Availability of pasture for domestic and wild herbivores in grazing land of Mpanda Tanzania

P Y Kavana and V A M Kakengi*

Mahale-Gombe Wildlife Research Centre, P.O. Box 1053, Kigoma, Tanzania
pkavana2001@yahoo.com
* Tanzania Wildlife Research Institute, P.O. Box 661, Arusha, Tanzania
kakengi1@yahoo.com

Abstract

A study was conducted to assess feed resource base for domestic and wild herbivores in grazing lands of Mpanda district. Forage samples were taken from various grazing lands in wet and dry seasons.

Results indicated that feed resources for domestic and wild herbivores in Mpanda district is based on miombo woodlands vegetations. Various plant species were identified that indicate plants diversity in grazing lands. However, plant species edible to domestic and wild herbivores were 42.9% of the available plant species population in grazing lands. Furthermore, the edible plant species were confined to 9 plant families out of 39 plant families documented in the study area. This implies that feed resource base for domestic and wild herbivores in Mpanda district is narrow. Therefore effort through establishment of proper land use plans in villages is required to ensure sustainability of domestic and wild herbivores as well as feed resources in Mpanda district.

Key words: edible plant species, feed resource base, miombo woodlands, Mpanda district, plant families

Introduction

Natural pastures are the basis for ruminant livestock production particularly in traditional livestock sector of Tanzania. Pastoralists move from one place to another in search of pastures and water for survival and production of their livestock herds. Over  years, traditional livestock keepers have developed knowledge and strategies to survive the harsh and un-predictable conditions of the rangelands they occupy (Mwilawa et al 1998).The Sukuma people who are agro-pastoralists employed a copying strategy called ‘ngitiri’ and the Masai using ‘Olekeri’ to combat feed shortage during dry season. However, for a number of reasons their disaster coping strategies have become increasingly ineffective (Swift and Umar 1991) and poverty levels among them are rising. Livestock keepers in a traditional sector are therefore more vulnerable to a number of risks that are beyond the direct control of their communities. However, if practical solutions are set in place which addresses these risks, the traditional livestock sector cannot only continue to sustain the livestock keepers and dispose the rangeland resources, but also will significantly contribute to the national economy. Attempts have recently been made by various stakeholders in traditional livestock sector to reverse the situation (Coppock et al 2008). At the same time, assessment by planners and policy makers on development needs, priorities and goals of pastoralists are largely unreliable and often inaccurate. This is partly because of lack of adequate and reliable information on natural resources needs including pastures and natural resources utilisation for this community which is necessary for planning purposes. This has, among other things, contributed to the high rate of failure of traditional livestock sector development initiatives and conflicts with other natural resources users such as wildlife conservationists leading to the weakening of the pastoral resource base and feeling of marginalisation of pastoralists which poses a serious threat to their livelihoods. It is deemed that research on problems inhibiting traditional livestock sector development is needed to improve livelihood of pastoralists and harmony with other stakeholders.

Currently, there is an influx of pastoralists and agro-pastoralists in Ugalla ecosystem that poses game rangers to question about possibility of feed resources competition between domestic herbivores and wildlife in protected areas. The fact that Ugalla ecosystem is in miombo woodlands of western Tanzania increases doubt about sustainability of extensive grazing and agriculture in Ugalla ecosystem. Miombo woodland soils are naturally low in nutrients; the low nutrient status of miombo woodland soils is reflected in the widespread of traditional practice of various forms of shifting agriculture (Campbell 1996) and low quantity of feed resources to support large number of herbivores. Miombo woodlands are characterized with paucity of fauna (McNaughton and Georgiadis 1986) probably because of harsh and long dry season. The average biomass density of indigenous large herbivores in conservation areas in which miombo woodland is the sole or main vegetation type is 2.2 Mg DM (dry matter) km^-2 (East 1984). It was deemed therefore, important to assess the current situation of pastures in Ugalla ecosystem. 

