Bibliography: Land Degradation in South Africa project

detected with field-based methods of data collection, and that there is close

correspondence between ground data and indices of vegetation cover obtained from

contemporary Landsat Multispectral Scanner satellite data. Field data

representing aerial cover of the herbage and woody species layers were collected

along transects radiating away from water at two sites grazed by cattle in

central Australia. Graphical representation of the litter and herbage

components demonstrate that gradients of decreasing cover attibutable to

increasing grazing pressure occur along all, or sections, of each transect.

Highly significant correlations exist between the field data and satellite

indices of vegetation cover. Localised shrub increase and patches of recent

erosion obscured trends of increasing cover with distance from water on parts of

some transects. Soil surface state (describing past erosion) was a significant

covariate of cover change at one site. Our ability to characterise gradients of

increasing vegetation cover with distance from water using both field and

satellite data should mean that the grazing gradient method, when used with

satellite data, is a suitable technique for assessing the extent of landscape

recover following good rainfall.

Ref ID : 1630

383. Batanouny, K.H. Human impact on desert vegetation. In: Man's impact on

vegetation, edited by Holzner, W., Werger, M.J.A., and Ikusima, I.The

Hague:Dr.W.Junk Publishers, 1983,p. 139-149.

Reprint : In File,

Keywords : POPULATION; DESERTIFICATION ASSESSMENT; PLANT-ANIMAL INTERACTIONS;

VEGETATION CHANGE

Notes : In addition to the well-known fact that desert vegetation is

continuously exposed to the full impact of extreme and drastic environmental

conditions, it is important to assess man's position as a most legitimate

ecological factor. Since his advent into the biosphere, man has been playing a

considerable role in changing the vegetal environment. Both good and bad results

are obvious. Due to the continuous increase of the population in the arid and

semi-arid regions far-reaching changes are observed in their plant life. In view

of the precarious balance among the components of the desert ecosystem the human

impact results in dramatic changes in the vegetation. These changes are due to

the direct impact of man on the vegetation or his impact on the physical

environment which inevitably affects the vegetation. As a consequence of the

fragility of the desert ecosystem the changes are often irreversible. In this

article the salient features of the desert vegetation pertinent to the mechanism

of its changes and the aspects of human impact are given.

Ref ID : 1632

384. Batjes, N.H. Global assessment of land vulnerability to water erosion on a

half degree by half degree grid. Land Degradation & Development 7:353-365, 1996.

Reprint : In File,

Keywords : EROSION; METHODOLOGIES; CLIMATE; RAINFALL; LAND USE; MODELS; MAPS;

BIODIVERSITY; WATER CONSERVATION; GLOBAL CHANGE; SOIL CONSERVATION; SOIL

EROSION; LAND DEGRADATION

Abstract : A simple methodology is presented for assessing the risk of water

erosion at the global level. It uses a half degree latitude by a half degree

longitude soil database, developed at ISRIC, and auxiliary databases on climate

and land cover with similar spatial resolution. Area estimates are presented

for (1) susceptible areas, as determined by rainfall erosivity, topography and

soil erodibility, and (2) vulnerable areas as further determined by the pressure

of current land use. Model output for vulnerability is evaluated against

observed data on severity of soil degradation by water as presented on the map

of human-induced soil degradation (GLASOD). Cross-tabulation of the

vulnerability and GLASOD subsets gave a significant Cramer's correlation

coefficient of 0.72 (P<< 0.005). Thus a fair geographic agreement was observed

between the grid cells considered vulnerable to water erosion, under current

conditions of land cover, and regions in which water erosion occurs currently.

The qualitative model can serve to raise awareness on issues of soil degradation

by water at the global level by identifying regions at risk, where more detailed

studies are needed. However, it does not provide any information on the actual

rate of erosion at the field scale, nor on the associated decrease in crop

productivity and biodiversity. The study of productivity changes associated

with water erosion, at different scales, is currently an important topic on

ISRIC's research agenda.

Ref ID : 1633

385. Bawa, K.S. and Menon, S. Biodiversity monitoring: the missing ingredients.

Tree 12:12, 1997.

