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Review of the discussions

The discussions were preceded by interventions by LE HOUEROU, BOUDET, DAWSON, TRUMP and GWYNNE.

Intervention by H. Le Houerou
Intervention by G. Boudet
Intervention by N. Dawson
Intervention by E. Trump
Intervention by M. Gwynne

Intervention by H. Le Houerou

The first research on rangeland in Tunisia was undertaken after World War II, from 1946 to 1950, by Pottier-Alepetite and by Guinochet. These studies were of a classical phytosociological nature and strictly of "Sigmatist obedience" (*).

(*) Editors' note:

From 1950 to 1960, at the request and with the financial support of the Tunisian Government, a team of young scientists, having both agronomic and natural sciences education and training, and working under the supervision of Prof. L. Emberger from Montpellier, undertook a systematic inventory of the vegetation and plant communities of the whole country. This research gave rise to five theses for doctorates in natural sciences, which established what has now become the methodology of the Neo-Montpellier school (CEPE). Rangelands in the semiarid to humid bioclimatic regions (P > 400 mm) were studied by M. Thiault, forests by A. Schoenenberger, cultivated land by M. Gounot, and arid land (P < 400 mm) by G. Long (from 1949 to 1953) and by H.N. Le Houérou (since 1954), while at the same time G. Novikoff devoted himself to the study of halophytic plant communities.

This global inventory was completed by 1958/59, having required 30 research men/years; over a surface of 160,000 sq km about 1,000 plant communities were described and classified.

The duty of this team was to carry out an inventory for further phytoecological mapping at small and large scales, which in turn would be designed for land use planning and reclamation, including that of pasture, crop land and forests.

The first maps at the scale of 1/200,000 date back to 1954 and 1955 (sheet of Sbeitla by Long, sheet of Gabes by Le Houérou). Later on, from 1958 to 1966, all of the arid-zone communities were mapped at different scales, from 1/25,000 to 1/500,000 (Froment, Van Swinderen, Le Houérou); and a synthesis at the 1/500,000 scale (128,000 sq. km) by Le Houérou et al. was published in 1967. The cost of inventory and mapping at this scale was around US$ 0.10 per hectare (inventory, mapping, publication of colour maps and reports).

As a comparison, a survey area of 2.5 million hectares, with mapping at 1/200,000, in a similar zone in the Honda region of Algeria (Le Houérou, Claudin and Haywood 1975), cost approximately the same per surface unit between 1968 and 1972 (project UNDP -SF/FAO/ALG509).

Later on, from 1964 to 1967, the mapping of the whole of Northern Tunisia (35,000 sq. km; P > 400 mm) was covered by phytoecological maps at 1/200,000 and summaries at the scale of 1/50,000, with some additional inventory studies (Gounot, Schoenenberger, Floret et al., 1967-1969). The cost of the operation (including assessment of agricultural and economic potentials) was about US $ 0.30 per hectare, publication of colour maps and reports included.

The main characteristics of this inventorying and mapping originate from the fact that they are a direct result of the close collaboration among several specialists from different fields: phytoecologists, botanists, photointerpreters, soil scientists, range scientists, animal scientists, agronomists, climatologists, foresters, geographers, sociologists, economists, and planners.

Each mapped unit of vegetation and environment is given three levels of production for each of the main possible agricultural, pastoral and forestry speculations that can be envisaged:

- High technical level of management
- Intermediate level of management
- Traditional level of management

which makes it possible for economists to set up strict and objective agricultural planning in agreement with the economic and social options made available to the Government.

This, however, was possible only through permanent day-to-day dialogues held both in the field and in the office between specialists of the various disciplines involved.

