T. and Milton, S.J. Vegetation change in semiarid communities -

simulating probabilities and time scales. Vegetatio 125(2):169-183, 1996.

Reprint : In File,

Keywords : MODELS; VEGETATION CHANGE; VEGETATION DYNAMICS; VELD CONDITION;

GRAZING EFFECTS; SUCCULENT KAROO

Abstract : VP213-0005 In arid regions, the effects of grazing or sparing

management on natural communities of long-lived plants generally take decades to

become evident. Event-driven dynamic behavior, unpredictable and low rainfall

and complicated interactions between species make it difficult to assess

probabilities and time scales of vegetation change. To gain a better

understanding of the main processes and mechanisms involved in vegetation

change, we have developed a spatially explicit individual based model that

simulates changes in plant communities over long time spans. The model, based on

life-history attributes of the five dominant component plant species of a

typical Karoo shrub community, follows the fate of each individual plant within

the community, the sum of which is community dynamics, The model explores the

differential effects of a realistic range of rainfall pattern on the abilities

of these species to compete, survive, grow and reproduce. The specific aim of

the model is to identify key processes of vegetation change and to calculate

probabilities and timespans for transitions between different vegetation states.

Such knowledge is needed for species conservation and sustained animal

production. We show that the time-scale for changes of the dynamic state of the

system are long compared with human lifespans. Employing the full range of

possible rainfall scenarios showed that short-term community dynamics (years to

decades) and species composition depend strongly on the short- term (years)

sequence of rainfall events. In all simulation experiments the final vegetation

state varied by more than 37% after a 60 year simulation period. Simulating

resting of an overgrazed part of the shrub community indicated that little

improvement in rangland condition was likely during a period of 60 years. Even

such active management, as (simulated) clearing of unpalatable shrubs? resulted

in only a 66% probability that degraded shrubland would be in good condition

after 60 years resting. Simulated overgrazing of a rangeland in good initial

condition only became obvious 40 or 50 years after the initiation of heavy

grazing, and after 70 years the mean vegetation state eventually reached that of

an overgrazed rangeland. [References: 62] Reprint available from: Wiegand T UFZ

ENVIRONM RES CTR DEPT ECOL MODELLING PERMOSERSTR 15 D-04318 LEIPZIG GERMANY UNIV

CAPE TOWN FITZPATRICK INST ZA-7700 RONDEBOSCH SOUTH AFRICA.

Ref ID : 251

2172. Wiegand, T., Milton, S.J., and Wissel, C. A simulation model for a shrub

ecosystem in the semiarid Karoo, South Africa. Ecology 76(7):2205-2221, 1995.

Reprint : In File,

Keywords : MODELS; VEGETATION DYNAMICS; SUCCULENT KAROO

Abstract : Plant community dynamics in semiarid regions appear to be "event-

driven." The aim of our model is to attain an understanding of the main

processes determining the spatial and temporal dynamics of a shrub community in

the semiarid Karoo on a large temporal scale and to identify the significant

events that drive this shrub community.

Vegetation at the study site covers 15-20% of the soil surface and is dominated

by five shrubs: Brownanthus ciliatus (Mesembryanthemoideae), Ruschia spinosa

(Ruschioideae), Galenia fruticosa (Aizoaceae), Pteronia pallens (Asteraceae),

and Osteospermum sinuatum (Asteraceae). Grasses and annuals play little part in

the dynamics of this vegetation.

The model is based on detailed life history data for the five dominant species

and on monthly long-term rainfall data for this region. The method of "dynamic

automata" is employed to model individual plants. Growth, death, seed

production, gemination, and seedling establishment are modelled over long time

scales in annual time steps under the influence of the stochastic and

unpredictable rainfall in ungrazed rangeland. In the absence of grazing,

survival of seedlings depends on their competitive ability during the seedling

stage and their ability to compete with established plants in neighboring cells.

The model shows that the dynamics of this shrub community are typified by

episodic and discontinuous changes in species composition with intervening

quasistable phases lasting some decades. The reason for this episodic behavior

is that both recruitment and mortality of plants depend on particular

conditions. Using 93 complete data sets with monthly rainfall data taken at the

weather station in Prince Albert we show that rainfall is only sufficient for

seedling recruitment in 44% of all years for B. ciliatus and in <30% of all

years for the four other species. We identify two types of abrupt and

discontuinuous changes in species composition: (1) big recruitment events that

can only occur if plant density is low and if rainfall conditions are

extraordinarily favorable and (2) big mortality events that can only occur if

cohorts, originating from big recruitment events, die within a short period of

time and if little further recruitment has taken place.

