Bibliography: Land Degradation in South Africa project

record 2 000 observations in each of a range of sample sites. A random number

generator was used to select 30 sets of samples of size N (number of point-

observations) from each sample site. A measure of similarity for each sample

with every other in a set was calculated to establish the variation that may be

expected for that sample size. The Richards function was used to determine the

sample size (number of point-observations) required to retrieve a miminum level

of precision. It is proposed that 100 point-observations are sufficient for

coarse management scale investigations, 200 for monitoring programmes and 300

for detailed scientific studies.

Ref ID : 197

1041. Hare, H.L. Remarks on changed conditions in the Karroo in recent years.

The Ostrich :20-25, 1937.

Reprint : In File,

Keywords : KAROO DESERTIFICATION; HYDROMETEOROLOGY; VEGETATION CHANGE; DROUGHT

Notes : The writer concludes that he is glad that a few Korhaans, the Blue

(Eupodotis caerulescens), White-quilled (Afrotis afroides) and Vaal

(Heterotetrax vigorsii) are still present in the Karoo, but that they show no

signs of increasing in number. In his opinion, it all boils down to the fact

that big changes have unquestionably taken place in vegetal covering of the

country during the last 15 years, partly as a result of droughts, but mainly as

a direct result of overgrazing. Good sheep feed has disappeared to a certain

extent and its place has been taken by useless plants, notably "bitterbos" and

grass is more in evidence after good rains than formerly. Grass has its uses,

certainly, but from a sheep farmer's point of view it is a poor substitute for

good Karoo-bush.

Ref ID : 398

1042. Hare, P.D., du Plessis, S., Cress, W.A., and Van Staden, J. Stress-induced

changes in plant gene expression: prospects for enhancing agricultural

productivity in South Africa. South African Journal of Science 92:431-440, 1996.

Reprint : Not in File,

Keywords : PRODUCTION POTENTIAL; SOUTHERN AFRICA; DROUGHT; SUSTAINABLE

DEVELOPMENT

Abstract : The natural environment of southern Africa is characterised by great

climatic diversity and marked inter-seasonal variability in climatic conditions.

It is estimated that less than 20% of SA by area yields mean annual primary

agricultural outputs in excess of 40% of its potential. Environmental stress is

the primary cause of the difference between observed and potential agricultural

yields. It also accounts for considerable inter-annual variability in yield and

thereby poses a threat to food security. Drought, in particular, has played a

dominant role historically in limiting agricultural growth. Since the adverse

influence of abiotic stress on agricultural output leads to an almost continous

drain on state finances, the development of stress-tolerant varieties of

agriculturally important crops is likely to be of great economic importance.

Although plant responses to environmental stress involve adaptation at several

levels of organisation, they all must ultimately have a genetic basis. Several

genes are now known to respond to different stresses commonly encountered in

agriculture. The genetic manipulation of these genes holds considerable promise

as a first step towards increasing environmental tolerance and is well within

the scope of plant biotechnology currently at our disposal. This review

attempts to assess the feasibility of using such an approach as part of a long-

term sustainable development strategy in southern Africa and to indicate

strategies that might be considered to enhance stress tolerance of crops of

agricultural importance. In the light of increasing evidence implicating the

existence of a stress response system in plants, it is proposed that

overlapping responses to different environmental stresses may be mediated by

common cellular signal transduction pathways. Recent studies of signalling

cascades in higher plants have identified ion channels, intracellular signalling

proteins, and second messengers as critical components mediating early events in

signal transduction. In the long term, targeting the genes encoding components

of stress-related signal transduction pathways might be more profitable than

manipulation of genes involved in intermediary metabolism. Transgenic crops

altered as a result of stress-related cellular signalling may display increased

ability to adapt to several stresses experienced concurrently in the field.

Since the molecular details of stress-related signal transduction in plants

remain largely unknown, however, characterisation of the molecular signals

involved in stress perceptions and the molecular events that specify the

expression of stress tolerance will be necessary to provide a sound basis on

which such strategies can be founded.

Ref ID : 1136

1043. Hargreaves, S. The land reform pilot programme: capturing opportunities

for rural women, 1919.

Reprint : Not in File,

Keywords : LAND REFORM; GENDER ASPECTS; LAND TENURE

Ref ID : 851

1044. Harmse, J.T. Human destruction of pans on the east Rand. Proceedings of

the 27th IGU conference, Washington, D.C.Anonymous Anonymous :241, 1992.