Reprint : In File,

Keywords : BIODIVERSITY; MONITORING; CONSERVATION; POLICY; GOVERNMENT

INITIATIVES

Notes : With mounting losses in biological diversity, inventorying and

monitoring of biodiversity to assess the magnitude and rate of losses are

emerging as dominant themes in conservation biology. It is argued that rushed

inventories will compromise scientific rigour and have little influence on

decision making. Losses in biological diversity are so severe that inventorying

and monitoring must be accorded a high priority and can have a major impact on

policy-making and public opinion.

Ref ID : 999

386. Baxter, A.J. and Meadows, M.E. Palynological evidence for the impact of

colonial settlement within lowland fynbos: a high-resolution study from the

Verlorenvlei, southwestern Cape Province, South Africa. Historical Biology 9:61-

70, 1994.

Reprint : In File,

Keywords : PALAEOENVIRONMENTS; FYNBOS; SETTLEMENT IMPACTS; CULTIVATION; WESTERN

CAPE; VEGETATION CHANGE; ARCHAEOLOGY; ENVIRONMENTAL HISTORY; SEDIMENTATION;

FAUNA

Abstract : The present distribution of lowland fynbos of the southwestern Cape

coastal forelands occupies a unique yet threatened existence. Long renowned for

its extraordinary species richness, the lowland fynbos now reveals a decline in

diversity following the impact of recent European settlement. Fine resolution

pollen analysis, conducted on a dated sediment core from the Verlorenvlei,

reveals a 250 year pattern of debilitating vegetation transformation. The

arrival of European colonists in the area circa 1700 is noted in the sedimentary

sequence, not only with respect to change in the pollen spectra, but also

through concomitant changes in the nature and timing of sedimentation. The

rapid extermination of large mammalian fauna, overgrazing by domestic stock and

decades of agricultural mismanagement in the marginal landscape are considered

to be the principal factors responsible for deliterious alternations of the

natural disturbance regime.

Ref ID : 427

387. Beckedahl, H. Subsurface erosion near Oliviershoek Pass, Drakensberg. South

African Geographical Journal 59(2):130-138, 1977.

Reprint : Not in File,

Keywords : SOIL EROSION; KWAZULU NATAL

Ref ID : 428

388. Beckedahl, H., Bowyer-Bower, T., Dardis, G., and Hanvey, P. The geomorphic

effects of soil erosion. In: The geomorphology of southern Africa, edited by

Moon, B.P. and Dardis, G.F.Johannesburg:Southern Book Publishers, 1988,p. 249-

296.

Reprint : Not in File,

Keywords : SOIL EROSION; GEOMORPHOLOGY

Ref ID : 1326

389. Beckedahl, H.R. Surface erosion near Oliviershoek Pass,Drakensberg. S A

Geographical Journal 59(2):130-138, 1977.

Reprint : In File,

Keywords : EROSION; MODELS; RUNOFF

Abstract : Pipes, a form of subsurface erosion, are developed within the soil

near the Oliviershoek Pass in the Drankensberg. A soil analysis has been

conducted in order to establish possible reasons for their formation, and the

data so obtained were then evaluated in the light of existing theories. In

order to eliminate certain discrepancies, it has been necessary to propose an

alternative model. It is postulated that run-off concentrated by the relief is

trapped by the vegetation, and then percolates through the soil profile, flowing

out along a zone of increased permeability and removing a clay fraction with

high dispersion and suspension characteristics.

Ref ID : 820

390. Beckedahl, H.R. Erosion along the rock-dominated coast of Transkei,

southern Africa. GeookoPlus 1:24, 1989.

Reprint : Not in File,

Keywords : TRANSKEI; SOIL EROSION

Ref ID : 821

391. Beckedahl, H.R. Gully morphology as a function of physical soil

characteristics. GeookoPlus 1:24-25, 1989.

Reprint : Not in File,

Keywords : SOIL PROPERTIES; SOIL EROSION

Ref ID : 822

392. Beckedahl, H.R. Piping as a form of accelerated erosion within the

colluvial soils of the Transkei region of southern Africa. Unpublished paper

presented at COMTAG workshop on "Denudation processes and landuse problems in

Tropical Regions", Nairobi, Kenya, Aug.,12-22, 1991. 1991.

