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Ali Koç 1, Taşkın Öztaş 2 , Lütfü Tahtacıoğlu 3 1 Atatürk University, Agricultural Faculty, Department of Field Crops, Erzurum, Türkiye 2 Atatürk University, Agricultural Faculty, Department of Soil Science, Erzurum, Türkiye 3 Eastern Anatolia Agricultural Research Institute, Erzurum, Türkiye ABSTRACT In order to supply food requirement of increasing world population, the increasing pressure on natural resources has led degradation of these resources. Owing to this process, productivity and biodiversity has been decreased. These negative progresses consequently has caused the expansion of the global problem of desertification. From Turkiye point of view the situation is not so different; to meet the food demand of increasing population, large amount of land, rangelands in special had been unconsciously converted into cultivated land in the past. Hence, the pressure on rangelands has been increased and degeneration of plant cover has been started. Over grazing which led to deterioration of plant cover on rangelands, was initiated in fifties and has been continued up until today. Nowadays, no single rangeland left, which do not need rehabilitation in the country. If the current pressure on rangelands is maintained, desertification of large amount of land especially rangelands, will be inevitable in near future. Therefore, control measurements should be taken soon. For this reason, preparation of adequate land tenure and range management plans which consider rangeland and livestock interactions should be accomplished. INTRODUCTION In line with growing global population, increased food demand has forced the enhancement of agricultural production. As a result, environmental pressure has increased, this subsequently accelerated deterioration of natural resources. For instance, today, Mesopotamia-Basra-Nile which was known as productive crescent, has largely been desertified. At present, some 50.000-70.000 km2 land is off production due to desertification (Kömütcü and Erkan, 1998). Arid and semi-arid regions more severely suffer from desertification. In general, desert can be defined as; land with low rainfall (less than 200 mm), prevailing irregular climatic conditions, unproductive and narrow biodiversity. However, desertification was defined as "the land degradation in arid and semi-arid areas, caused by climatic changes and human impact" in United Nations Environment and Development Conference which was held in Rio de Janeiro in 1992 (Görcelioğlu, 1992). In this definition it was emphasised that, desertification was not the only the problem of arid zones but also semi-arid zones. Although, depending on years, characteristic desert climatic conditions may be seen in Central and South Eastern Anatolia in some years (Görcelioğlu, 1992), when the long term climatic date taken into account, there is no land in our country where desert climate prevails. However, if the definition made in United Nations Environment and Development Conference taken into consideration, we should accept that a major part of our country under the risk of desertification. Because, with the exception of Black Sea Region, semi-arid climatic conditions prevail in Türkiye. The effect of increasing pressure on natural resources has an important impact on the exhibition of desertification in any place, The continuity of pressure on natural resources finally turns out as desertification. Therefore, desertification comes out as a result of certain processes. The main problem in our country is the formation of desertification after degradation of natural resources through erosion. In this respect, the rangelands are subject to the highest erosion risk in the country. Because, rangelands generally are located on steep semi-arid zones and they are sensitive to erosion. In order to emphasise desertification problems in Türkiye, we should delineate the changes in the use of natural resources, rangeland management in special in our history. The Changes in Land Use Systems in The Near History of Türkiye : The changes in land use from the establishment of Republic of Turkiye up to now, are presented in Table 1. The table shows that there was no significant change in land use system until 1950. Whereas, after these years, with rapid expansion of cultivated land, shrinkage of rangelands had been observed. Until seventies there had been no change in forest land, but with the legitimisation of a new forest act, the forest land was nearly doubled in 1970.  The Changes in Agricultural Lands : In order to determine livestock rangeland interactions in Turkiye, the changes in agricultural land use system are to be worked out. The cultivated agricultural land had been 15.7 million ha in early days of Turkish Republic and there was no considerable change until 1950. Cultivated land had rapidly expanded between 1950-1960 then it has kept a declining trend. To figure out the reasons of this rapid expansion, it is necessary to examine population growth and wheat production which is an outstanding principal crop for nourishment of our people (Table 2).  It is well known that wheat has a special role in the nourishment of Turkish people. Thus, in order to meet the food demand of growing population some solutions were sought to improve production. Until 1950, the wheat production had been increased through the increase of wheat acreage in existing cultivated land, but between 1950 -1960 governments adopted the policy of increasing wheat production through expansion of cultivated land. In addition to population growth, the increasing tractor number (Table 1) which enabled farmers to cultivate large amount of land, was also effective. In this process a great amount of rangeland had been converted into cultivated land. At the end of this period there was no land left to open up for cultivation so that the idea of improving production through the increase of yield was anticipated. Evidently, there has been no increase in cultivated land after 1970 , even a trend of slight decrease has been observed. In comparison to thirties, against the doubled cultivated