Reprint : Not in File,

Keywords : SETTLEMENT IMPACTS; HYDROLOGY

Ref ID : 2018

1045. Harper, J.L. Population biology of plants, London:Academic Press, 1977.

Reprint : Not in File,

Keywords : POPULATION

Ref ID : 1706

1046. Harris, J. Our shrinking land. Conserva 6(4):6-22, 1991.

Reprint : In File,

Keywords : DEFORESTATION; DESERTIFICATION ASSESSMENT; DESERTIFICATION CONTROL;

ECONOMIC ASPECTS

Notes : The author describes what "desertification" is and thus brings the word

and the concept close to home, SA. He shows that deforestation is a first step

in the process of desertification. He then speaks of the possibilities of

reversing or halting desertification, but warns that there are no quick

solutions. The planting of trees and indigenous growth are valuable tactics to

employ in arresting desertification. A further necessary device to use is

effective marketing and education or conscientising of ordinary citizens.

Ref ID : 147

1047. Harrison, Y.A. Herbaceous recovery of communal grasslands after the

removal of high continuous grazing pressure.University of the Witwatersrand.

:iii-46, 1993. A fenceline contrast study was conducted in various sweetveld and

sourveld communal grasslands and adjacent areas with varying periods of

exclusion of communal grazing to determine the rate and extent of change of a

number of vegetation and soil variables following the reomoval of high and

continuous grazing pressure. Grass species composition similarity indices showed

a significant exponential decrease with increasing time since protection from

continous grazing (TSP) in both veldtypes. A change in grass species composition

occurred within four to nine years of protection from communal grazing in

sweetveld, and in six to nine years in sourveld. In both veldtypes palatability

increased with TSP, while the increaser/decreaser categories showed no

relationship with TSP. In sweetveld the abundance of perennials showed a

significant increase with TSP, while the abundance of annuals showed a

concomitant decrease. No relationships were evident in sourveld. Grass species

diversity, basal cover, and density showed no relationship with TSP in

sweetveld, but a general increase with TSP was found in sourveld. Soil bulk

density, field capacity, pH and soil nutrients showed no evidence of a

relationship with TSP in both veldtypes, while soil porosity increased

significantly with TSP in sweetveld, but not in sourveld. In general, these

findings suggest that the removal of the high level of grazing pressure has

allowed for the rapid improvement in the grass sward which is more

characteristic of a good veld condition.Master of Science.

Reprint : In File,

Keywords : COMMUNAL AREA; DESERTIFICATION ASSESSMENT; GRASSLAND; VELD CONDITION;

VELD MANAGEMENT; SOIL NUTRIENTS

Ref ID : 2337

1048. Harrison, Y.A. and Shackelton, C.M. Resilience of South African communal

grazing lands after the removal of high grazing pressure. Land Degradation

Development 10:225-239, 1999.

Reprint : In File,

Keywords : GRASSLAND; SOIL NUTRIENTS; VEGETATION CHANGE; VEGETATION DYNAMICS;

BIODIVERSITY; COMMUNAL AREA

Abstract : A paired site study was conducted of communally grazed eutrophic and

dystrophic grasslands and adjacent ungrazed areas of varying periods of

exclusion from communal grazing. This allowed determination of the rate and

extent of change of a number of vegetation and soil variables following the

removal of high and continuous grazing pressure characteristic of communal

lands. Similarity indices for grass species composition between the grazed and

adjacent ungrazed areas showed a significant exponential decrease with

increasing time since protection from continuous grazing. Most change in grass

species composition occurred within four to nine years of protection from

communal grazing in eutrophic grasslands, and in six to nine years in dystrophic

grasslands. In both grassland types palatability increased with time since

protection In eutrophic sites the abundance of perennials showed a significant

increase with time since protection, while the abundance of annuals showed a

concomitant decrease. This relationship was not evident in dystrophic

grasslands. Grass species diversity, basal cover and density showed no

relationship with time since protection in the eutrophic sites, but a general

increase with time since protection was found in dystrophic sites. Soil bulk

density, field capacity, pH and soil nutrients showed no evidence of a

relationship with time since protection for either grassland type, while soil

porosity increased significantly with time since protection at eutrophic sites,

but not dystrophic sites. These relatively rapid changes following the removal

of the high grazing pressure indicate that these systems are characterized by

relatively high resilience.

Ref ID : 600

1049. Harsch, E. Apartheid's great land theft: the struggle for the right to

farm in South Africa, New York:Pathfinder Press, 1986.pp. 1-50.

Reprint : In File,

Keywords : LAND REFORM; ENVIRONMENTAL HISTORY; POLITICAL ASPECTS; POLICY

Notes : Most people outside SA, including opponents of the apartheid system have

little or no access to accurate information about the reality of SA society, its

class structure and social relations. This lack of information is particularly

gaping with regard to the struggle for equal land rights. This pamphlet aims to

help fill this gap. It is based on two articles that appeared in the December

16 and 30, 1985 issues of Intercontinental Press. By telling the story of the

forced dispossession of Africans of the soil and the struggle against this

massive land theft, the pamphlet also explains a great deal about the origins of

the apartheid system, its current policies, and the revolutionary movement to

overthrow it.