Among the first applied studies carried out, one should mention: possible ways to expand the variety of date palm trees (Deglet Nour) in 1954; determining the oil production potential in Tunisia in the arid zone in 1958; various range studies in the central and southern arid zones from 1950 to 1968 (Long et al.). Alongside the phytoecological studies, experiments were undertaken in order to determine the primary and secondary production of natural pastures (Long, Le Houérou, Thiault, Froment, Sarson) as well as to establish artificial pastures (Corriols, Thiault, Le Houérou, Lapeyronie, Jaritz and others). While the studies and mapping of vegetation made the location for experiments possible for some plant communities selected because of their representativeness, that which guaranteed the results obtained is subject to generalization. The establishment of fodder shrubs and tree plantations (spineless cactus, spineless phyllodic Australian acacias and Atriplex, in particular) was intensively studied, demonstrated and extended in the arid zone (Froment, Franclet, Le Houérou, Sarson, Schweisguth).

A pasture development doctrine for the arid zone was thus progressively shaped, and was published in 1966 (Le Houérou and Froment). This doctrine, based upon surveys, demonstrations and real scale operations is characterized by:

- Limitation of stocking rate and rotation or deferred grazing;

- Complementarity between native pastures on the one hand and, on the other

a) Use of fallow and stubble,
b) Planting of fodder shrubs and trees,
c) Fodder crops either in dry farming (P 400 mm) or under irrigation (P < 400 mm),
d) Periodical use of protected areas (exclosures acting as reserves,
e) Use of concentrates and of agricultural and industrial by-products.

Later, beginning in 1970, large development projects were undertaken in cooperation with FAO and the World Food Programme, which enabled the planting of over 50,000 ha of fodder shrubs, mostly spineless cactus, within a five-year period in the arid zone. Based upon the above-mentioned principles, five pilot projects in range management, covering some 10,000 hectares in areas receiving from 150 to 350 mm of average annual precipitation, were established between 1970 and 1975. The level of security reserve feed in these pilot schemes is 20 to 30 percent of the annual feed requirement of the flocks. This rate is proportional to the aridity of the area. A pilot project study is underway in an area of 100,000 ha, where the average rainfall is 150 mm (Oglat Merteba).

These pilot range management schemes have been established after detailed range surveys and mapping at a scale of 1/25,000. The forage and water resources are carefully assessed as well as the feed reserve potential. The surveys end with a detailed management plan which is the basis of stocking rates, pasture rotation, feeding calendar, flock management schedules, etc. The pilot range management schemes are under the supervision and monitoring of the technicians who have conceived and established them, especially where range and flock management and reserves utilization are concerned.

At the same time detailed researches on primary and secondary range production are being carried out in the southern part of Tunisia. These include the study of correlations between production and water dynamics in the soil, runoff, water harvesting techniques, desertization, etc. This research is being carried out in the framework of a joint FAO/ UNESCO - CNRS (CEPE) -ORSTOM - INRAT project (Ionesco, Floret, Le Floch, Gaddas, Telahique, Hadjej, Pontanier).

In the northern part of the country, with semi-arid to humid Mediterranean climate, thanks to various FAO and bilateral projects (Sweden, W. Germany, France, USA) fodder crops and artificial pastures are being developed over several thousand hectares (Fetuque, Luzernes, Sulla, Trèfle souterrain, etc.). The gores in and the fringes around the forests are being sown to artificial grassland under intensive production, making it possible to remove the animals from those parts of the forests which are to be regenerated or planted.


One may say that in Tunisia we have a rather rare case where a certain number of phases have followed each other in a rational way for the last 25 years, i.e.:

1. Detailed inventory;
2. Mapping;
3. Experiments;
4. Demonstration;
5. Development.

This was made possible because of continuity in conception and action from a doctrine based upon ecological concepts.

However, there remain some dark areas: although Tunisia has benefited over the last 25 years from more than 100 expert/years in the fields of ecology and range science, the fact that very few Tunisians have been trained in these disciplines makes it obvious that without the help of national specialists in sufficient number and of adequate qualification, no large-scale development can take place in future.

It is therefore imperative that handing-over take place immediately, since otherwise a quarter of a century of effort, many talents, and large sums of money will have gone to waste.



The problem of bringing under control tracts of land is closely tied to land structures. How should this control be formulated so that it is acknowledged by the people? How well are you succeeding in convincing your own people?