Reprint : Not in File,

Keywords : SOIL EROSION; TRANSKEI

Ref ID : 823

393. Beckedahl, H.R. Soil erosion problems: perceptions and priorities. Enviro

Teach 2:7-9, 1993.

Reprint : In File,

Keywords : SOIL EROSION; SOIL CONSERVATION; CONSERVATION

Notes : This paper argues that, unless a holistic (and realistic) approach,

which adequately considers all relevant causal processes, is adopted with

respect to soil conservation and soil management practices, it is unlikely that

those practices will be successful. It has been suggested that the quantitiy of

arable soil available in SA is decreaseing from 5,5ha per capita in 1970 to a

projected value of 1,5ha per capita by the year 2000. Even if these predictions

are exaggerated, the question remains: can we afford to disregard the problems

outlined in this discussion or is there not the need for creating a greater

public awareness of the issues, and dispelling the misperceptions that exist.

Ref ID : 824

394. Beckedahl, H.R. Subsurface erosion: natural process or hidden threat?

Conserva 8:14-16, 1993.

Reprint : In File,

Keywords : SOIL EROSION; EROSION

Notes : This article describes subsurface soil erosion (also referred to as

piping or tunnel erosion). It is a term used to describe the combination of

processes whereby soil particles are moved by water within and through the soil.

Ref ID : 825

395. Beckedahl, H.R. The problem of soil erosion in informal and semi-formal

urban areas. In: Field guide to the greater Pietermaritzburg and Sani Pass,

Natal Drakensburg, Areas, Field Excursion Guidebook, IGU-GERTEC/SAAG Conference

on Geomorphic Responses to Environmental Change, University of Natal,

Pietermaritzburg, edited by Grab, S. 1994,p. 6-9.

Reprint : Not in File,

Keywords : SOIL EROSION; SETTLEMENT IMPACTS

Ref ID : 826

396. Beckedahl, H.R. Soil loss in the Natal Drakensburg. In: Field guide to the

greater Pietermaritzburg and Sani Pass, Natal Drakensburg, Areas, Field

Excursion Guidebook, IGU-GERTEC/SAAG Conference on Geomorphic Responses to

Environmental Change, University of Natal, Pietermaritzburg, edited by Grab, S.

1994,p. 31-35.

Reprint : Not in File,

Keywords : SOIL EROSION; CONSERVATION

Ref ID : 827

397. Beckedahl, H.R. The relationship between sediment yield and path surface

material in the Royal Natal National Park.Anonymous Natal Parks Board. -23,

1995.

Reprint : Not in File,

Keywords : SEDIMENTATION; SOIL EROSION; CONSERVATION

Ref ID : 543

398. Beckedahl, H.R. Sub-surface soil erosion phenomena in Transkei and southern

KwaZulu-Natal, South Africa.University of Natal, Pietermaritzburg. , 1996.

Subsurface erosion forms have been regarded as a unique exception to the more

common surficial erosion forms such as rills and gullies, and have therefore

been viewed as being of little consequence for the total annual soil loss within

any given region. A total of 148 subsurface erosion systems occurring at 66

sites in southern KwaZulu-Natal and Transkei were analysed morphologically to

determine the significance of subsurface erosion within this region, and to

assess the extent to which the observed phonomena may be explained by current

theories. Based on morphological criteria related to the dimensions of the

subsurface erosion phenomena, it has been shown that there are five distinct

subsurface erosion systems namely scree slope systems; gully sidewall systems;

anthropogenically induced systems; systems associated with dispersive soils, and

seepage systems. It was further found that, under certain cirucmstances, the

sediment lost through surficial erosion can be increased a further 77% by

subsurface erosion and that subsurface erosion is spatially restricted to

particular slope units which are defined on the basis of the dominant geomorphic

processes. Although solid chemistry, in particular dispersion related to the

Exchangeable Sodium Percentage and the Sodim Absorption Ratio, is an important

factor in facilitating subsurface erosion, other factors are also important as

scree slope systems for example occur in soils which are completely non-

dispersive. It has been possible to demonstrate that there is a statistically

significant correspondence between the spatial orientation of subsurface erosion

systems (in particular soil pipes); the orientation of inter-ped surfaces and

the orientation of bedrock joints. The correspondence has enabled the

explanation of how the well documented phenomenon of structurally controlled

drainage basins may develop.Doctoral Dissertation.

