Bibliography: Land Degradation in South Africa project

seldom. Even the monthly average calculated of 13 determinations during 13

months, equals in a good season, that of bushes, 0.3 to 0.47 per cent., but the

minimum values of grasses like Eragrostis conferta, Digitaria eriantha

stolonifera are much lower than the minimum values of the bushes. Any adverse

condition, like drought or frost, affect the grasses to a much higher extent

than the bushes. Their phosphorus content decreases much quicker than that of

the bushes. In the less favourable season, 1930-31, a number of grasses died

down completely, others came up only after the January or April rains, 1931;

some, however, survived the drought quite well, but their growth was very

limited (Rhodes grass). Thus, even when the percentual phosphorus content was

high, the absolute amount of phosphorus was small. Resuming, it may be said

that, in such karroid areas as the Southern Free State, stress should be laid on

the recuperation of barren veld by indigenous bushes which are, from the point

of view of minerals, a very good food for sheep. Some grasses like Rhodes

grass, which is easily propagated and can withstand a severe drought, although

its growth is very limited, should certainly be tried as cattle food and if kept

low, as sheep food in summer. Other grasses, like Paspulum dilatatum, Dactylia

glomerata, Eragrostis conferta, are hopeless failures during a dry season and

are not worth while propagating.

Ref ID : 516

1082. Heron, G. and Cloete, L. Household survival strategies in Shikini,

Transkei.Anonymous Pretoria:Human Sciences Research Council. ASS/BBS-24, 1991.

Reprint : Not in File,

Keywords : SOCIOECONOMIC ASPECTS; TRANSKEI

Ref ID : 2417

1083. Heron, G.S. The household economic differentiation and agricultural

production in Shixini, Transkei. Development Southern Africa 8(1), 1991.

Reprint : Not in File,

Keywords : AGRICULTURAL PRODUCTION; TRANSKEI; LIVESTOCK PRODUCTION; STATISTICS;

RURAL DEVELOPMENT

Notes : The purpose of the study was to determine the household differentiation

and agricultural production in Shixini, Transkei. Fieldwork was conducted in

Nompha, a sub-ward of the administrative area, between January 1988 and March

1989. Two household surveys were taken. A general socio-economic survey was

applied to all 676 households in Shixini. This was followed by an agricultural

survey of 23 out of the 67 households in Nompha sub-ward. The survey considered

both crop and livestock production activities. The study revealed that the

household's access to stock is the most important variable in determining maize

yields. Draught cattle, in particular, give households access to a ready source

of fertilizer to membership of ploughing companies. The study emphasises the

importance of stock keeping as a variable in understanding agricultural

production and economic differentiation. The author also made a remark in that

development interventions in the peripheral areas (e.g. Transkei) of South

Africa should take a holistic view of the situation in which people live.

Issues such as improving inequality of life of people in these areas are of

vital importance, but development researchers should not lose sight of micro-

issues such as the household and importance of stock in agricultural production.

This article is available at the Document Centre, Agriculture, University of

Fort Hare. See ref. I.D. no: 2339.

Ref ID : 2440

1084. Hewitson, B.C. Deriving regional precipitation scenarios from general

circulation models.Anonymous Cape Town:Department of Environmental and

Geographical Science. 751/1/99, 1999.

Reprint : In File,

Keywords : MODELS; CLIMATE; CLIMATE CHANGE; DROUGHT; METHODOLOGIES; GLOBAL

CHANGE

Notes : Regional climate change poses an important threat to the already

variable and drought flood-prone climates of South Africa. Current scenarios of

potential change are severely limited in spatial and temporal resolution,

especially with regard to precipitation, and are in critical need of

alternatives in order to plan for the future. Downscaling is one widely

recognized methodological approach for dealing with GCM inadequacies in

developing regional scale climate change scenarios, and is considered the most

viable for the South African context. Multiple approaches to downscaling are

available, although many have significant infrastructural constraints or

problematic assumptions which underlie their procedures. The approach adopted

in this work has thus focused on the empirical downscaling option, and the

variant of empirical solutions has been to directly relate atomospheric forcing

to local climate through the application of ANNs. This represents further

development of earlier methodological work undertaken for the WRC. An early

formal evaluation of the initial methodology against 3 other downscaling

approaches has shown that the ANN approach is able to capture important aspects

of regional climates not managed by other techniques. Problems identified in

the comparative study have also greatly assisted in refining the new work

undertaken here. Of all empirical downscaling techniques, the ANN approach is

arguably the method with the least problematic assumptions, and provides a

tractable procedure for developing regional scenarios from long term GCM

simulations, and for use with multiple GCM data sets. Validation of the ANN

techniques has shown the procedure to be viable and effective in capturing the

primary forcing over a wide range of climate regimes and seasonal variation.

