Balochistan is a vast arid and semiarid region situated in the south-west of Pakistan between latitudes 25 oN and 32 oN. It is the largest and most sparsely populated province of Pakistan, with an area of 34.7 million hectares. About 80% of the area can be classified as inter-mountainous. The remaining 20% consists of flood plains and coastal plains. The important mountain ranges are Sulaiman, Toba-Kakar, Central Brahui, Kirthar, Chagai, Raskoh and central Makran and Markan coast. The unfavourable topographic, edaphic and climatic conditions in Balochistan have restricted the area of cultivation, leaving most for rough grazing. About 93% of the area of Balochistan is classified as rangelands.
Balochistan ranges provide a diversity of uses, including forage for livestock, wildlife habitat, medicinal plants, watershed, fuel wood, and recreational activity. Rangelands are the major source of feed for 90-95% of sheep and goats. Sheep and goat rearing is the main use of these areas and about 80% of the rural population derive their livelihood from the sale of small ruminants and by products. Nomadic, transhumant, and sedentary are the three major grazing systems in Balochistan. Out of the total area of Balochistan, 21 million ha (60%) is used for grazing. Nearly 12 of the 21 million ha is classified as poor grazing, providing annually only 30-50 kg dry matter (DM) from a hectare, whereas only 2.9 million ha of better rangeland providing 250-280 kg DM from each hectare.
Overgrazing, drought and human disturbances caused severe degradation of rangelands in Balochistan. The degradation processes of rangelands include changes in composition of desirable species, decrease in rangeland bio-diversity and productivity, reduction of perennial plant cover, and soil erosion. A major concern of Balochistan ranges is the progressive reduction of productivity, elimination of desirable species, and how to manage and restore the health of these degraded ranges. Range and Forestry Research Programme of Arid Zone Research Center, Pakistan Agricultural Research Council is carrying out research activities to better understand the vegetation dynamics and improvement potential of arid and semi-arid ranges of Balochistan.
The main objectives of the Range and Forestry Research Programme are:
To characterize and monitor the rangeland resources.
To conduct ecological studies on native range species.
To conduct range restoration and rehabilitation studies.
To determine the nutritional and anti-nutritional compounds in range species.
To conduct ecological and agronomic studies on medicinal herbs.
To evaluate suitable fodder tree species.
Range & Forestry Research Program of BARC conducts research activities on a variety of issues like long term rangeland monitoring, evaluation of exotic and local germplasm of potential forage species for range improvement, ecological studies on native range species, seasonal variation in nutritional and anti-nutritional compounds of range species, and evaluation of potential medicinal herbs.
A wide range of germplasm of various species of grasses, shrubs, and trees were collected and range nurseries were established at BARC. Various species were tested in different ecological zones of Balochistan for adaptability, biomass production, and nutritional characteristics. Studies were carried out to determine the potential for biological recovery of heavily grazed grasslands by protecting the area from grazing. Long-term range monitoring studies were initiated to assess rangeland dynamics and trends in terms of biomass availability and permanent vegetation cover at different sites in Balochistan. Experiments were conducted to determine the above ground seasonal forage production and nutritional characteristics of Chrysopogon aucheri and Cymbopogon jwarancusa. Experiments were conducted to determine how seed attributes, seed dispersal mechanisms, seed bank dynamics, seed predation, and seedbed micro-habitat influences on the regeneration of Chrysopogon aucheri and Cymbopogon jwarancusa. Chemical composition of native shrubs and grasses (relative to nutritional needs of sheep, goats) and to relate that chemical composition to water use efficiency (WUE) as measured by the carbon isotope composition of leaves and stems of shrubs and grasses along a short topographic gradient were evaluated. Studies were also conducted to assess the nutritional status of sheep and goats grazing two rangeland types in Balochistan. These types are Artemisia maritime and Haloxylon griffithii association represented by the Zarchi (dist. Kalat) range and Cymbopogon-Chrysopogon at Tomagh (dist Ziarat).
