Bibliography: Land Degradation in South Africa project

figures in order that it may be established whether the degree of change in the

land/population ratio is sufficient to account for declining per capita output,

and the effect that changes in the quality of land may have, both on yields and

upon incentives to cultivate land, is discussed. The main focus of Section 4,

and indeed, the situation which originally led to this study being undertaken,

is an investigation into the reasons why arable land is left uncultivated. A

survey of this matter was conducted, and the responses of landholders as to why

they left part or all of their land idle are grouped according to the factor

shortages which they emphasise, and analysed in detail. In Section 5 the system

of land tenure which prevails in KwaZulu is outlined, together with the way in

which it permits landholders to leave their holdings uncultivated for

comparatively long periods. This is followed by a discussion of the

recommendations of the Select Committee of Land Tenure (KwaZulu, 1976) and of

the degree to which it can be hoped that they will solve the problem of arable

land left uncultivated. Finally, the conclusion tries to offer answers to two

sets of questions, the first being, given the multiplicity of reasons which have

emerged in Sections 3-5 as to why land is not cultivated, those concerning the

nature and extent of the changes which must be brought about if people are to be

made able and willing to cultivate the areas now idle. The second series of

questions will be concerned with the cost to KwaZulu and to SA as a whole of

creating a situation in which all land will be cultivated.

Ref ID : 2212

1281. Letimela, O.N. Denitrification of groundwater for potable

purposes.Anonymous Water Research Commission. 403/1/93, 1993.

Reprint : Not in File,

Ref ID : 1940

1282. Levyns, M. Some observations on the effects of bush fires on the

vegetation of the Cape peninsula. South African Journal of Science 21:346-347,

1924.

Reprint : Not in File,

Keywords : FIRE

Ref ID : 1073

1283. Lewin, R. Paleoclimates in southern Africa. Science 227:1325-1327, 1985.

Reprint : In File,

Keywords : PALAEOENVIRONMENTS; CLIMATE; CLIMATE CHANGE

Notes : This article reports on a workshop held on paleoclimates and evolution,

the second in a series of five, which was held at Sun City in 1995. The overall

aim of the workshops is to see what, if any, patterns of speciation and

extinction are to be discerned in the fossil record during the past 25 million

years and to discover how, if at all, these patterns relate temporarlly to

global and local climate change. Moreover, if there was found to be a

relationship, to decide if it is causal.

Ref ID : 315

1284. Lewis, A.D. Silting of four large resevoirs in South Africa. Communication

(5), 1936.

Reprint : Not in File,

Keywords : SOIL EROSION; SEDIMENTATION

Notes : Second Congress on Large Dams, Washington, 1936.

Ref ID : 1444

1285. Liengme, C.A. A study of wood use for fuel and building in an area of

Gazankulu. Bothalia 14(3&4):245-257, 1983.

Reprint : In File,

Keywords : DEFORESTATION; COMMUNAL AREA; GAZANKULU; ENERGY

Abstract : The utilization of wood for fuel and building timber was studied in a

13 000 ha. area of Gazankulu, near Giyani. Headloads of firewood brought in by

eight of the 978 families present were monitored during six periods in a year.

The two most important sources of firewood are Colophospermum mopane and

Combretum apiculatum. Firewood consumption is estimated at an average of 14,9

kg per family per day. The annual demand for firewood in the whole study area

is, therefore, approximately 5 300 tonnes. Living-huts and storage-huts in the

process of being built were examined. The mean volumes of wood in living-huts

and typical storage-huts are 1.30 m3 and 1.09 m3 respectively. Eighty-nine

living- and 80 storage-huts were built in a year. The demand for finished

timber in the study area in that year was approximately 321 tonnes. Timber use

has not yet outstripped production, but it will do so soon if alternative timber

sources are not provided.

Ref ID : 1443

1286. Liengme, C.A. A survey of ethnobotanical research in southern Africa.

Bothalia 14(3&4):621-629, 1983.