In Tunisia, the problem of the nomads is nearly resolved: less than 20,000 remain. For twenty years there has been an unrestrained appropriation of land which makes it difficult to create livestock breeding cooperatives having sufficient pasturable areas, on account of the parceling out resulting from this appropriation. The Technical Services have succeeded in convincing the farmers to form fodder reserves (more than 10,000 hectare increase per year) but we have not yet succeeded in bringing the livestock breeders to a rational system for the management of pasturelands.


The ecological conditions of Tunisia are those of the Mediterranean basin and are not applicable to the tropical setting, namely to Mali. What's more, in Tunisia, there is little moving of herds, and the problems of nomadism being well controlled, the management problem of tracts of land is easy.


Tunisia is not really the Sahel. Yet important research work can be done on the local trees and shrubs whose biology, productivity, and fitness for cultivation are unknown. In addition, one could consider experimentation with native trees and shrubs from regions similar to South America or, especially, Australia. This is a research problem.


The work of Dr. H. Le Houérou in Tunisia must be taken as an example of method. The interest lies in the duration of the experiment and in the results obtained from a type of method worked with in Montpellier. It is necessary to insist on the interdisciplinary nature of the process, which has permitted studying the vegetation as the integrating force of all the factors of the surroundings.

All the research undertaken in Tunisia has been in sufficient detail that the results can be given directly to the users, that is, to the managers.


How has the animal and vegetal production evolved in relation to the management of tracts of land? In Senegal, after examining very summarily and from the outside the results obtained in Tunisia, one might propose, for example, the extermination of goats as a means for improving pasturelands. We wanted to extrapolate what has succeeded outside our country without taking into consideration specific conditions, and that seems dangerous.


Through experimentation the improvement of pasturelands of average quality can vary from 400 to 1,000 parts per 100 on damaged pasturelands. Practically speaking, the production of the tracts can double, on the average.

In Tunisia, the goat has never been eliminated in the arid zone but only in the semi-arid to humid where the forests are located. On the contrary, the goat is a necessary element for the rational improvement of pasturelands, and in northern Tunisia goats have been very rapidly coming back since 1969, to the distress of the foresters. This has resulted from political change in the country since September 1969.

Intervention by G. Boudet

Let's consider the following eight French-speaking countries of West Africa: Senegal, Mauritania, Mali, Niger, Dahomey, Togo, Upper Volta and Ivory Coast.

Their areas can be estimated at about 449 million hectares. It is good to remember that on these areas there are:

- more than 160 million hectares of desert zone,

- about 160 million hectares of Sahelian zone, strictly pastoral or at least dominantly pastoral,

- 113 million hectares of Sudanian and pre-forest zone where agricultural and pastoral livelihoods are mixed,

- and finally, about 14 million hectares where forestry is dominant.

It is possible to estimate that in 1974, on the whole of these areas, 76 million Sahelian hectares and 12 million Sudanian agro-pastoral hectares were studied, permitting the evaluation of potentialities. Specifically, a map representation of the results of soil research on large, small, and medium scales has been carried out.

What were the objectives and methods? The different tasks carried on in West Africa were conducted in a rather particular manner for several reasons, with interest in answering - before any other concern - the formulated or often vaguely sounded needs of the responsible authorities of the states concerned. There are other variations as well to improve he presentation of research results so as to satisfy the users.

What were the preoccupations of the directors of these studies?

- To specify the potentialities of the diverse settings we had to deal with.

- To specify as well the limits; the vegetation is the reflection of the conditions of the setting, but this is a perfect continuum, as our friend Raynal has said before.

It was necessary to be able to subdivide this continuum in a rational manner in order:

- To make the researchers' results explicit for the users. We are proposing better use of soils considering the observed potentialities, the land tenure, the traditional farming methods, and the known burdens on men as well as on livestock. We are, in fact, in a country that is not virgin! There are many people and a lot of livestock.

- To measure the resistance and the weakness of the ecosystems.