land and tripled wheat acreage, per capita wheat production was only doubled. The Changes in Rangeland Areas : The rangeland area was 44.5 million ha in 1930 and fell down to 37 million ha in fifties then it kept a trend of rapid decline until 1960 (Table 1). The increase in cultivated land was the single reason of the shrinkage of rangelands in that period. The decrease in rangelands in seventies was attributed to the classification of shrub land and within forest rangelands as forest land. Quite the contrary, with decreasing rangelands, livestock number was increased in this process. In line with increasing livestock number the acreage of fodder crops has not been able to expanded so that rangeland depended livestock production system became dominant. Hence, over grazing pressure on rangeland was increased deterioration of rangeland was initiated. Some indicators, between livestock and rangeland interaction are presented in Table 3.  In 1930, Turkiye had 10 million LU and it did not significantly changed until 1960. Animal population rapidly increased between 1960-1980 then it kept a decreasing trend after 1980. Naturally with decreasing rangeland areas the stocking rate gradually increased. At the beginning, the stocking rate was around 0.22 (LU per ha) and it has been increased to 0.62 at present. In other words, the rangeland area per LU has dropped from 4.55 ha (in thirties), to 1.67 ha in year 1997. However, at the present the optimum stocking rate calculated as 0.2. It is estimated that, available forage production at the beginning of overgrazing was 700 kg/ha and it dropped to 400 kg/ha at present. Research results and rangeland surveys (Koç et al. 1994; Büyükburç, 1997) also confirm this estimation. Based on this evaluation, hay production on rangelands has dropped from 31.2 (1930) million tones to 10.9 million tones in 1997. When the winter and summer feed requirements are considered the calculations indicates around fifty percent feed gap between requirement and supply. A significant negative correlation is observed between the changing overgrazing pressure on rangelands and rangeland productivity. The values in Table 3, was calculated considering optimum range management principles. These values show us that our rangeland was not subject to overgrazing until 1950 and after that intensity of overgrazing gradually increased. Grazing period changes between 150-210 days in our country (Bakır, 1987). With a pessimistic approach, if we take 200 days, we may claim that our rangelands are grazed 2-3 times more intensely than their carrying capacity. Rangeland Management Systems Applied So Far : Traditionally farmers tend to graze rangeland as long as climatic conditions are favourable for grazing. Thus, grazing is continued all year round in warm areas. On cold highlands grazing starts with the melt of snow in spring and continues until the snow fall in autumn. When rangelands are grazed, the basic principles of range management such as, carrying capacity, grazing season and grazing rotation never taken into account. Therefore, all types of misuse of rangelands can be observed in our range management system. If the existing conditions are maintained, rangelands inevitably will be out of production in near future. If the regulations foreseen in rangeland act which was legitimised in 1998 are put into practice, we may overcome these management problems. However, the lack of reliable statistical data and information on regional rangeland, make the preparation of future rangeland management plans difficult. Livestock Number and Feed Requirement During Grazing Period : We may evaluate the existing status with the assumption of putting rangeland act into practice; with respect to 1997 statistics, out of 13 million LU in the country, 1.2 million LU composed of exotic breeds and 2.6 million crossbreeds. With a rough estimation, 2 million LU are expected to feed inside and 11 million LU are expected to graze on rangeland for 200 days. Daily forage consumption per animal is calculated as 10 kg (Holechek et al., 1995), so that 22 million tones of forage is needed for grazing period. Since the forage production in rangeland is around 11 million tones (Table 3), we may conclude that this production is just enough for half of the existing animal population. If the shrub land and within forest rangelands are taken into account forage gap may be reduced. Forage production from these areas is estimated as 5 million tones (1 million ton from within forest rangelands, 4 million tones from shrub lands) and accordingly final forage gap is estimated as 6 million tones for grazing season. Present Status of Rangelands : Because of the reasons explained in ongoing paragraphs, rangelands have severely degraded. According to Gençkan et al. (1990) our rangelands has lost 90 % of their climax vegetation. This definition reveals the dimensions of rangeland degeneration in our country. Quite a big amount of studies on rangelands have been reviewed by Koç (1995) who emphasised that with respect to degradation gradient rangelands in our country were in poor and moderate categories and the degradation was too severe in lower altitudes and range conditions improve with increasing elevation. In arid and semi-arid environment, for the recovery of original vegetation in degraded rangelands in seconder succession, more than a human life time is needed (Herbel and Pieper, 1991). When the canopy cover drops below 30 %, with regard to erosion the threshold level exceeds (Marshall, 1973). The surveys proved that canopy cover in our rangelands varied between 10-35 %, but in general it was below 20 %(Koç, 1995). This situation help us to understand, how serious the risk of erosion in our rangelands. In other words, with the exception of some alpine and forest rangelands, there is no rangeland left which does not requires rehabilitation. Present Status With Regard to Desertification : One of the environmental problem in our country is the arise of desertification through the erosion and lose of soil productivity. There are different estimations about the dimension of erosion