Reprint : In File,

Keywords : SOUTHERN AFRICA; BOTANICAL SURVEY; COMMUNAL AREA; ETHNOBOTANY

Abstract : Existing ethnobotanical information for southern Africa is scattered

through anthropological, medical, botanical and other books and journals, making

the task of getting at the information fairly difficult. The object of this

paper is to provide a unified bibiliography on the subject and to review the

state of knowledge of ethnobotany in southern Africa as reflected in

publications, unpublished manuscripts and museum and herbarium holdings. Those

aspects of ethnobotany most needing attention are identifed. The information is

reviewed on a subject basis.

Ref ID : 694

1287. Liggitt, B. The invasive alien plant Chromolaena odorata, with regard to

its status and control in Natal. Monograph 2. Rural Studies Series.Anonymous

Anonymous Pietermaritzburg:Institute of Natural Resources, University of Natal.

:1-41, 1983. 0-86980-341-7.

Reprint : In File,

Keywords : ALIEN PLANTS; KWAZULU NATAL; FIRE; FOREST; EROSION; EROSION CONTROL;

MONITORING

Notes : Chromolaena odorata is a fast growing and rapidly multiplying shrub,

native to Mexico, the West Indies and tropical South America. It was

accidentifally introduced into SA during the Second World War since when it has

rapidly spread to become one of the commonest shrubs along the coastal belt in

Natal. Although it burns well, owing to the presence of essential oils in the

leaves and stems, C. odorata is well adapted to fire. Adult plants are resistant

to fire, coppicing from the base and seeds germinate well in the ashbed left

after a fire. Highly aggressive and competitive, C. odorata poses a severe

threat to indigenous vegetation. The danger lies in the possiblitiy that this

weed can smother the natural vegetation, kill it and form almost pure stands.

Most detrimental in indigenous vegetation, C. odorata is nevertheless a problem

in commercial forests where it competes with the tree crop, reduces wood volume,

hampers management and poses a fire risk. The weed can also reduce the

productivity of pastures, and although it is not a direct threat to agronomy and

horticulture, it does act as an alternate host to several pests and diseases

which are important to economic crops. Beneficial aspects of this weed have been

identified in various parts of the world. It has been used with considerable

success as a fertilizer and a mulch, and although a fibre has been separated

from the stems, a commercial use has not yet been found for the fibre. Essential

oils have been extracted from the leaves but the peculiar persistant odour and

slightly stinging flavour do not bode well for its commercial use. As a fodder,

C. odorata suffers from the disadvantage that it is relatively unpalatable and

young shoots may contain toxic quantities of nitrate (which is converted to

nitrite in the rumen). Although in severely degraded areas C. odorata may help

in erosion control, its high canopy and difficult eradication are not in its

favour. A survey of the weed in Natal showed it to be distributed all along the

coastal region, in the warmer and moister areas. It appears to be spreading

rapidly and it can be expected to spread into Mozambique and the eastern

Transvaal and possibly into east and central Africa. Research work in many

parts of the world has shown that C. odorata may be killed physically or

chemically without too much difficulty. The problem lies in keeping an area

free from the weed once it has been cleared and this requires frequent follow-up

operations. The hope expressed by many that biological control might be able to

control C. odorata is unlikely to be fulfilled. Biological control agents have

been under investigation since 1966 by the Commonwealth Institute of Biological

Control. Although the introduction of biological control agents should be

attempted in the hope that they will at least slow down the spread of the weed,

physical and chemical methods will remain the most important means of control.

Long-term control may be best achieved by maintaining desirable vegetation in as

healthy and competitive a state as possible, with a good monitoring program to

prevent the weed from re-invading.

Ref ID : 462

1288. Liggitt, B. An investigation into soil erosion in the Mfolozi

catchment.University of Natal, Pietermaritzburg. , 1988. Master of Science.