However, this behavior is not a property of the biota but is generated by

rainfall input to the model. By using a different rainfall input, the model can

also display regular cyclic succession. Therefore there appeared to be no

contradiction between sudden, discontinuous changes and gradual, continuous and

reversible changes in vegetatiion composition.

Ref ID : 103

2173. Wilcocks, J.R.N. Desert encroachment in South Africa.University of the

Witwatersrand. :iii-349, 1977. The literature on desert encroachment in South

Africa is reviewed from six main standpoints. Climate, vegetation, ecological

balance, fauna, hydrology and agriculture form the basis of the discussions.

Climatologically, the assertion of diminution of rainfall is considered and

rejected in favour of fluctuating trends in precipitation. These variable

climatic conditions are related to the alteration of plant successions and it is

found that bush encroachment results. The modification of vegetation and

consequently the ecology of habitat by drought and by overgrazing is discussed.

In the same way the deterioration of faunal habitat is evaluated. Also of

importance in a consideration of environmental equilibriums is the hydrology of

arid and semi-arid regions, these aspects are discussed briefly. The various

agricultural implications of desertification in South Africa are integrated with

the foregoing discussions in an attempt to assess the major causes of the

problem. Accompanying the literature review is a bibliography which comprises

570 annotated entries.Master of Arts.

Reprint : In File,

Keywords : CLIMATE; BUSH ENCROACHMENT; KAROO DESERTIFICATION; DROUGHT; GRAZING

EFFECTS; FAUNA; PRODUCTION POTENTIAL

Ref ID : 387

2174. Wilde, J. A basic appreciation of runoff control. Dohne Agric 9(1):9-13,

1987.

Reprint : Not in File,

Keywords : SOIL EROSION; EROSION CONTROL; RUNOFF; EROSION

Notes : The author notes that the world is filled with evidence that man is,

without a doubt, doing a very thorough and speedy job of destroying the earth.

In the author's opinion, the average farmer is apparently uncaring about the

damages he causes. Top soil is irretrievably lost through water erosion.

Fertilizer and nutrients are lost at huge cost. If we are to survive, we are

warned that we have to reduce massive losses to at least that of the natural

rate of soil formation. The only way to achieve this, is through the use of

dynamic, co-ordinated system of anti-erosion measures where mechanical and

biological methods are used in various combinations depending on the specific

situation. A major component of any co-ordinated system is a proper run-off

plan, and example of which is detailed in this document.

Ref ID : 1910

2175. Williams, A., Eberhard, A.A., and Dickson, B. Synthesis Report of the

Biomass Initiative.Anonymous Pretoria:Department of Mineral & Energy Affairs.

PFL-SYN-01, 1996.

Reprint : In File,

Keywords : ENERGY

Notes : The Biomass Initiative (BI) was conceptualised as a part of a broader,

integrated energy provision strategy aimed at resolving the rapidly

deteriorating energy supply situation in many of South Africa's rural areas.

The central goal of the strategy is to secure the provision, through a balanced

least-cost mix, of adequate, affordable and convenient energy sources to satisfy

rural energy needs. The BI programme was designed in two stages, the Planning

and Implementation Phases. This report is a synthesis of the work carried out

under the Planning Phase, and it consisted of a number of different elements,

namely: research; biomass resource and demand assessment; fuelwood production;

infrastructure; fuelwood demand side management; and dissemination and

education.

Ref ID : 1132

2176. Williams, G. Land-ing in trouble. Indicator South Africa 24(4):29-34,

1995.

Reprint : In File,

Keywords : LAND REFORM; POLICY; LABOUR

Notes : Land reform is expected - or feared - to realise a number of different

purposes which are reflected in different policies and legislative enactments

which may well, in a variety of cases, come into conflict with one another.

These purposes include: (1) the redistribution of land to the landless poor and

women who have been denied access to land and a decent living conditions, and to

the 'historically disadvantaged', who may or may not be the same sort of people;

(2) promoting the emergency of commercial farmers previously denied

opportunities to farm; (3) the restitution of land to individuals and

communities who were dispossessed; and (4) securing tenure rights for labour

tenants, farm workers and others with claims to occupy or use land. The

possible results of attempting to practically implement these objectives are

discussed.

Ref ID : 2470

2177. Williams, J.L.H. The role of women in agricultural development and its

implications for extension: experiences at the Keiskammahoek Irrigation Scheme,

Ciskei. South African Journal of Agricultural Extension 23, 1994.