- And to predict - too often, unfortunately - imminent catastrophe (it seems that I am a pessimist !), so heavy is the burden on humans and animals. It is necessary to remember that the farming system is traditional; it is certainly adapted to the drastic conditions of the setting, but rather maladjusted to meeting the needs of the populations in the area and permitting them to survive.

Finally, it was necessary to propose to those responsible, if not to those who lent the money, some remedies capable of limiting, indeed reducing, the deterioration and desertification of the Sahelian pasturelands. In fact, it would be necessary to rapidly carry out the evaluation of the deteriorated areas. Recently I had the opportunity of spending four years in zones where the deterioration of pasturelands

- I will ask for the Chairman's authorization to tell you - has increased about 80 percent (that's excessive !) and to propose some simple measures for the defense and restoration of the soils, to the scale of millions of hectares of the Sahel. It would be possible to do this by cutting off certain sources of water and opening up others because, and I emphasize, there are many people and a lot of livestock. It would be necessary as well to redistribute the lands, taking into consideration the obvious variations in water and pastureland resources. It would be necessary to very seriously consider a distribution of lands by tracts in one form or another - on a medium-term lease - subject to a pastoral code that should be defined at the state level.

I tank you, Mr. Chairman.


Tunisia provides a good example of methodology. However, in spite of all efforts, a deterioration in the land is obvious. What are the results of the studies carried out in West Africa? Did they permit the emergence of regional development plans?

What are the methods used to study the resistance of the ecosystems to factors of deterioration?

Without having talked about the methodology used or the precise objectives alluded to, Mr. G. Boudet has proposed some solutions - among others, for the redistribution of soils and the problems related to landholding. Are these conclusions the results of his studies? On what factors can one rely in order to advocate solutions that will prevent the deterioration of pasturelands?


Couldn't we point out in our recommendations the problem of uniformity of methods, especially survey methods?


The inconvenience of limited travel for the experts since the independence of the African countries, ought to be compensated for by study programs of at least five years', duration for local researchers so that they can verify changes in pasturelands under different climatic conditions.

In the area of methods, we could utilize the computer, but because of a lack of time and means, the empirical processes are still in use.


The empirical method used in our zone called for two transitions: one in a favorable period, the other in an unfavorable period.

It seems preferable to me to attach much more importance to the regeneration of the land than to safeguarding the little that remains.

Intervention by N. Dawson

Thank you Mr. Chairman. I would like to talk for a very short time about the surveys that we are conducting in Queensland (Australia). These surveys are a reconnaissance inventory prepared by a multidisciplinary team. This means maps prepared at the scale of 1: 250,000. Since 1969 we have completed work on a hundred and fifty thousand square kilometres and have five hundred thousand square kilometres presently under study. The total cost of our work is approximately one cent American per hectare. The area receives less than five hundred millimetres of rain per annum.

Objectives of the surveys were outlined to the team by the State Land Development Committee. They were to map the different land types and identify the basic ecological characteristics of each land type. From this we are to develop guidelines for the formulation of land management and administrative policies, these particularly in the development planning and land tenure fields. As well, we are to provide basic information on the land and its problems to our research workers, extension workers and graziers. As such, our work provides the bench-mark from which future research and development can proceed.

Most people will have read my paper and I would not like them to get the impression from that paper that we are only dealing with computers, computer techniques, ERTS and other expensive, or what people might think expensive, techniques. Most of our data are based on intensive field work. I do not have the time to outline the principles used in the preparation of land inventory, and I believe that they are adequately covered in my paper. The major difference, I think, between our techniques and others, is in the degree of interpretation of the masses of data collected in the field. This has been made possible by using an efficient data base in a data bank and retrieval system.

All the data stored on computer tapes are easily and cheaply available to any interested person and I will stress this, cheaply. It is the cheapest form of processing. By using a data bank system, there is less chance of resource data being lost for use, and this has been a major problem in resource surveys in the past.

Finally, for a project to be successful we need:

1. that the survey team have contact with people who will be using the report all the way through the study; and,

2. that the survey people themselves follow through on the recommendations.