Reprint : Not in File,

Keywords : SOIL EROSION; KWAZULU NATAL; CONSERVATION; COMMUNAL AREA; POPULATION;

EROSION; SEDIMENTATION; WETLANDS; LAND USE; RUNOFF; CLIMATE; CULTIVATION;

KWAZULU; RAINFALL; RAINFALL EROSIVITY; MAPS

Notes : Soil provides the basis for life on land but with expanding human

populations the pressure on this resource is growing. One of the consequences

of this is accelerated soil erosion. Brown (1986) estimated that the world was

annually losing 25,4 billion tons of soil in excess of new soil formation. Soil

loss on this massive scale, depleting 0,7 percent of the world's cropland per

year, is comparable to mining a depletable resource such as oil. Soil erosion

leads to sedimentation of rivers, dams and estuaries, diminution of wetlands and

water supplies, a decrease in crop yields, lowered agricultural productivity and

it affects land use and vegetative cover. Soil erosion may take place through

the action of wind or water but in the Mfulozi Catchment the effect of water is

the most pronounced. Rainsplash (sheet) erosion is the main erosional process

in the interrill areas but as the runoff is successively concentrated into rills

and gullies the action of running water predominates the detachment and

transport of sediment particles. Streambank erosion and other more specialised

forms of erosion may occur. Factors affecting erosion include climate, soils and

geology, slope cover and management. This study investigated soil erosion in a

525 km2 intensive study area situated around Ulundi and the Mfolozi Catchment.

Soil erosion was assessed from 1:10 000 orthophotos as well as aerial

photographs on a grid-square basis. Data on soil loss factors were also

collected. Results indicated that 12,3 percent of grid squares in the intensive

study area showed severe gully erosion, whereas 33 percent of grid squares

showed evidence of sheet erosion. Soils derived from Dwyka Tillite were

extremely susceptible to erosion with 19,5 percent of grid squares in this

geological type showing significant erosion compared to the erosion resistant

Natal Group soils with only 4,1 percent significantly eroded and the average

level of erosion for the study area being 12,3 percent. Soils derived from Pre-

Cambrian Rocks also showed higher levels of erosion than the average with 13,7

percent significantly eroded. Slope provided some unexpected results with the

flatter areas showing significantly more erosion than the steeper ones. The

critical slope was 16 percent below which erosion was greater than expected, at

a level of 16,1 percent eroded against only 8,2 percent eroded for steeper

slopes. The reason for this is probably due to land use practices. Even a 16

percent slope is steep and it is not recommended in SA to cultivate slopes

steeper than 12 percent. Consequently the flatter areas are used for

cultivation and the steeper areas are used for grazing or not used at all. Land

ownership was found to be extremely significant in affecting erosion, with 15,3

percent of KwaZulu significantly eroded against 6,5 percent for Trust Land and

10,6 for White Natal. Although rainfall erosivity was expected to increase with

increasing erosion, the extremely significant decrease in erosion levels with

900 mm annual rainfall and above indicates the critical importance of cover in

affecting erosion in the study area, and this is borne out by the bioclimate

results. Only 2,0 percent of the land receiving 900 - 1000 mm of rain was

eroded compared with 13,5 percent of land receiving less than this amount. Only

5,7 percent of grid squares in bioclimatic group 2 and 6,1 percent in

bioclimatic group 4 showed significant erosion compared with 18,1 percent for

bioclimatic group 8 but no trends could be detected for bioclimatic groups 9 and

10. For group 9 this is partly due to the low number of data points lying

within this bioclimatic region. Drainage density was also found to have a

highly significant effect on erosion, with classes 2, 3, and 4 (large number of

drainage lines) showing high levels of erosion (20,3, 17,8 and 15,4 percent

respectively) and classes 5 and 6 showing lower levels (9,8 and 3,6 percent

respectively). This is to be expected since gullies themselves form a drainage

network. An important aspect of the research programme was in the production of

soil potential maps. Using easily obtainable data this method enables areas at

greatest risk of erosion to be mapped and remedial action to be taken.