Reprint : In File,

Keywords : SOIL EROSION; TRANSKEI; KWAZULU NATAL; EROSION

Ref ID : 828

399. Beckedahl, H.R. Aspects of subsurface erosion phenomena in eastern southern

Africa. Petermann's Geographische Mitteilungen (Supplement) 245-213, 1998.

Reprint : Not in File,

Keywords : SOIL EROSION

Ref ID : 830

400. Beckedahl, H.R. and Bird, J. Gully sidewall morphology as a function of

physical soil properties. Proc. IGU Prague Conf. on Environment and quality of

life.Anonymous Anonymous :234-240, 1995.

Reprint : Not in File,

Keywords : SOIL PROPERTIES; SOIL EROSION

Ref ID : 616

401. Beckedahl, H.R. and Dardis, G.F. The role of artificial drainage in the

development of soil pipes and gullies: some examples from Transkei, Southern

Africa. In: Geomorphological studies in southern Africa, edited by Dardis, G.F.

and Moon, B.P.Rotterdam:Balkema, 1988,p. 229-245.

Reprint : In File,

Keywords : SOIL EROSION; TRANSKEI; COMMUNAL AREA; RUNOFF; EROSION; SOUTHERN

AFRICA

Notes : Artificial channelling of overland flow through road culverts has

resulted in the rapid development of soil pipes, micro-topographic depressions

associated with sub-surface cavities, and gullies. Concentration of surface

runoff as a result of channelling has enhanced rates of infiltration in discrete

parts of the soil system. This in turn has resulted in the development,

initially, of subsurface cavities and soil pipes, rather than unconfined soil

erosion forms such as gullies. This suggests that subsurface dissolution

processes may play a major role in the initial development of gullies in

colluvium-mantled terrain in southern Africa. Some problems and implications

for road construction, and the potential effects in terms of soil erosion in

sensitive terrain, are discussed.

Ref ID : 829

402. Beckedahl, H.R. and Slade, D.G.B. Minimise soil loss in urban areas.

Muniviro 9(3):12-14, 1992.

Reprint : Not in File,

Keywords : SOIL EROSION; SETTLEMENT IMPACTS

Ref ID : 121

403. Beckerling, A.C., Trollope, W.S.W., Mbelu, M.M., and Scogings, P.F.

Simplified techniques for assessing veld condition for livestock production in

the Ciskei region.Anonymous Ciskei:ARDRI, University of Fort Hare. :2-76, 1995.

Reprint : In File,

Keywords : CISKEI; COMMUNAL AREA; PRODUCTION POTENTIAL; STOCKING RATE; VELD

CONDITION; EASTERN CAPE; LIVESTOCK PRODUCTION; RURAL DEVELOPMENT; SOUTHERN

AFRICA

Notes : This report was written as a result of a project conducted by the

Department of Livestock and Pasture Science under the auspices of the

Agricultural and Rural Development Research Institute (ARDRI) at the University

of Fort Hare and was funded by the Development Bank of Southern Africa.

Ref ID : 1916

404. Begg, G. The estuaries of Natal. Natal town and regional planning

commission report no. 41.Anonymous Pietermaritzburg:Natal Town and Regional

Planning Commission. 41, 1979.

Reprint : Not in File,

Ref ID : 1917

405. Begg, G. The comparative ecology of Natal's smaller estuaries. Natal town

and regional planning commission report no. 62.Anonymous Pietermaritzburg:Natal

Town and Regional Planning Commission. 62, 1984.

Reprint : Not in File,

Ref ID : 1235

406. Behnke, R. Open-range management and property rights in Pastoral Africa: a

case of spontaneuos range enclosure in South Darfur, Sudan. Pastoral Development

Network 20:1-29, 1985.

Reprint : In File,

Ref ID : 1236

407. Behnke, R. New directions in African rang management policy. Pastoral

Development Network. 32:1-15, 1992.