in our country. However, according to quantitative date, (Dursun, 1998) 400 million tones of fine textured soil is lost through erosion every year. Apparently, 0,5 mm of topsoil is eroded every year. The water is the main erosive factor in the country. Because, out of 66.9 million ha erosion threatened areas, only 0.33 million ha is under the risk of wind erosion. Around 90 % of non-cultivated land are subject to erosion. Thus, in desertification control measurement, these lands should be given priority. One of the main indcator of desertification on rangelands is the gradual decrease of perennial species in plant composition (de Soyza et al., 1998). The increasing intensity of annual species in plant composition on lowland rangelands , is the solid evidence of desertification in our country. If we insist not to consider rehabilitation measurements in the utilisation of our natural resources, the further deterioration of existing feature will be inevitable in near future. If the current misuse of rangelands is maintained, the degradation of plant cover will continue and after certain stage quite a large amount of land will be denuded. Under this circumstances surface reflectivity will change, leading severe differentiation of cloud formation and daily temperature changes (Thurow and Taylor, 1999) and consequently absolute desert climate will arise. At that time, the main erosive power in our country will be the wind. Under these conditions, for the recovery of original vegetation, much more labour, technology and time will be needed. That's why, we should slow down the degradation pace to an acceptable limit. To help slow down this trend and to stop deterioration of rangeland, there is an urgent need to develop appropriate measures to restore feed resources, along with to lessen erosion risk and loss of biodiversity on rangelands. Principally, erosion is common in 250-1000 mm precipitation belt (Thurow, 1991). In general, the rangelands intensively located in this precipitation belt in the world (Holechek et al., 1995). Therefore, like global consideration, in the control of erosion related desertification, rangelands have a special place. Since, 80 % of land under erosion risk in the world consists of rangelands (Thurow, 1991). Low income is the main reason behind the lack of effective erosion control measurements on rangelands. In addition to loss of feed resources, because of high run off water and floods, this type of land threaten the arable land, residential areas, irrigation and road schemes and dams. If the current rates of degradation continue, most rangelands will be destroyed as an economic resource, and will not be capable of economic rehabilitation. With Regard Desertification, Recommended Control Measures on Rangelands : Precautions for the improvement of productivity, alleviation of erosion and establishment of a sustainable management system on rangelands. a. In order to determine current situation of rangelands, assignment and determination of rangeland which were foreseen in 1998 rangeland act should be accomplished as soon as possible. For this objective; the criteria for the classification of rangelands at national level should be defined. In these criteria, with respect to grazing and erosion, rangeland health, threshold level should be determined and improvement measures should be launched accordingly. b. For assignment, restriction and determination studies, fast and effective new technologies such as Geographic Information Systems, Remote Sensing and aerial photograph should be employed. c. After classification, preparation of action plan to ensure the use of rangelands according to management principles and investigation of appropriate improvement methods for degraded rangelands should be initiated in a rational sequence. d. For the control of desertification in the country, cultivation should be stopped on marginal land which comprises 6 million ha (Cangir and Boyraz, 1996) and is not suitable for crop production. After the rehabilitation process this land should be regained to rangeland. e. In action plans, for the alleviation of feed gap alternative solutions should be created. f. The infrastructure for the provision of plant material, which is needed in rangeland rehabilitation work, should be established. g. Fodder shrub should be given first priority in the rehabilitation of denuded step rangeland. Because of their intensive root structure, fodder shrubs are very efficient in the rehabilitation of denuded rangelands (Le Houreou, 1998). h. Pasturalists should be trained about the range management, they should be consulted about implementation and their active participation to range management should be supported. It is possible to double the production through the rehabilitation of our rangelands. In that case, our rangelands may be sufficient for the current animal population. In addition, regain of marginal unproductive land; will help compensation of feed gap. One of the fundamental improvements is the development of preparation of land utilisation plans. In the preparation of these plans, livestock rangeland balance with special consideration to soil conservation should be established. REFERENCES Bakır Ö., (1987). Çayır-mer'a amenajmanı. AÜZF. Yay. No: 992, Ders Kit. 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Le Houerou H.N. (1998). Utilisation of multipurpose fodder trees and shrubs in the arid and semi-arid Mediterranean Zones of West Asia and Northern Africa: an overview. Fodder Shrubs: Their Role In Mediterranean Arid and Semiarid Land Development and Environmental Conservation Course, 28th Sept. to 9th Oct., 1998, Rabat, Morocco, 51 p. Marshall J.K. (1973). Drought, land use and soil erosion. In the environmental, economic and social significance of droght. (Ed: J.V. Lovett), Angus and Robertson Publ., Inc. p. 55-77. Thurow T.L., Taylor C.A. (1999). Viewpoint: the role of drought in range management. J. Range Manage., 52: 413-419. Thurow, T.L. (1991). Hydrology and erosion. In grazing management an ecological perspective (Ed: R.K. Heitschmidt and J.W. Stuth), Timber Press, Inc., p. 141-159. |