Ref ID : 698

1289. Liggitt, B. An investigation into soil erosion in the Mfolozi catchment.

Final report to the KwaZulu Bureau of Natural Resources. Investigational Report

28.Anonymous Pietermaritzburg:Institute of Natural Resources, University of

Natal. IR 28:i-110, 1988.

Reprint : In File,

Keywords : SOIL EROSION; KWAZULU; COMMUNAL AREA; CONSERVATION

Ref ID : 655

1290. Liggitt, B. and Fincham, R.J. Gully erosion: the neglected dimension in

soil erosion research. South African Journal of Science 85(1):18-20, 1989.

Reprint : In File,

Keywords : SOIL EROSION; EROSION; CLIMATE

Notes : The authors conclude that this investigation has shown that several

natural factors affect the degree of gullying. They may set the potential of an

area to erode, and the extent to which that potential is realised depends on the

management of the land. From an understanding of the influence of these factors

on erosion, it is possible to evaluate them as a basis for determining the

erosion hazard of an area. The results of this study confirm the importance of

geological type on soil erosion, despite the overriding influence of climate and

vegetation on soil formation which has led to similar soil types being

distributed over diverse geological formations. This indicates that the South

african binomial system of soil classification is probably a poor basis for

determining soil erodibility.

Ref ID : 1387

1291. Lindeque, L. A detailed case study of resource degradation/desertification

in the Reitz Magisterial District.Anonymous National Department of Agriculture.

:1-49, 1998.

Reprint : In File,

Keywords : LAND DEGRADATION; FREE STATE; ENVIRONMENTAL HISTORY; DROUGHT; FLOODS;

GRASSLAND; RAINFALL; EROSION; RUNOFF; LAND USE; CONSERVATION; SOIL EROSION;

STATISTICS; VELD CONDITION; SUBSIDIES; SOIL CONSERVATION

Notes : The author concludes that Reitz's undulating landscape, sandy soils in

especially the Ca6 land type and high intensity thunderstorms lead to the

relative erodibility of the resource. Periodic droughts and floods further

contribute to large-scale resource degradation. The vegetation in the district

consists of grassland, sour veld progression in the Ca land types and mixed veld

in the Ea. land types. As a result of the relatively high mean annual rainfall,

the basal cover of the district is of such a nature that it adequately protects

it against soil losses. Only a few cases of serious erosion occur, and it is

mainly the result of overgrazing and injudicious water runoff control planning.

The excerpt from Acocks, 1953, already mentions fallow lands as a result of

excessive soil losses as well as the occurrence of karoid type vegetation as a

result of overgrazing. As the census data indicate, changes in land use over

the past ten years, benefited conservation. Large areas of marginal land were

withdrawn and reclaimed by planting a perennial grass, mainly Eragrostis

curvula. During the comparison of aerial photographs, the positive effect of

integrating farm planning on the conservation status of the district was also

clearly visible. On reading the conservation history of the district, it is

evident that the unplanned subdivision of farms and a lack of judicious farming

methods, resulted in overgrazing and soil erosion. Natural disasters such as

droughts and floods have been part of farming since time began and the course of

history caused considerable damage to natural resources. Although initially,

development in the agricultural industry was slow, the industry experienced a

boom after 1910, despite the fact that frequent droughts and floods occurred.

From the production statistics it is evident that the use of more scientific and

judicious methods contributed to Reitz having a well-established and thriving

agricultural industry. The local co-operative (VKB) and organised agriculture

played an integral part in this process. The condition of the veld in Reitz is

good. The mean veld condition for the district is 63,08. The presence of

declared weeds, especially spear thistle and large cocklebur (burweed) is posing

a serious threat to the natural veld. Concomitant herewith, is the change in

species composition of palatable to less palatable species, a problem posing a

threat to the general condition of the veld. Injudicious grazing practices, but

mainly, overgrazing and incorrect burning methods, are the main culprits.