Using geopotential height fields representing circulation dynamics, and

atmospheric humidity as an indicator of precipitable water, the ANN procedure is

able to effectively capture the spatial and seasonal attributes of precipitation

over South Africa. It is in recognizing the important role played by

atmospheric humidy that the methodology has been further refined in comparison

to work carried out by other research groups. Atmospheric humidity has been

shown to be a critical variable in terms of the local climate response to global

change. In particular the inclusion or exclusion of humidity in the procedure

can influence the results to such an extent that over certain regions the sign

of the climate change may alter, as well as the magnitude. Consequently it is

argued that downscaling without cognizance of the role of atmospheric humidity

leads to scenarios that only represent climate response to circulation dynamics,

which, while informative, may be substantially different from actual climate

response. Similarly, as much of the potential climate within different

components of the physical system may be sensitive to the daily temporal

characteristics of climate, it is importnat that the downscaled climate

reasonably reflects daily variance. Since the downscaling cannot include local

forcing factors, and since these are largely insensitive to the global climate

change signal the methodology incorporates this source of variance through

stochastic modeling. The addition of this source of variance substantially

improves the daily characteristics of the downscaled climates and allows

scenarios to be constructed in terms of the daily behaviour of the downscaled

climates. The remaining errors in the downscaled climate are manifest primarily

as a tendency toward nominally wetter than observed conditions. However, in the

context of GCM skill, and given the level of accuracy and alternative sources of

climate change scenarios, the downscaled procedure and subsequent climate

projections represent a viable, justifiable, and pragmatic solution for the

immediate and near future climate change impact research needs.

Ref ID : 401

1085. Heydenrych, B. Circles in the landscape: The Flora Conservation Committee

of the Botanical Society looks at centre-pivot irrigation. Veld & Flora

79(4):108-110, 1993.

Reprint : In File,

Keywords : CULTIVATION; POLLUTION; IRRIGATION; CONSERVATION; FAUNA

Notes : The author concludes in his article that it would appear that centre-

pivot irrigation is not very environmentally friendly. The law should be

amended to ensure the conservation of not only soil, but flora, fauna and water

as well.

Ref ID : 2221

1086. Heydorn, A. Estuaries and the open sea. In: Oceans of life off southern

Africa, edited by Payne, A. and Crawford, R.Cape Town:Vlaeberg Publishers, 1989,

Reprint : Not in File,

Keywords : SOUTHERN AFRICA

Ref ID : 305

1087. Hiemstra, L.A.V. Die status van navorsing op sedimentvervoer/The status of

research on sedimentation, Verhand. S. Afr. Inst. siv. Ingrs. 1966.

Reprint : Not in File,

Keywords : SOIL EROSION; SEDIMENTATION

Ref ID : 306

1088. Hiemstra, L.A.V. and Edwards, P.J. Minimisation of soil loss in land-use

planning. 1966.

Reprint : Not in File,

Keywords : SOIL EROSION; AGRICULTURAL DEVELOPMENT; LAND USE

Notes : Unpublished report, Dept. A.T.S., Natal Region.

Ref ID : 2027

1089. Higgins, S.I. and Richardson, D.M. Predicting plant migration rates in a

changing world: the role of long-distance dispersal. American Naturalist , 1999.

Reprint : Not in File,

Notes : This article is still in press at this time.

Ref ID : 2028

1090. Higgins, S.I., Turpie, J.K., Constanza, R., Cowling, R.M., Le Maitre,

D.C., Marais, C., and Midgley, G.F. An ecological economic simulation model of

mountain fynbos ecosystems. Dynamics, valuation and management. Ecological

Economics 22:155-169, 1997.