Reprint : Not in File,

Keywords : AGRICULTURAL DEVELOPMENT; IRRIGATION; CISKEI; AGRICULTURAL EXTENSION;

GENDER ASPECTS

Notes : The purpose of the study was to investigate the role of the wives of the

men involved in the Keiskammahoek Irrigation Scheme (KKIS). The information

concerning the women at the KKIS was collected during 1991 by means of a

questionnaire survey. At the time of the survey there were 26 male-headed

families on the scheme, and all the 26 women were interviewed. The study found

that women were very busy, and apart from their household duties, played an

important role on the farm by tending to the vegetable gardens as they were in

watching the cattle, while the men were often absent from the farm. The author

stressed that farmers' wives should be included in the extension programmes.

Extension staff should contact the husband and wife jointly, paying the

necessary respect to the husband, but ensuring that the wife is involved and

fully understands the advice and encouragement which is given. For this to

happen, the training of more female extension staff is essential. This article

is available at the Document Centre, Agriculture, University of Fort Hare. See

ID ref. no. 2339.

Ref ID : 2377

2178. Williams, W. Household vegetable production in a rural community in Alice,

Ciskei. 1988.

Reprint : Not in File,

Keywords : CISKEI; METHODOLOGIES; AGRICULTURAL PRODUCTION; CULTIVATION

Notes : The aim of the study was to investigate vegetable production in home-

gardens in the Alice area as well as the role that the use of "imifino" plays.

The methodology used for the study was a survey questionnaire with responses

generated by an interview process amongst the households involved in vegetable

production. The findings revealed that it is usually the 'agriculturally

active' homsestead that have vegetable gardens, whereas 'non-agricultural'

homesteads tend to have fewer vegetable gardens. The main reason for not having

gardens is that they have to be fenced. The most popular vegetables selected

for growing in home-gardens (in order of preference) are cabbage, potatoes,

spinach, beetroot, carrots, onions and tomatoes. Except for spinach, beetroot

and carrots, the above order is also reflected in the buying of vegetables. In

conclusion, the study indicates that the home-garden plays an important role in

providing the family with these vegetables. In vegetable supplies for home use,

the considerable demand for fresh vegetables in the Alice region suggests that

the small-scale vegetable grower has the opportunity to satisfy this demand.

This thesis is obtainable from the Document Centre, Agriculture (UFH). See ref.

I.D. no: 2339.

Ref ID : 2398

2179. Williams, W. and Rose, C.J. Mgwalana socio-economic survey.Anonymous ,

1989.

Reprint : Not in File,

Keywords : AID; CISKEI; RURAL DEVELOPMENT; GENDER ASPECTS; AGRICULTURAL

PRODUCTION; LABOUR; SOCIOECONOMIC ASPECTS

Notes : The purpose of the study was to provide baseline and felt needs

information as an aid to future planning. A sample of 20% of rural households

was surveyed by questionnaire. The average age of household heads was 60 years

of whom 45% exceeded 65 years. 37% were female. Household incomes were almost

entirely (98%) agricultural. Other sources of household income were as follows:

pensions (70%), remittances (17%) and wages (21%) contributing to 78 (62.5%)

households. In addition 49 heads and 27 wives received income from employment.

The average income of 120 households was R273 per month. Domestic expenditure

averaged R170 per month of which R122 was spent on food. Animal products

contributed to household health and nutrition. For example, one-half of owners

milked cows for the house. Crop sales were negligible, but 20% households

shared crops with those in need. This report is available from the Document

Centre, Agriculture, UFH. See ref. I.D. no: 2339.

Ref ID : 2396

2180. Williams, W. and Ward, H.K. Socio-economic of the Khambashe tribal

authority area, Ciskei.Anonymous ARDRI:University of Fort Hare. , 1989.

Reprint : Not in File,

Keywords : CISKEI; AID; LIVESTOCK PRODUCTION; PRODUCTION POTENTIAL; RURAL

DEVELOPMENT; SOCIOECONOMIC ASPECTS; ECONOMIC ASPECTS; LABOUR; AGRICULTURAL

DEVELOPMENT; GENDER ASPECTS

Notes : The purpose of the study was to provide baseline and felt needs

information relating to the district and its inhabitants as an aid to future

planning. An approximate 5% sample of households were surveyed within each

village (there are 6 tribal villages with an estimated 646 households). The

main subjects addressed included human aspects, employment, incomes,

expenditure, land, crops, livestock, problems and potential for agriculture,

together with the perceptions and needs of individuals and the community. The

average age of household heads was 61 years. Thirty-eight percent were female.