I have brought copies of our reports in Western Queensland and all the data sheets that we used, and I welcome anyone who wishes to view this material.

Intervention by E. Trump

As briefly as I can, ladies and gentlemen - seven years of work in about seven minutes. The rangelands of Kenya represent the basic resource on which two of the country's most important industries, that is, livestock production and tourism, are based.

With increasing population pressures and the growing demand for food crops, competition for land becomes ever more fierce. We shall lose some areas of rangeland to irrigation and others of better rainfall will be converted to crop land. This will inevitably lead to a decrease in the acreage currently devoted to grazing by livestock and wild game. In October 1963, the Kenyan Ministry of Agriculture very wisely decided to set up a Range Management Division. The new Division was given the primary responsibility for rational development of the rangelands, to be undertaken with full consideration of the ecological potential and with due regard to local requirements.

The government requested UNDP assistance in strengthening the new Division, and the Governing Council of the special fund designated the Food and Agriculture Organization as the executing agency of the project; the Government counterpart agency being the Kenyan Ministry of Agriculture. The range project was authorized in October, 1966, for a period of five years; it was eventually extended to seven years. A sum of two million, forty-seven thousand U.S. dollars was originally allocated by special fund for the work as against the government commitment, in kind, equivalent to one million, seven hundred thousand U.S. dollars. The project has been or was unique in that it was organizationally and physically an arm of the Range Management Division of the Ministry of Agriculture. In effect, the project not only had the responsibility for survey, research and education, but also the task of providing technical information for administrative decisions of the Range Management Division. The purpose of the project, as stated in the plan of operations, was to promote the pastoral development of the vast Kenyan range area. More specifically, the project was to strengthen the Range Management Division of the Ministry of Agriculture, to enable it firstly, to carry out land use surveys as a basis for detailed development planning; secondly, to provide training for range officers, field instructors and technicians as well as extension services for range farmers and pastoralists; and thirdly, to intensify applied research on specific problems of range development and productivity. These objectives had the dual purpose of increasing meat production from the range resource and of maintaining the rangeland ecology in a state which will ensure the continued aesthetic and economic attributes afforded by Kenya's wildlife.

The three objects of this project, survey, research and education, were intended to be complementary, each aimed at reaching and maintaining the highest possible production level of animal products, goods and services from Kenya's rangelands. The project concentrated on collecting as much data as possible on the rangeland surveyed and in making development proposals and recommendations based on these data. The research work was oriented towards investigations of immediate and high priority interest and in the development of a long-term research program with the trained manpower required. The education activities consisted mainly of developing a program and producing the necessary visual aids to effectively prepare the pastoralists for entering the market economy. The function of the survey section within the project was to begin an inventory of rangelands and so provide the government with the possibility of integrating the rangelands into the modern economy of the country. The survey team was formed in 1966 to include the disciplines of range ecology, water development, wildlife biology and livestock economy. It continued to function with various personnel changes until October, 1973, by which time 173,000 sq. km of the Kenya rangelands had been surveyed. Surveys were carried out at two levels.

The primary resource surveys were carried out in the areas of Kenya where rangelands may possibly be integrated with other forms of land use but which lacked evaluation upon which decisions for single or multiple land use development could be made. Primary resource surveys were conducted in some of these by an ecologist, using natural vegetation as the main key. An ecological analysis was made, interpreted primarily from vegetation patterns and supported by other factors for which data were available. Knowledge and experience were used to extrapolate ecological interpretations over large areas using aerial photographs as a tool. Potentials of various ecological complexes being known to the ecologist, these were used as the basis for recommendations to the government. The intensive development surveys were restricted to planning units where it was accurately known that true rangeland predominated. These studies necessarily assessed the potential from the viewpoint of the long-established land usage in which the true rangelands and adjacent high potentials were closely interrelated. In most rangeland, low and erratic rainfall and present range condition were the major factors limiting the effect of development inputs. Therefore, the ecological reports, defined in terms of climate, soils vegetation, topography and present range condition, indicated ecological land units of specific development potential. An estimate of the livestock production potential of these units was made and its possible realization with management and water inputs formed the basis of development plans. Management tactics recommended were widely variable and equated with the possible intensity of the developments and the need to control stocking rates, modify vegetation initially, and accommodate the traditional land usage by the pastoralists.