Reprint : Not in File,

Keywords : MODELS; FYNBOS

Ref ID : 2231

1091. Hill Kaplan Scott Transkei soil conservation programme : reconnaissance

survey report.Anonymous Umtata:Transkei Government Department of Agriculture and

Forestry. , 1985.

Reprint : In File,

Keywords : TRANSKEI; SOIL CONSERVATION; CONSERVATION; FORESTRY; SOIL EROSION;

EROSION

Notes : The authors were commissioned by the Department of Agriculture and

Forestry to undetake a survey of the soil erosion status of the Transkei. The

task was to identify the nature and extent of the soil erosion problem

throughout the Transkei and prepare accurate information for a priority listing

of areas affected by soil erosion. The areas identified were: a. Xalanga; b.

Cacadu; c. Umtata; d. Tsolo; e. Nqamakwe.

Ref ID : 198

1092. Hilton-Taylor, C. Karoo-Namib Regional Centre of Endemism: CPD Site AF51.

Western Cape Domain (Succulent Karoo), Republic of South Africa and Namibia. In:

Centres of Plant Diversity. A guide and strategy for their conservation.

Volume 1: Europe, Africa, South West Asia and the Middle East, edited by Davis,

S.D., Heywood, V.H., and Hamilton, A.C.Cambridge:WWF & IUCN, 1994,p. 204-217.

Reprint : In File,

Keywords : SUCCULENT KAROO; VEGETATION CHANGE; KAROO DESERTIFICATION; NAMIBIA;

EROSION; ALIEN PLANTS; CONSERVATION

Notes : This article documents the location as the Western Cape Domain (southern

Namibia and western parts of the Cape Province, SA), occurring to the north and

inland of the Cape Floristic Region; between latitudes 26o00 - 32o 00'S and

south-west of a line drawn between Luderitz (15oE) and Port Elizabeth (26oE).

The area comprises 111,212 km2. The altitude is 0-1907 m (mostly below 800 m).

Vegetation consists of low to dwarf succulent shrubland, dominated by stem and

leaf succulents and fine-leaved evergreen shrubs. The flora, c. 5000 vascular

plant species; 35% endemic. c.900 on the Red Data List. Extremely rich in

succulent species, particularly in the families Aizoaceae sensu lato,

Asclepiadaceae, Crassulaceae and Euphorbiaceae. This high succulent diversity

is unparalleled worldwide. There are many endemic geophytic and annual taxa.

Useful plants occurring are many ornamental plants, particularly bulbs and

succulents, medicinal plants, and edible plants. Other values include: the

annual spring flower displays have great tourist potential. The area has

historically been used for pastoralism. Viticulture and grain production occur

in the southern, wetter ares. The region is rich in mineral resources. Threats

include overgrazing and poor land management practices which have led to severe

soil erosion, loss of biological diversity and desertification. Other threats

are mining operations, ploughing of marginal lands, succulent collectors, alien

plant invasions and urban development. Conservation: <2% conserved. Urgent

conservation action is required. Centres of plant diversity of greatest

importance are: the Gariep Centre (Richtersveld), Kamiesberg, Western Mountain

Karoo (Nieuwouldtville to Sutherland), Vanrhynsdorp Centre (Knersvlakte) and

Little Karoo..

Ref ID : 2250

1093. Hilton-Taylor, C. Protea odorata, a case of benign neglect. Plant Talk

7:24-25, 1996.

Reprint : Not in File,

Ref ID : 2251

1094. Hilton-Taylor, C. Red data list of southern African plants. Strelitzia

4.Anonymous Anonymous Pretoria:National Botanical Institute. , 1996.

Reprint : Not in File,

Ref ID : 2252

1095. Hilton-Taylor, C. Red data list of southern African plants. 2. Corrections

and additions. Bothalia 27:195-209, 1997.

Reprint : Not in File,

Ref ID : 930

1096. Hilton-Taylor, C. and Le Roux, A. Conservation status of the fynbos and

karoo biomes. In: Biotic diversity in southern Africa: concept and conservation,

edited by Huntley, B.J.Cape Town:Oxford University Press, 1989,p. 202-223.