Considerable inputs by the department's soil technicians and subsidy system

contributed to the good condition of the soil resource. A large number of soil

conservation works have been erected in the district since 1952, and especially

during the period 1977 up to and including 1987, hundreds of kilometres of

contours and waterways were erected. A source of concern is the maintenance of

soil conservation works. As a result of poor maintenance, many of the

conservation works are losing their efficacy, thus resulting in excessive soil

losses. In general, the farmers in the district have a high level of awareness

of conservation and fully realise the nature, extent and consequences of

resource degradation. Resource conservation has become a norm in the district.

Low profit margins currently seriously threaten the conservation condition of

the district. Farmers simply do not have the capital to erect conservation

works, nor to maintain them. This is the most important reason for their

peception that resource conservation should be a shared responsibility between

the land user and the state. Although the land user primarily is responsible

for resource conservation, the state should also play a major role, especially

in regard to the provision of funds and expertise. One of the initial

objectives of this study was to test the data obtained at national workshops by

means of detailed studies of certain districts. On the completion of this

study, is it evident that the information obtained at the consultative workshops

corresponds very well with the data contained in this document? The conclusion

arrived at, is that the data supplied by officers at the national workshops are

a very good reflection of the actual position.

Ref ID : 2160

1292. Lindley, A.J., Bosch, J.M., and Van Wyk, D.B. Changes in water yield after

fire in fynbos catchments. Water SA 14:7-12, 1988.

Reprint : Not in File,

Keywords : FIRE; FYNBOS

Ref ID : 1711

1293. Liniger, L. and Van Lyden, G. WOCAT : A framework for the evaluation fo

soil and water conservation: Questionnaire on the SWC Map (Revised

edition).Anonymous Bern:Lang Druck AG. , 1998.

Reprint : In File,

Keywords : WATER CONSERVATION; CONSERVATION; MAPS; DESERTIFICATION ASSESSMENT;

GLOBAL CHANGE

Notes : This document sets out explaining what WOCAT (the World Overview of

Conservation Approaches and Technologies) is, what it does and how it operates.

It goes on to describe SWC (soil and water conservation) in the context of

WOCAT. It provides a framework for the evaluation of SWC, a user's guide

(including explanations and a questionnaire) and annexures (including categories

of SWC technologies and addtional information).

Ref ID : 599

1294. Lipton, M. and De Klerk, M. Land, labour and livelihoods in rural South

Africa, Durban:Indicator Press, 1996.pp. 1-452.

Reprint : In File,

Keywords : LAND REFORM; SOCIOECONOMIC ASPECTS; POVERTY; LABOUR; WESTERN CAPE;

KWAZULU NATAL; NORTHERN PROVINCE

Notes : Can small-scale farming, which has proved labour intensive and efficient

in many other labour surplus countries, generate sustainable livelihoods in SA,

with its inheritance of large capital-intensive farms? Given the balance of

interests and power, and the capacity of the South African state, is rural

reform a feasible political option? Will the rural reforms of SA's new

government - on land redistribution; labour and tenancy reform; liberalisation

of the regulatory system for agriculture - improve the lives of the rural poor,

or will they, as some warn, have unintended and adverse effects? These are some

of the questions examined by leading agricultural economists and social

scientists in their reserach for the 'Rural Livelihoods' Project. The project

generated much new work - and some sharply contrasting views. The findings

published in these two volumes cover regional case-studies of the Western Cape,

KwaZulu-Natal and Northern Province. They are essential reading for those

concerned with rural reform and with finding solutions to the problems of high

unemployment and poverty that continue to haunt post-apartheid SA.

Ref ID : 722

1295. Little, A.M. The impact of tourism on the environment and the culture of

the local population. Paper presented at the Strategic Workshop for Transkei

Tourism, Port St Johns, 17-18 January. Occasional Paper 69.Anonymous Anonymous

Scottsville:Institute of Natural Resources. , 1991.