Household heads were barely literate. The average family size was 8.3 persons;

the household income was almost entirely (97%) non-agricultural with pensions,

remittances and wages as dominant sources of income. The average income was

R296 per month. Domestic expenditure averaged R173 per month, of which R114 was

usually spent on food (43% of the income). Agricultural earnings were very low.

Animal products contributed to household health and nutrition, and crop sales

were negligible. The general felt-needs picture is for households to enjoy

domestic standards and rural infrastructure comparable to those in peri-urban

communities. The authors generally felt that the district is suitable for

staple food, crop and livestock production. This report is obtainable from

ARDRI, University of Fort Hare. See ref. I.D. No: 2339.

Ref ID : 2397

2181. Williams, W. and Ward, H.K. Socio-economic survey of Mgwalana Tribal

Authority area, Ciskei.Anonymous University of Fort Hare:ARDRI. , 1989.

Reprint : Not in File,

Keywords : CISKEI; AID; LIVESTOCK PRODUCTION; SOCIOECONOMIC ASPECTS;

AGRICULTURAL DEVELOPMENT; PRODUCTION POTENTIAL; STATISTICS; RURAL DEVELOPMENT;

LABOUR; ECONOMIC ASPECTS; AGRICULTURAL PRODUCTION; GENDER ASPECTS

Notes : The purpose of the study was to provide baseline and felt needs

information relating to the district and its inhabitants, and aid to future

planning. A 20% sample of rural households (N=125) was surveyed by

questionnaire. The main subjects addressed included human aspects, employment,

income, expendisture, land, crops, livestock, problems and potential for

agriculture, together with the perceptions and needs of individuals and the

community. The study found that the average age of household heads was 60

years. Thirty seven percent were female. Sixty percent of the household heads

had 6 or more hears of schooling; the average family size was 7.6 persons.

Household income was almost entirely (98%) non-agricultural with pensions,

remittances and wages as the dominant source. The average income was R2 773 per

month; domestic expenditure averaged R1 770 per month of which R122 was usually

spent on food (43%) of income). Agricultural earnings were very low, <2% of

cash income. Animal products contributed to household health and nutrition.

Crop sales were negligible. The general felt-needs picture was for households

to enjoy domestic standards and a rural infrastructure comparable to those in

peri-urban communities. The author indicated that Mgwalana is better suited to

livestock production than to rainfed crop production. Thus, much greater

attention has to be given to income generating possiblities from animal

production than has hitherto been the case. This report is obtainable from

ARDRI, University of Fort Hare. See ref. I.D. no: 2339.

Ref ID : 2195

2182. Williams, W.D., Noble, R.G., Best, H.J., Forster, S., Herold, C.E.,

Moolman, H., and Schlettwein, C.H.C. Salinization. Hart, R.C. and Allanson, B.R.

Pretoria:Council for Scientific and Industrial Research. 93:86-107, 1988.

Reprint : Not in File,

Keywords : SALINIZATION

Notes : South African National Scientific Programmes Report no. 93.

Ref ID : 1058

2183. Willis, M.J. and Trollope, W.S.W. Use of key grass species for assessing

veld condition in the eastern Cape. Journal of the Grassland Society of southern

Africa 4(3):113, 1987.

Reprint : Not in File,

Keywords : VELD CONDITION; EASTERN CAPE

Notes : Only copied p.113.

Abstract : The current technique used in the Eastern Cape for assessing veld

condition and trend assumes that the operator is able to identify all the grass

species in the sample site. This is a serious limitation to its use by extension

officers, consultants and farmers. Data from the Dohne Sourveld and the False

Thornveld of the Eastern Cape were used successfully to identify the minimum

number of key grass species required to assess the condition and trend of the

veld.

Ref ID : 1488

2184. Wilson Water supply in the basin of the Orange River or Gariep, South

Africa. Royal Geographical Society 35:106-112, 1865.

Reprint : Not in File,

Keywords : EASTERN CAPE; HYDROLOGY

Ref ID : 2196

2185. Wilson, A. Managing mountain veld for water. Veld & Flora :35-38, 1984.

Reprint : Not in File,

Ref ID : 143

2186. Wilson, F. A land out of balance. In: Restoring the land. Environment and

change in post-apartheid South Africa. edited by Ramphele, M. and McDowell,