Reprint : In File,

Keywords : POLICY

Ref ID : 1230

408. Behnke, R. Natural resouce management in pastoral Africa. Development

Policy Review 12(1):6-27, 1994.

Reprint : In File,

Keywords : LAND USE; POLICY

Notes : Current research on rangeland ecology suggests that we have less to fear

from pastoral land stewardship than was previously thought. On the one hand,

the natural environments exploited by pastoralists are generally robust and

resilient. And on the other hand, pastoral techniques of land management are

not as dysfunctional as was once widely assumed. While regulation of pastoral

activity may be necessary in specific circumstances, there no longer exists a

broad scientific mandate to control or modify almost every aspect of pastoral

land use in order to preserve the environment. This article tries to do two

things. First, it attempts to justify in some small measure the assertions made

above. It then examines the adjustments in African range management policy

which would be required if these assertions are substantially true.

Ref ID : 1231

409. Behnke, R. and Kerven, C. Redesighning for risk: tracking and buffering

enviromental variability in Africa's rangelands. London:ODI. , 1994.

Reprint : In File,

Notes : 'Arid and semi-arid lands cover about one-third of the earth's land

surface, but nearly two-thirds of the African continent. The majority of

African livestock and possibly 30 million livestock-dependent people reside in

these dry zones along with the greatest and most diverse concentrations of large

wild mammals in existence' (Ellis, 1994). Of the world's 20 poorest countries,

many are situated here. Considerations of economic importance, environmental

interest, geographical extent and human welfare suggest that African rangelands

should be high on the development agenda. They are not. This paper discusses

some of the reasons for neglect, and proposes some remedies.

Ref ID : 1229

410. Behnke, R.H. Measuring the benefits of subsistence versus commercial

livestock production in Africa. Agricultural system 16:109-135, 1985.

Reprint : In File,

Keywords : BOTSWANA; POPULATION

Notes : Three methods for measuring the benefits of commercial and subsistence

livestock production in Africa are discussed. Firstly, biological measures of

herd performace are illustrated with material from Botswana. Seondly, the

profitability of the herding operation can be measured economically, a technique

which requires the ascription of cash values to in-kind produce. An improved

method for imputing these values is presented. Finally, one can compare the

nutritional status of human populations engaged in commercial and non-commercial

livestock production. Each of these three techniques provides a limited

description of the total environment which conditions farmer decision-making.

As a general rule, therefore, we should favour a combination of techniques and

exercise considerable skepticism in evaluating the results of any unidimensional

comparison.

Ref ID : 1635

411. Behnke, R.H. Economic Models of Pastoral Land Tenure.Anonymous Overseas

Development Institute. :1-11, 1991.

Reprint : In File,

Keywords : MODELS; LAND TENURE; POLICY; FARMING SYSTEMS; AGRICULTURAL

DEVELOPMENT; PRODUCTION POTENTIAL; VELD MANAGEMENT

Notes : This paper tries to make two points. First, it has shown that property

rights analysis provides a simple framework for analyzing pastoral tenure

systems and changes in these systems. While the model presented here requires

both theoretical elaboration and ethnographic substantiation, the logical

structure of the model is clear, susceptible to disproof, and presentable in

plain English. In other words, the model should appeal to policy makers if it

can be shown that the model has more than trivial implications for the design of

applied range research and development programmes. And this is the paper's

second point. Range management programmes guided by property rights approach to

tenure issues would be different from current programmes. The full extent of

these differences is difficult to predict, since much depends on the ingenuity

of field workers as they confront old problems with new analytical tools. The

preceding discussion strongly suggests, however, that there is much more that

can be done with pastoral range management than give new names, and new

theoretical justifications, to what amounts to either individual or group range

management schemes.

Ref ID : 1640

412. Behnke, R.H. New Directions in African Range Management Policy. Pastoral

Development Network.Anonymous London:Overseas Development Institute. :1-15,

1992.

Reprint : In File,

Keywords : POLICY; ZIMBABWE; BOTSWANA; INSTITUTIONAL ASPECTS; LEGISLATION;

SOCIOECONOMIC ASPECTS; VELD MANAGEMENT; GOVERNMENT INITIATIVES; ENVIRONMENTAL

POLICY

Notes : This overview essay provides the background document for a workshop