Reprint : Not in File,

Keywords : CONSERVATION; ALIEN PLANTS; FYNBOS; NAMA KAROO; SUCCULENT KAROO;

BIODIVERSITY; GRAZING EFFECTS; STATISTICS

Ref ID : 226

1097. Hilton-Taylor, C. and Moll, E.J. The Karoo - a neglected biome. Veld &

Flora 72(2):33-36, 1986.

Reprint : In File,

Keywords : NAMA KAROO; SUCCULENT KAROO; CONSERVATION; KAROO DESERTIFICATION;

FARMING SYSTEMS

Notes : The authors conclude that the central problem in the Karoo is selective

grazing. Reduced stock numbers only provide a partial solution. One answer may

lie in the incorporation of wild ungulates into the farming system. What is

certain is that a better understanding of the basic ecological processes in the

Karoo is vital.

Ref ID : 2518

1098. Hirst, M.M. The utilisation of Catha Edulis in the household economy of a

Xhosa farm inhabitants of the Polo Reserve, Eastern Cape. Journal of

Contemporary African Studies , 1997.

Reprint : Not in File,

Keywords : EASTERN CAPE; AGRICULTURAL PRODUCTION; CISKEI

Notes : The purpose of the research was to document the utilisation of Catha

Edulis in the household economy of Xhosa farm inhabitants of the Polo reserve,

Eastern Cape Province, of South Africa. An oral historical method based on

recall from extensive conversation with legitimate and progressive leaders in

the community. Not all Xhosa farm inhabitants residing in the relative

proximity of the growing sites chew Catha Edulis stems and leaves. However, some

of them were found to chew it. The plant was found to be utilized by some Xhosa

speaking people residing afield at emGwali and the townships of Stutterheim.

This article can be found in the main library, University of Fort Hare. See also

ID ref. no. 2339.

Ref ID : 2029

1099. Hobbs, R.J. The nature and effects of disturbance relative to invasions.

In: Biological invasions. A global perspective, edited by Drake, J.A., Mooney,

H.A., Di Castri, F., Groves, R.H., Kruger, F.J., Rejmanek, M., and Williamson,

M.Chichester, UK:John Wiley & Sons, 1988,p. 389-406.

Reprint : Not in File,

Ref ID : 2030

1100. Hobbs, R.J. and Huenneke, L.F. Disturbance, diversity and invasion:

implications for conservation. Conservation Biology 6:324-337, 1992.

Reprint : Not in File,

Keywords : CONSERVATION

Ref ID : 1045

1101. Hobson, F.O. and Baarnhoorn, A.S.J. Exploring the potential of the

descending-point method to measure utilization in Karoo veld. Journal of the

Grassland Society of southern Africa 5(2):102-107, 1988.

Reprint : In File,

Keywords : VELD CONDITION; KAROO DESERTIFICATION; VELD MANAGEMENT

Abstract : The descending-point method of vegetation survey proved effective in

measuring meaningful plant cover changes during a grazing period. No

significant changes in basal cover or plant height were detected. Changes in

canopy spread and canopy cover could only be used to detect changes in

utilization at levels lighter than 50% and 70% respectively. Selective

utilization between species implies that it may be extremely difficult to

achieve a specified level of utilization in practice. Therefore, in karoo veld,

resting may be considered a more practicable veld management strategy than

attempts to achieve a specific utilization intensity. The descending-point

method is time-consuming in determining canopy cover. Thus, methods based on

more effective point sampling, within the canopy spread, may be more appropriate

for this purpose.

Ref ID : 1492

1102. Hobson, S. Deterioration of the veld. Agricultural Journal of the Cape of

Good Hope 9:491-492, 1896.

Reprint : Not in File,

Keywords : RAINFALL; VELD MANAGEMENT; DESERTIFICATION CONTROL; LAND DEGRADATION;

SUBSIDIES; PLANT-ANIMAL INTERACTIONS; ENERGY; IRRIGATION; STOCKING RATE

Notes : The failure or wearing out of the veld has been noticed by observant

citizens for some years past and plans had been suggested for staying it.