During the course of our surveys a fairly detailed form of survey procedure was worked out - I won't go into this at the moment as we are a little short of time; if anyone is interested I can indicate this to them. The logical steps and the control of a survey team I think were worked out up to a fairly high stage. During our work we found there were certain factors which were of vital importance in the survey of any given area. Basic criteria included firstly climate, including rainfall reliability, seasonal distribution and amount; secondly, the innate potential for water development in a given area, thirdly, the present range condition - this could be vital; fourthly, the people of the area, the people living there, their attitudes towards livestock change and changes in their traditional way of life, their numbers and their claims to land ownership; and fifthly, the productivity and potential of the existing livestock balanced against the range carrying capacity - including under this item the presence, if any, and efficiency of the livestock marketing infrastructure.

Finally, I would like to draw attention to two of our final recommendations, at least to pinpoint some of our problems on an international basis: firstly, range degradation was shown as continually becoming more widespread, and there is an urgent need to arrest this deterioration by conservation management and development following integrated surveys; secondly, the traditional dependency of nomadic pastoral peoples upon their livestock as their major food source remains, and this has permanent adverse effects upon the quality of those calves that survive early deprivation of food because of the human competition for the dam's milk. It is recommended that strong efforts be made to reduce the people's dependency upon milk by encouraging the use of alternative foods and ensuring that such food is available when required.

Thank you, ladies and gentlemen.

Intervention by M. Gwynne

Thank you, Mr. Chairman.

During the last decade the emphasis of ecological research in East Africa has changed, away from the single species study towards the multidisciplinary such as we have been talking about now.

In the last few years the result has been the gradual development within East Africa of the ecological monitoring concept. From its beginning, where methods were thought to answer relatively simple questions such as, how many animals do you have? Through intermediate, for example, where are the animals located and when do they move? To more complex, why are there so many and why do they move in the patterns they do, when they do? Up to the present, where one is asking what will happen to the ecology of an area if it is developed in some way, in other words, trying to obtain management information. Although widely used in East Africa, the ecological monitoring methods practiced there are not well understood elsewhere, and it's the purpose of my paper, which you will receive in due course, to present the methods and the history of them, and the arguments for using them in the way that we do. This will therefore form a reference.

Ecological monitoring uses data from three general categories: environmental, which includes data on climate, soils, topography, and floristic dynamics; fauna, including wildlife and livestock numbers, their distribution, population dynamics, habitat utilization; and the economical and political, and this includes data on current land use forms, projected land demands and national development goals. My paper considers only the operational aspects of collecting, analysing and interpreting data from the first two categories. Choice of collecting or sampling strategy obviously depends on the spatial and temporal distribution of the phenomena being measured.

It's convenient to classify the ecosystem attributes along a continuum of mutability. We have got three classes. There are those that you might call permanent, such as the soils, the drainage, water holes, and static animal features. There are those that are semipermanent: the plant physiognomy that includes the cover, the vegetation type, the plant community composition, zoogenic features such as wallows and salt licks, the distribution of non-migratory large mammal species and human settlement, villages, roads, farms and ranches. And then there are the ephemeral or seasonal attributes, rainfall, insolation, soil moisture, plant phonology, plant productivity, the distribution of migratory large mammal species, large mammal productivity, which includes reproductive state and condition, and so on, the large mammal population structure, fire, and surface water. To examine these, data are collected from the operationally separate levels, the ground, the air and space.