Objective 

• To assess abundance of pasture in village lands allocated for animal grazing. 

Material and Methods

Study Location

The study was conducted in five villages that are within Mpanda district. Mpanda district lies between longitude 30^◦00’ to 33^◦31’ East and from latitude 5^◦15’ to 7^◦03’ South. It is located in the Western Rift Valley; it stretches alongside the shores of Lake Tanganyika and Lake Rukwa and reaches inland up to the Ugalla river system. Characteristic for the area are mountain ranges and highlands separated by depressions, valleys and plains. Average temperature range from 16 - 34°C with average annual precipitation of 767 mm. Economic activity of the majority residents is agriculture that include crop production mainly maize, paddy, beans and livestock production that include cattle, goats, sheep and chickens.

Assessment of pasture 

Assessment of pasture was done in the mid of April 2013 when the long rain was at the peak and >98% of vegetation was at full blooming stage. Five study villages located contiguous to the Ugalla ecosystem was involve in the study. Availability of pasture species in villages was determined using quadrants as sampling frame. Sample size (number of quadrants per location) was determined based on sample size for dichotomous data procedure as follows:

n = log (1-β)/log ρ, where. n=number of quadrants per location, β=Chance of detecting weeds in quadrants, ρ=proportion of pasture species in quadrants. Basing on findings reported by Kavana et al. (2007) the proportion of weed species at low, medium and high stocking rates were 20.2, 21.4 and 26.5% that makes an average of 22.7 ≈ 23%. Thus, on average, proportion of pasture species was 77%. Sample size was then calculated at 95% chance of detecting weeds as n = log (1 – 0.95)/log 0.77

n = log 0.05/log 0.77 = 11.8 ≈12 quadrants per location. However, the number of quadrants exceeded 12 for vast grazing lands. Plants falling within the quadrant area, were harvested at ground level and weighed for estimation of dry matter yield, identified and hand-sorted by species or species groups, counted and number of each species or species group recorded on the field records sheet for species botanical composition assessment. 

Socio-economic survey

Structured questionnaire was used to gather information on respondents’ knowledge about importance of wildlife, their attitude towards wildlife conservation and indigenous practices that enabled co-existence of human, wildlife and livestock in the past. Respondents were given opportunity to describe trends in production of both crops and livestock and suggest possible solutions to the problems they perceive. Environmental issues were discussed so as to obtain their perception on status of natural resources such as forest and feed resources for different types of livestock kept within the villages. 

Analysis of data

Descriptive statistics with chi-square measurements of contribution of plant families to edible plant species in grazing land was analyzed using SAS version 6.12.

Results and Discussion

Results on assessment of pasture species indicated that there were only 9 plant families in village grazing land that provide edible plant species for domestic and wild grazing herbivores out of 39 plant families recorded. A total number of plant species recorded was 168 out of which 72 plant species were edible to herbivores and the rest were non-edible which included forbs. A list of edible plant species recorded include:

Acacia horkii, Acacia sieberiana, Acacia tortilis, Amaranthus spinosus, Andropogon gayanus, Aneilema biflorum, Aristida kelleri, Brachiaria brizantha, Brachiaria deflexa, Canna indica, Chloris virgata, Commelina africana, Commelina benghalensis, Cynodon dactylon, Cynotis longifolia, Cyperus articularis, Cyperus cyperoides, Cyperus difformis, Cyperus dives, Cyperus esculantus, Cyperus involucratus, Cyperus papyrus, Cyperus rotundus, Dactylocteneum aegyptium, Dichrostachys cinerea, Digitaria brazzae, Digitaria macroblefara, Digitaria ternate, Diheteropogon filipendula, Dolichos kilimandscharicus, Echinochloa cruspavonis, Echinochloa pyramidalis, Eleusine indica, Eragrostis leptostachya, Eragrostis setulifera, Eragrostis spectabilis, Fuirena umbellate, Heteropogon contortus, Hibiscus diversifolius, Hyparrhenia diplanda, Hyparrhenia hirta, Justicia flava, Leersia hexandra ,Macrochloa tenacissima, Neonotonia wightii, Oplismenus undulatifolius, Oryza longistaminata,  Panicum maximum, Panicum repens, Panicum trichocladum, Pennisetum polystachyon, Panicum trichocladum, Pennisetum polystachyon, Pennisetum purpureum, Phragmates mauritianus, Pueraria phaseoloides, Rhynchelitrum repens, Sesbania sesban, Setaria homonyma, Setaria polystachyon, Setaria sphacelata, Sida acuta, Sida rhombifolia, Sporobolus africanus, Sporobolus fimbriatus, Sporobolus iocladus, Sporobolus pyramidalis, Sporobolus sanguineus, Tamarindus indica, Typha domingensis, Urochloa decumbents, Urochloa echinolaenoides and Vigna vexillata. Other plant species were identified and recorded that included Acalypha fimbriata, Acanthus ruelia, Acmella oleracea, Aeschynomene cristata, Ageratum conyzoides, Allophylus africanus, Asparagus africanus, Aspilia pluriseta, Bidens pilosa, Bidens schimperii, Blepharis attenuate, Boerhaavia diffusea, Chamaecrista hildebrandtii, Chamaecrista nemosoides, Cissus Antarctica, Cissus rotundifolia, Clerodendrum thomsoniae, Corchorus trilocularis, Crassocephalum integrifolia, Crotalaria laburnefolia, Crotalaria natalitia, Crotalaria nigricans, Crotalaria pumila, Crotalaria retusa, Crotalaria sagittalis, Crotalaria spinosa, Crotalaria zanzibarica, Cucumis aculeatus, Cyphostemma elephantopus, Cyphostemma serpens, Dicoma anomala, Diplorhynchus candylocarpum, Eichhornia crassipes, Euclea divinorum, Euphorbia cynadenium , Euphorbia hirta, Gardenia imperialis, Gutenbergia cordifolia, Heliotropium zeylanicum, Hoslundia opposite, Hygrophila spinosa, Hypoestes verticillaris, Indigofera brevifilamenta, Indigofera conjugate, Indigofera hidensis, Indigofera sessilis, Indigofera spicata, Ipomea cairica, Ipomea obsucura, Ipomea species, Kohautia confuse, Kotschya capitulifera, Leonotis nepetifolia, Lonchocarpus eriocalyx, Mapronea africana, Markhamia obtusifolia, Melanthera abyssinica, Mimosa pigra , Monechma debilis, Nymphaea caerulea, Ocimum americanum, Ormocarpum kirkii, Pistia stratiotes, Plectranthus purpuratus, Pluchea crenata, Plumbago zeylanicum, Pseudolachnostylis maprounefolia, Psilotrichum scleranthum, Rhoicissus tomentosa, Richardia scabra, Salvia azuera, Schrebera alata, Schrebera tricholada, Securindaca longipendiculata, Senna didymobotrya, Senna obstusifolia, Sesamum angolense, Sesamum calycinum, Sopubia trifida, Spermacoce sinensis, Spermacoce sphaerostigma, Spermacoce sphaerostigma, Striga lateritea, Tephrosia purpurea, Terminalia sericea, Thunbergia microchlamys, Tribulus terrestris, Trichodesma zeylanicum, Tridax procumbens, Triumfetta pubescens, Triumfetta rhomboidea, Vernonia galamensis, Vernonia pauciflora, Zehneria scabra, Ziziphus mucronata and Zornia setosa.

The list shows a diversity of plant species available in village grazing lands of Mpanda district. Despite high plant species diversity, 57.1% of available plants were not edible which implies that population of undesirable plants was higher than desirable plants for herbivores in grazing lands. This might be an indication of overgrazing that has been taking place in these areas due to influx of pastoralists to Mpanda from other parts of the country. The most edible plant species were from the grass family (Poaceae) as shown in Figure 1.