Undoubtedly, it was felt that fencing and paddocking would be the best remedies,

but unfortunately, attacks by pests and depradations by jackals had very much

neutralized the full value of these remedies. As a result, alternative remedies

were read out to a meeting of the Graaff-Reinet Farmers' Association by the

author. Included in his suggestions are: vermin removal (to be subsidised by

the government); spreading cattle dung over grazing veld to increase the supply

of 'Leitjies Ganna', a valuable saline plant for stock; layering; sparing of

Spekboom veld until rainfall season; growing Mimosa and Karee-doorn trees for

shelter, food and fire-wood; laying of thorn branches over sluits; turning out

sluits and water-courses, wherever practicable with a dam-scraper; and

preventing overstocking. Some discussion regarding these suggestions. followed.

Ref ID : 2304

1103. Hodgson, F.D.I., Kirchner, J.O.G., Lukas, E., and Fourie, G. Enhancement

of the national groundwater data base facilities.Anonymous Pretoria:Water

Research Commission. , 1993.

Reprint : In File,

Keywords : MAPS

Notes : This study spanned three years of research and development and the main

benefits deriving from this work, can be summarised as follows: 1. the NGDB

facilities on the mainframe computer have been supplemented by the creation of

an equivalent data base system which runs on IBM compatible personal computers;

2. a link has been provided between the NGDB and HydroCom, so that data may be

extracted from the NGDB and used within HydroCom; 3. data may also be entered

directly into HydroCom, and later be uploaded to the NGDB, under supervision of

the NGDB manager; 4. all data processing and creation of displays, such as

graphs and maps, are performed within the HydroCom package and not within the

NGDB. The latter is merely a data storage facility; 5. apart from ground-water

data, HydroCom also allows entry and processing of hydrological meteorogical and

hydrochemical data; 6. many individuals within the private and public sectors,

have contributed ideas for the enhancement of the data base during the past

three years. These suggestions have all been incorporated within the HydroCom

package. 7. active promotion of the use of the HydroCom package, in conjunction

with the NGDB, has been an ongoing feature of this project. Brochures have been

printed and distributed, demonstrations given at conferences and private tuition

given in the use of the software; and 8. the HydroCom package is presently being

used in more than 80 ground-water projects throughout SA, by the Directorate of

Geohydrology, mining companies, other industries and ground-water consultants.

Ref ID : 2031

1104. Hoffman, J.H. and Moran, V.C. The invasive weed Sesbania punicea in South

Africa and prospects for its biological control. South African Journal of

Science 84:740-742, 1988.

Reprint : Not in File,

Ref ID : 1676

1105. Hoffman, J.H. and Moran, V.C. Biological control of Sesbania punicea

(Fabaceae) in South Africa. Agriculture Ecosystems & Environment 37(1-3):157-

174, 1991.

Reprint : Not in File,

Keywords : DESERTIFICATION CONTROL; BUSH ENCROACHMENT

Ref ID : 1667

1106. Hoffman, J.R. Introduction: Biological control of weeds in South Africa.

Agriculture Ecosystems & Environment 37(1-3):1-4, 1991.

Reprint : Not in File,

Keywords : BUSH ENCROACHMENT; DESERTIFICATION CONTROL

Ref ID : 987

1107. Hoffman, M.T. The rationale for karoo grazing systems: criticisms and

research implications. South African Journal of Science 84:556-559, 1988.

Reprint : In File,

Keywords : VELD MANAGEMENT; NAMA KAROO; GRAZING EFFECTS; MODELS

Notes : The Karoo Biome Project aims to develop a predictive understanding of

karoo ecosystem functioning as a basis for sound management. The project may be

redundant, however, as existing management programmes claim to exhaust all

options for the Karoo These programmes invoke succession theory as a model for

understanding karoo dynamics and largely ignore the unpredictable nature of the

karoo environments. Current options exist mostly within an untested or

untestable theoretical framework. The rationale for each management programme

is outlined and the lack of supporting evidence discussed. Some implications

for project researchers are briefly mentioned.

Ref ID : 1747

1108. Hoffman, M.T. Vegetation studies and the impact of grazing in the semi-

arid Eastern Cape.University of Cape Town. , 1989. This thesis, consisting of

two reviews and five research papers, has two principal objectives. Firstly, it

is a synthesis of literature concerned with the rationale of karoo grazing