Aerial sampling is discussed first because of the development of more traditional ground techniques; it is already known, and it can be considered as a function of the aerial strategy. Similarly we have already talked about the satellite. The basis of our examination is the systematic reconnaissance flight (or SRF), and this is based on the use of light aircraft, flying on systematic grid coverage, at exactly defined heights, under controlled courses. In other words, it's possible to fly transects. The latest aircraft are equipped with instrumentation that will enable them to repeat flight lines and be only a few hundred feet out at the end. The first step in the programme is to overlay a grid; usually we use a 10 km square grid. The flight lines then take place at the centre, giving a 5 percent coverage or thereabouts. The basis of the aircraft is a crew of four. The speed is around 150 km per hour and we fly, for example, at 100 metres above the ground level, the height being controlled by radar-altimetre. Data are recorded on tape recorders and later transferred to card systems and magnetic tape. We have developed a series of subjective estimates of the various parametres that I have mentioned. The pilot is responsible for navigation; seated next to him is a Chief Ecologist recorder who notes, in the subjective way that we have mentioned, various items that we are interested in: the two rear seats are occupied by observers, who look at the ground through a system of streamers or transects which mark out at that altitude a certain distance on the ground - in other words - you know the ground area that you are looking at. Animal groups too large to count accurately, such as herds of sheep and goats, are photographed using large magazine, motorized automatic exposure cameras. We are experimenting with the use of a high resolution video camera to replace the observers, so that we remove observer bias or at least reduce it. It has play-back facilities and stop motion, which are required for examination, and it will enable us to get good population estimates with excellent confidence limits and to quantify vegetation and burn fire, growth stage and so on; the kind of thing we are recording on a subjective basis at the moment.

The frequency of the SRF is a function of cost and the rapidity of seasonal changes. And in East Africa we use it every month, every two months, every quarter, and every major season, depending on where we are operating. The cost of flying such a survey at the moment is currently around 25 U.S. dollars per 1,000 sq. km, but that does not include observer time and the cost of films and recording equipment. Data are transcribed directly onto computer coding sheets, and at this stage the distribution of animals, the greenness, water, vegetation type and so on may be plotted by hand on the gridded working maps. I have some examples which you can see in a minute. Data are also punched onto computer cards and transferred to magnetic tape. There are computer programs available in East Africa which will process this information in a few days and give you line-print, print-out maps of distribution and biomass. There are a number of things that can be gained from this kind of method. They are dealt with in my paper, and there is no time to discuss them in detail: there are methods available for sampling large mammal populations, to get population estimates and to obtain population parametres from low level aerial photography, such as has been done with buffalo, elephant and so on; we can size them, age them and do a lot of other things. We get a great deal of habitat information from this; landscape classification forms the background to much of this.

Ground sampling is the second layer which we are using and which forms the basis from which the first works: in other words you cannot do much in detail without adequate ground truth. This has been emphasized several times during the course of this meeting. Nevertheless, the SRF is a useful tool that will provide an immense amount of information in a very short time. Repetitive flying of this sort over the same area enables you to follow shifts in seasonal population of wildlife and of range livestock; it enables you to follow changes in habitat behaviour, in water; it enables you to develop reasoning, causative reasoning, for why these things are happening.

All of this is current practice in Kenya and Tanzania and has led the Government of Kenya to establish, with outside funds, the Kenya Rangeland Ecological Monitoring Unit. This is an inter-ministerial body that is composed of staff from the Ministry of Agriculture and the Ministry of Wildlife and Tourism. Its object is to regularly, routinely, survey the rangeland areas of Kenya on this three- tier basis, to make the data available to the decision makers in government, to develop systems for storage and data retrieval, and to build up a record of data that can be used for planning and development progress according to the current wishes of Government. We can discuss this in much more detail perhaps during the rest of the meeting.