Efforts are underway for the establishment of medicinal herb garden at BARC and introduction of potential medicinal herbs and spices as crops in Balochistan
Introduction of Atriplex canescens and Atriplex lentiformis in highland Balochistan
Atriplex canescens and Atriplex lentiformis commonly known as fourwing saltbush and Quail saltbush (Figs. 1 & 2) are exotic halophyte from the western United States. These are perennial drought and cold tolerant shrubs and can successfully be planted in areas with 250 mm annual rainfall.
Fig 1. Atriplex canescens plant with dense green foliage
These species start new growth in early spring that continues until late summer when moisture limits further growth. Micro-catchment water harvesting could enhance and prolong growth. A 1.0 m tall Atriplex canescens plant with 0.60 m crown diameter would provide about 0.25 kg dry matter as leaf and about 0.72 kg dry matter as wood. The amount of leaf offered each day, supplemented with wheat or barley straw or stubble, is sufficient to maintain the live weight of a sheep.
Fig 2. Atriplex lentiformis plants at seed formation stage.
A forage-reserve of 1 ha of Atriplex canescens with 2,500 plants would maintain 28 sheep with browse for three months in late summer, autumn, or winter when range vegetation is extremely scarce in highland Balochistan.
Feeding small ruminants on Atriplex alone is seldom recommended because of the poor energy value of the leaves and the associated moderate intake. Therefore, to obtain modest live-weight gain, supplementation is necessary either with barley or wheat straw. The protein content of Artiplex canescens leaves decreases from 25% in April to 10% in August and gradually increases during winter to about 20%. The netural detergent fiber (NDF) content peaked in May, decreased gradually during summer and autumn and recovered again during winter, whereas acid detergent fibre (ADF) content decreased gradually until September but then remained fairly stable.
Browsing of shrubs in forage reserves is considered to be the appropriate way to use Atriplex species, although cut and carry may be used in cases where farmers wish to cut large bushes for fuelwood and to encourage re-growth. Gently sloping valley bottoms of highland Balochistan are the most suitable areas for establishing Atriplex forage reserves. A package of Atriplex technology has been developed by BARC that addresses all related aspects of saltbush technology i.e., transplanting techniques and managing saltbush reserves for grazing and fuelwood production.
Introduction of Salsola vermiculata: A Self-regenerating fodder shrub
Salsoal vermiculata commonly called saltwort is an exotic Mediterranean arid zone fodder species (Fig.3). This species belongs to the Chenopodiaceae family. It is saline and drought tolerant, a good pasture species across all seasons and is palatable to small ruminants. S. vermiculata has the potential of self regeneration and establishment under good rainfall years.
Fig.3. Salsola vermiculata - a potential fodder shrub for range improvement in highland Balchistan.
S. vermiculata showed excellent survival under the extreme drought conditions of Balochistan. Forage production ranged from 250-650 kg/ha with an equal amount of wood production. Crude protein content ranged from 15-18%.
Eragrostis curvula: A potential grass for Rangeland Improvement
Cool and warm season exotic grass species were evaluated in different parts of Balochistan for their adaptability and biomass production. In Loralai, Eragrostis curvula (weeping lovegrass) showed excellent performance (Fig 4).
Fig 4. Eragrostis curvula (weeping love-grass) plantation in Tomagh (Loralai).
This is a warm season, perennial bunch grass. Dry matter production of weeping love grass in Tomagh (Loralai) ranged from 1945 to 2424 kg/ha. Crude protein content ranged from 8 to 10%.
Biological Recovery of Grasslands in Balochistan
Efforts were directed to understand the dynamics of biological recovery of degraded rangelands of Balochistan. Above ground biomass productivity inside exclosure vary from 224 kg/ha to 605 kg/ha compared to outside exclosure of 17 to 279 kg/ha. Grassland at Tomagh has responded more vigorously to protection and biological recovery. Heavily grazed grasslands of Tomagh has potential of biological recovery if protected from grazing at least for two years depending upon rainfall distribution.