Figure 1. Contribution of plant families to the population of edible plants

The feed resource base for herbivores in grazing lands of Mpanda district is narrow as relied on 9 plant families (23.1%) out of 39 plant families recorded in the study (Figure 1). Comparison among plant families indicated significant difference (ᵡ²= 0.001) in contribution of plant families to edible plants population. Narrow feed resource base poses a threat to sustainability of herbivores in this area if no effort is taken to maintain these plant families against human activities that lead to overexploitation of plant species and effects of climate change on survival of these plant families. These plants exist in miombo woodlands whose soils are inherently low in nutrients. The low soil nutrient status of miombo woodland is reflected in the widespread traditional practice of various forms of shifting agriculture (Campbell 1996). Shifting cultivation  in grazing lands   lead to further decline of feed resources base for herbivores due to failure of disturbed plants to regenerate because of low soil nutrients and erratic rainfall. Relative low abundance of edible plant species observed in this study probably result in poor performance of domestic herbivores as they spend a lot of time in feed selection and movement from one site to another. 

Interview with livestock keepers on their perception with regard to feed resource base indicated that feed resource base declined in some villages (Table 1).

Further interview indicated that in periods of natural feed shortages particularly natural pastures, some of livestock keepers provide animals with non conventional feedstuffs such as crop residues, tree leaves and pods for survival (Table 2). Use of non conventional feedstuffs among livestock keepers varies depending on accessibility and availability. The main strategies applied by most of the livestock keepers include reduction of herd size by selling the animals and transferring of the animals especially cattle to other locations where pasture and water are available during that moment. Transferring of animals to other places has some implications as livestock keepers with large herds value their animals as liquid asset, and as they move to other places they cause increase in grazing pressure on miombo woodlands of Mpanda district. As they move to new woodlands they clear trees and burn woodland to create more pasture lands (Ghazi et al 2005). This tendency causes land degradation because as trampling caused by grazing animals loosen soil particles and subject the soil to wind and increase water runoff that bring about water erosion. With climate change effects and changes in land tenure policy, traditional livestock keepers in miombo woodlands might be entangled to the demise of their transhumant herding patterns.

Respondents in all villages indicated that competition for natural feed resources exist between livestock and wildlife. Elephant, buffalo and hippopotamus were considered by most of the respondents as the major competitors for natural feed resources against livestock in the study areas (Table 3). Low soil fertility and nutrient levels in true miombo woodlands limit productivity and favor a low biomass density of large wild mammals that is dominated by mega-herbivores. Other scientific findings indicated that elephant (Loxodonta africana) and buffalo (Syncerus caffer) make up 75-90% of the biomass at most of the true miombo woodlands, although both species are more abundant in drier savannas on eutrophic soils (East 1984). Their large body sizes allow them to utilize the abundant low quality plant matter present in miombo woodland. In addition, elephants can reach the substantial amounts of browse that are unavailable to other species.

Results from this study indicates that feed resource base documented in this study is important for sustainability of both domestic and wild herbivores. Therefore there is a need for district council to establish proper land use plans in villages that will ensure perpetuation of plant families that contribute to edible plant species for sustainability of domestic and wild herbivores in Mpanda district. 

Conclusion

• Feed resource base for domestic and wild herbivores in grazing lands within Mpanda district is narrow in terms of plant families that contribute to edible plant species

  
  

• There is an indication of feed resources competition between domestic and wild herbivores in areas located as grazing lands for domestic animals.

Acknowledgement

The authors wish to acknowledge the National Fund for Advancement of Science and Technology (NFAST) through COSTECH for financial support that enabled acquisition of data in study areas.

Reference

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McNaughton S J and Georgiadis N J 1986 Ecology of African grazing and browsing mammals. Annual Review of Ecology and Systematics 17, 39-65. 

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Received 26 December 2013; Accepted 29 January 2014; Published 4 February 2014

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