Ref ID : 913

1050. Hartwig, G.L.F. South African forestry surges forward. Address to the 4th

Annual General Meeting of the S.A. Institute of Forestry at Sabie on 8th June

1972. South African Forestry Journal (83):1-3, 1972.

Reprint : In File,

Keywords : FORESTRY

Notes : In response to the Minister of Forestry's declaration that the area of

softwood timber plantations in the Republic of SA will have to be extended 3,2

times if it is to meet the country's anticipated softwood timber requirements at

the end of the 20th century, the writer poses some questions, which he

investigates. The first is, has the country so much land suitable for

afforestation available? If so, further steps may need to be taken anyway, as

demand is likely to increase even more. The salient feature of this document is

the enormous increase in demand for softwood pulpwood and the quite substantial,

though much less spectacular increase in demand for hardwood mining and timber

and pulpwood.

Ref ID : 529

1051. Harvett, C.M. Inter-relationships of poverty and environmental degradation

in South African black communities.University of Natal, Pietermaritzburg. ,

1994. The inter-relationships of poverty and environmental degradation in South

African Black communities is analysed. A literature review investigates the

definition, measurement and nature of poverty. It also identifies environmental

degradataion within these communities. Many of these communities are found to

be characterised by high levels of poverty and environmental deterioration.

International experience reveals a strong relationship between the impoverished

and environmental quality. A downward spiral of poverty and environmental

degradation is identified with various elements that aggravate this cycle. A

case study analysis using participatory research techniques, conducted in the

Mpumelelo settlement near Pietermaritzburg, investigated these relationships. A

questionnaire survey using a systematic sampling technique, captured demographic

features, socio-economic characteristics, local resource utilisation,

prioritisation of "needs" as well as the local peoples' perceptions and

attitudes regarding the environment. Levels of environmental degradation at the

settlement are determined by comparative observation and objective assessment.

Interviews with organisations actively involved with the community were also

conducted. Both the literature review and the case study analysis give evidence

of a downward spiral of poverty and environmental degradation in many Black

South African communities; with high population growth rate, inequitable

distribution of land, lack of resources, rapid urbanisation, lack of tenure,

conservation conflicts and inappropriate development and administative policy,

fuelling this crisis. Socio-economic and political change, participatory and

bottom-up planning and development that focuses on the poor are required, in

order to reverse this process and achieve sustainable development.Master of

Science.

Reprint : In File,

Keywords : SOCIOECONOMIC ASPECTS; LAND DEGRADATION; POVERTY; COMMUNAL AREA;

POPULATION; CONSERVATION; POLICY

Ref ID : 583

1052. Harwin, G.O. and Theron, E.P. Research on radical veld improvement,

Pretoria:Department of Agriculture, 1975.

Reprint : Not in File,

Keywords : VELD MANAGEMENT; DESERTIFICATION CONTROL

Ref ID : 1233

1053. Haschick, S.L. and Kerley, G.I.H. Boergoats- a threat to indigenous

herbivores and vegetation in valley bushveld areas. Grassland Society :49-51,

1996.

Reprint : In File,

Keywords : AGRICULTURAL DEVELOPMENT; LAND USE; MODELS

Notes : The distribution of bushbuck (Tragelaphus scriptus) and boergoats (Capra

hircus) have overlapped considerably in Valley Bushveld areas since the

introduction of the domestic boergoat. Boergoat pastoralism is now one of the

primary forms of land-use in the Valley Bushveld areas, and as goats are largely

browsers, this farming practice revolves around the natural browse provided by

the trees and shrubs of these regions. Valley Bushveld vegetation is, however,

sensitive to utilization and is rapidly being eliminated under these current

pastoral practices. The densely structured Valley Bushveld vegetation provides

a suitable habitat for bushbuck and they are one of the few indigenous large

herbivore species still found free ranging in large numbers in Valley Bushveld

areas. Competition can be defined as the use of a resource by an individual or

species in such a way, that it reduces the availability of that resource for

other individuals or species. It is generally accepted that greater probability

of competition exists between species that have a similar ecological status.

Bushbuck and boergoats co-occupy a similar habitat and despite the fact that the

social systems of these species differ considerably, they are both browsers of

similar body size and may therefore be competing in terms of available forage.