Rangeland Monitoring Studies in Highland Balochistan
Long-term range monitoring studies were initiated to assess rangeland dynamics and trends in terms of biomass availability and permanent vegetation cover. The forage biomass data collected from the range sites in a typical mountain region indicate that the rangeland productivity is more a function of seasonal rainfall than the grazing pressure alone. Though the vegetation types (Artemisia-Haloxylon shrub steppe) in Hazarganji and Mangochar sites and (Cymbopogon-Chrysopogon mixed shrub grassland) in Tomagh range site are considered to be fairly drought resistant but the spring and fall season forage production showed a drastic low value at all sites due to drought during 1998-2002. However, low forage biomass values also indicate heavy grazing pressure during the drought years and therefore, reflect combined effect of both drought and the resultant heavy grazing pressure.
Seasonal Variation in Biomass of Chrysopogon aucheri and Cymbopogon jawarancusa in Highland Balochistan
Current season growth and nutritional characteristics of Chrysopogon aucheri and Cymbopogon jwarancusa were assessed on monthly basis at Hazarganji National Park. Above ground current season biomass production of both species peaked in June and then showed a declining trend. The current season biomass of Cymbopogon jwarancusa rangesd from 27 kg/ha in April to 51 kg/ha in June whereas Chrysopogon aucheria current season biomass production ranged from 2 kg/ha in April to 54 kg/ha in June. The trend of current season growth in 2002 was also similar to 2001 except slight increases in biomass due to better rainfall and availability of soil moisture.
The nutrition of both grasses decreased with the advancement of the phonological growth stages. In early spring, both grasses were of higher quality (nitrogen and phosphorous). The concentrations of K and Mg were below the recommended minimum requirements for small ruminants. Therefore, grazing management is required for better utilization of protected grasslands.
Regeneration ecology of Chrysopogon aucheri and Cymbopogon jwarancusa in grasslands of upland Balochistan
Experiments were conducted to determine how seed attributes, seed dispersal mechanisms, seed bank dynamics, seed predation, and seedbed microhabitats influence the regeneration of Chrysopogon aucheri and Cymbopogon jwarancusa. Cymbopogon jwarancusa was superior to Chrysopogon aucheri in several aspects of plant recruitment. Cymbopogon jwarancusa produced more filled and viable caryopses than Chrysopogon aucheri. Chrysopogon aucheri solely dispersed triplet spikelet, whereas Cymbopogon jwarancusa dispersed paired spikelets and groups of spiklelets (partial racemes, entire racemes, and partial inflorescens). Ant (Tica Verona) predators appeared to have a greater preference for Chrysopogon aucheri spikelets than Cymbopogon jwarancusa spikelets. Both species had a weakly persistent seed bank.
Both species are capable of natural regeneration when protected from livestock grazing; however, it appears that Cymbopogon jwarancusa has a distinct advantage over Chrysopogon aucheri during the initial stages of plant recruitment. Recruitment of both species is probably very sporadic because of the variability in the amount and distribution of precipitation within and between years. Regeneration of grasslands required proper grazing and protection from grazing to ensure seed production and reserves of soil seed bank.
Dietary composition and nutritional status of sheep and goats grazing two rangeland types in Balochistan
Studies were conducted to assess the nutritional status of sheep and goats grazing two rangeland types in Balochistan. These types were Artemisia maritime/Haloxylon griffithii association represented by the Zarchi (Kalat) and Cymbopogon-Chrysopogon at Tomagh (Loralai). Forage quality decreased with the advancement of phonological growth stages. Spring forage samples were of higher quality than those of other seasons. Grasses were lower in crude protein concentration and higher in netural detergent fiber content than forbs and shrubs. From March through October, sheep and goat diets varied in their botanical composition on both sites. Grasses remained a major component of animal diets at Tomagh throughout the grazing seasons. However, sheep and goats consumed a higher percentage of shrubs with the passage of time. Across all grazing seasons, the diets of both animal species were deficient in protein and phosphorus.
Highly variable (both positive and negative) digestion coefficients for lignin were obtained by using sheep and goat rumen liquors. As much as 51.0% of forage lignin in samples was digested. Negative lignin digestion co-efficients were also obtained from forage samples. These ranged from –1.0% to 103.0%. Lignin bio-degradation and/or complexing during in vitro digestion invalidated its use as an internal marker in digestion studies on these rangelands. The information can be utilized for successful range management including calculation of forage calendar, nutritional value of range plants and the cycle of nutritional requirements of the small ruminants.