I have, for example, not touched upon the ground sampling strategies for which we have developed a number of methods. Rainfall and soil moisture, rapid methods for determining soil moisture, are most important to what we intend to do and what we are doing. Similarly, the systematic ground sampling, which is essentially like what you do in the air, has led to a better understanding of the problems of animal distribution and of plant growth. They are using primary production biomass estimation methods. The other data contained in this paper will be brought out at a later stage. I would stress, however, that this is not a science- gone-mad affair; it is based on great studies on the ground: there are, for example, some 250 sites being installed throughout the rangeland areas where detailed ground studies will be made. Most of the data can, in fact, be dealt with by hand; it just takes longer; some of the work in progress at the moment is dealt with in this way, but computer facilities are available, and suitable programs have been developed. The basic productivity data gathered at these 250 sites will also be supplied to a group working with ERTS imagery in an effort to obtain or to devise a method for determining standing crop on a routine basis directly from the ERTS data. It remains to be seen whether this can be done; there are obvious problems. One of them, which we have run into, is that the spectral signature of basaltic soils, for example, completely masks that of the vegetation in many areas, necessitating quite different calibration techniques.

The Kenya Rangeland Ecological Monitoring Unit will become effective shortly. It is a bilateral aid agreement; the World Bank and Canadian International Development Association were the prime financial agents behind it. With that, Mr. Chairman, at this late hour I hope to call a halt.



Two questions: The first concerns the cost of using computers in northern Australia and in Kenya. The second is knowing if it is practical and reasonable, considering ease and stability of data, to use the same possibilities for computers in the countries of the Sahelian zone.


It is reasonable to use computers for regional studies. It is perfectly possible to foresee regional programs similar to those I have mentioned. The amount of researched details depends entirely on the objectives fixed by the governments of the territories concerned.

Ideally, it would be necessary to proceed to regional evaluation, but diplomatic problems risk making these evaluations more difficult than they ought to be.


The memorandum delivered by Dr. A. Diallo at the beginning of the meeting which concerns agrostological studies carried out in Senegal, can be summed up in the following manner. These studies have permitted the establishment of natural pastureland maps. Yet the methods used have not permitted the results to be utilized in the elaboration of development projects of the zones in question. In fact, the modifications of vegetation due essentially to different ecological factors which vary from year to year, the difficulty in estimating the food value of the pasturelands, the difficulty in interpreting correctly the photographic courses on a botanical plan, all pose the problem of validity for the information furnished. It is advisable not only to update this information but also intensify the studies concerning the physiology of the nutrition of the animals.


The results presented are taken essentially from computer analyses. For those who don't have a computer, is it possible to do the evaluation and go through all the data?


A processing of the data is perfectly possible without using a computer. It was done by hand during the last few decades in East Africa. It is only a question of time, nothing more.


We are renting a computer and we have an engineer 600 kilometres away who sends the data, which are then processed. If you compare the expense of a computer to the former expense you have a 10-fold reduction; but it is necessary to recognize that our salaries are higher. Whatever the reduction is, we are realizing a savings. That gives you an idea of the advantages of using a computer.


What is the cost and the duration of a program?


It's difficult to answer that question, because it depends on the objectives. The cost of a standard surveillance of pasturelands, including the flights to and over the areas, carried out each month during the wet season and every 3 or 4 months during the dry season, for Kenya, on a basis of 100 square kilometres, including soil inspection as well, the installation of neutron sounding and automatic reading of these soundings, etc., comes to a little less than one million U.S. dollars per year.

The total cost of a flight that gives you a certain amount of information is about 25 U.S. dollars per hour without counting salaries and equipment. To cover a surface area of 25,921 square kilometres (100 miles X 100 miles), it is necessary to count on 15 to 20 flying hours.


The first evaluations, in spite of their imperfections, have brought a certain knowledge about the setting. Considering the deterioration of tracts of land, the demographic growth and the recent dry periods, it is necessary to consider the evaluations as an integral part of the development process.

It would be necessary for the government to define a policy of pastoral development in such a way as to enable formulating their evaluation demands from a knowledgeable standpoint.

To carry out an evaluation, a multidisciplinary approach is desirable.

It would be necessary to train local personnel. Thanks to this the evaluation will be corrected, because the correction comes only from the land.

The development projects address themselves to the grazier and terminate at his level.

It is therefore necessary that a relay be established between the grazier and the personnel who carry out the pastoral evaluation.

In fact, pastoral development is a combination of actions and studies. It is therefore not necessary to wait for several years of work by experts before undertaking a development program, but this can be perfected as the data become available.

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