Potential for competition is further enhanced by the fact that only a small

percentage of the above-ground plant biomass is available to the browser in

Valley Bushveld areas. Stable communities are by definition the end products of

a process whereby competition is minimised, and one should therefore rarely

encounter competition among members of an established community. Goats are a

recently introduced domestic species, the likelihood of competition, or the

probability of interference, between bushbuck and boergoats is, therefore, high

as they have not co-evolved in Valley Bushveld areas. The article goes on to

give an assesssment of potential competition (including forage intake rates, and

the effect of spinescence on foraging abilities); and foraging heights. The

article concludes by saying that combined boergoat and bushbuck pastoralism

appears non-sustainable within Valley Bushveld, as boergoats appear to have the

capacity to competitively exclude bushbuck. In addition to their apparent

natural competitive advantage over bushbuck, goats have an obvious advantage due

to the fact that they are domestic animals. Besides being provided with water

and shelter, contact with natural enemies, such as predators, parasites and

disease, are minimized through human interaction. Control is even exerted over

their foraging areas and seasonal shortages of food are alleviated through the

supply of supplementary fodder. Bushbuck are generally solitary animals, as

opposed to the high degree of gregariousness associated with boergoat herds.

Thus, goats foraging in a given area would have a far greater impact on the

vegetation than bushbuck and would effectively be able to overutilise their own

preferred plants species, and thus those of the bushbuck as well. Boergoat

pastoralism on Valley Bushveld vegetation does also not appear to be sustainable

as boergoats are capable of overcoming the physical defenses of some of these

plants. In Valley Bushveld areas, where these species co-occur, careful

consideration should therefore be given to the stocking rates of boergoats, in

order to ensure that they do not become a threat to indigenous herbivores and

the vegetation itself. Research into herbivore-herbivore and herbivore-plant

interactions are urgently needed in order to develop models of sustainable

utilization of Valley Bushveld.

Ref ID : 852

1054. Haschke, S.W. Human constraints in stock reduction and communal land

management.Anonymous Cedara:Department of Agriculture. N/A/95/22, 1995.

Reprint : Not in File,

Keywords : SOCIOECONOMIC ASPECTS; CARRYING CAPACITY; COMMUNAL AREA; LAND TENURE

Ref ID : 684

1055. Hatch, G.P. The bioeconomic implications of various stocking strategies in

the semi-arid savanna of Natal.University of Natal, Pietermaritzburg. , 1994.

Climatic and market uncertainty present major challenges to livestock producers

and arid and semi-arid environments. Range managers require detailed

information on biological and economic components of the system in order to

formulate stocking strategies which maximise short-term financial risk and

minimise long-term ecological risk. Computer-based simulation models may provide

useful tools to assist in this decision process. This thesis outlines the

development of a bioeconomic stocking model for the semi-arid savanna of Natal.

Grazing trials were established at two sites (Llanwarne and Dordrecht) on

Llanwarne Estates in the Magudu area of the semi-arid savanna or Lowveld of

Natal. The Lowveld comprises a herbaceous layer dominated by Themeda triandra,

Panicum maximum and O. coloratum and a woody layer characterised by Acacia

species. The sites differed initially in range composition. Llanwarne was

dominated by Themeda triandra, Panicum maximum and O. coloratum, while Dordrecht

with a history of heavy stocking was dominated by Urochloa mosambicensis,

Sporobolus nitens and S.iocladus. Three treatments were stocked with Brahman-

cross cattle at each site to initially represent 'light'(0.17 LSU ha-1),

'intermediate' (0.23 LSU ha-1) and 'heavy' (0.30 LSU ha-1) stocking. Data

collected at three-week intervals over seven seasons (November 1986 to June 1993

or 120 measuring periods) provided the basis for the development of a

bioeconomic stocking model (LOWBEEF - LOWveld BioEconomic Efficiency

Forecasting) which comprised two biological sub-models (GRASS and BEEF), based

on step-wise multiple linear regression models, and an integrated economic

component (ECON). The GRASS model predicted the amount of residual herbage at

the end of summer (kg ha-1) and the forage deficit period (days) over which

forage supplementation would be required to maintain animal mass. Residual

herbage mass at the end of summer (kg ha-1) was significantly related (P < 0.01)

to cumulative summer grazing days (LSU gd ha-1), rainfall (mm) (measured 1 July

to 30 June) and range condition (indexed as the sum of the proportions of T.

triandra, P. maximum and P. coloratum). The forage deficit period (days) over

which herbage mass declined below a grazing cut-off of 1695 kg ha-1 was

significantly related (P < 0.01) to residual herbage mass at the end of summer.

The BEEF model predicted the livemass gain over the summer (kg ha-1) which was

significantly related (P < 0.01) to rainfall (mm) and stocking rate (LSU ha-1),

but interestingly not to range condition. The economic component (ECON)

reflected the difference between gross income (R ha-1) and total costs, which

were based on fixed and variable cost structures (using 1993 Rands), including

demand-related winter feed costs, to reflect net returns to land and management

(R ha-1). A conceptual model of range dynamics, based on three discrete states,

was developed to summarise the effects of rainfall and stocking rate in the

semi-arid savanna. State 1, characterised by S. iocladus and S. nitens, was

associated with heavy stocking. Movement towards State 2, characterised by T.

triandra and O. maximum, was associated with periods of above-average rainfall.