Nutrient characteristics of foliage and the availability of water in a rangeland near Quetta
Chemical composition of native shrubs and grasses were determined related to water use efficiency (WUE measured by the carbon isotope composition of leaves and stems of shrubs and grasses) along a short topographic gradient at Hazarganji National Park. Communities at each point of the elevation gradient varied in species composition. At the lowest point, the grasses Chrysopogon aucheri and Cymbopogon schoenanthus were common. The dominant shrubs were Artemisia scoparia and Sophora griffithi. As elevation increased, these grasses were replaced by Bromus spp at a lower density, and the shrubs were replaced by Ferula ovina, Perowskia atriplicifolia, Prunus eburnea and Fraxinus xanthoxyloides, again at a lower density. At the highest point of the gradient, plant density was least and much less than at lower points. Caragana vlicina, Caragana ambigua and Ephedra intermedia dominated with a few scattered grasses.
The d13C data from Hazarganji strongly suggest that more water was available at the bottom of the elevation gradient (less negative d13C). The d13C data match the measured increase in non-protein nitrogen in shrubs and grasses with elevation. Plants accumulate non-protein nitrogen, mostly non-essential amino acids, in response to drought. The concentration of non-protein nitrogen would increase while that of total nitrogen will decline as plants mature and as water availability continues to decline later in the year.
The low N:P ratio of both shrubs and grasses is suggestive of an N limitation and is a common constraint to productivity in rangelands throughout the world. Nonetheless, at the time of sampling, all species, with the exception of the few annual grasses and Ephedra nebrodensis, had concentrations of nitrogen in foliage that were greater than the recommended minimum for ruminants. Concentrations of phosphorus and calcium were marginal for grazing ruminants except in a few species and Ca:P ratios were between 1:1 and 2:1 which is ideal for growth and bone formation. All shrub and grass species had lower concentrations of potassium than recommended. Magnesium concentrations were also low in all species. The preliminary studies of plant nutrition in Hazarganji Chiltan National Park has provided a single example of the effects of water availability on forms of N in forage plants (albeit confounded by changes in species composition along the gradient) and an overview of the variation in nutrient concentrations among species.
Introduction of Medicinal Herbs and Spices as Crops in Balochistan
Herbs can be used in many forms like flavors, spices, perfumes and medicinal ingredients. Most herbs contain essential oils (Volatile oils), which are responsible for the distinctive taste and fragrance. Other major chemical compounds include aldehydes, ketones and alcohols. In Balochistan, there are several medicinal plants, which are used, locally in traditional preparation but they have not been scientifically investigated so far for commercial scale production. Some of the potential aromatic/medicinal herb plants, which have potential to increase the income of local farmers of Balochistan, are Lavender, rosemary, mint, thyme, marjoram, oregano, basil, dill, sage, funnel, and tarragon. Efforts were directed for introduction of new spices/herbs in Balochistan farming systems, promotion of cultivation of medicinal herbs and spices in farming systems, agronomic research on medicinal herbs and spices for improvement in production technology at farmer’s fields and establishment of medicinal herb garden.
Experiments on various herbs are underway. Medicinal herb garden was established at BARC. Fifty five exotic species were raised at BARC Medicinal Herbs garden. These species have many uses for treating different diseases.
Through the integrated efforts of BARC and Balochistan Forest Department as well as NGO's such as FAO/UNDP Watershed Planning and Management and Integrated Range/Livestock projects, ADB Livestock Production extension Project, FAO Inter-regional Upland Conservation Project, seedling of fourwing saltbush and quail saltbush have been planted in various districts of Balochistan. BARC is also supplying seeds of Atriplex canescens and A. lentiformis to various NGOs and line departments for large scale nursery establishment in various parts of cold mountain areas in Balochistan along with technical know-how about nursery raising and planting.
Range and Forestry Research Programme of BARC in collaboration with OXFAM, Action Aid, and farmers of desert area of Nushki (Balochistan) has successfully planted two Atriplex species (Atriplex canescens and A. lentiformis) at Dhak area in Chagai district. Two nurseries were established near Nushki area for seedling multiplication of Atriplex and Salsola species.