**3.1 Characteristics of Tanzania's grasslands**

Grasslands are very diverse and widely distributed in Tanzania, with a range of dominant species depending on rainfall patterns, soil type, altitude, and management or grazing system. *Themeda triandra* is one of the most widespread grass species in Tanzania, and it is the dominant grassland type in central and northern Tanzania [9, 12]. However, the species is very variable and shows wide adaptation to growth in both the highlands and the lowlands. Themeda, Bothriochloa, Brachiaria, Sporobolus, Digitaria, and Heteropogon mixtures are common in the open dry areas such as the Serengeti plains (**Figure 3**).

Short tufted ecotypes of Themeda triandra are found at high altitudes and taller, more woody types are located in the open lowlands [9]. The dominant grass species in the drylands of central Tanzania include Cenchrus, Aristida, and Heteropogon. These grasses normally grow in association, and the establishment pattern of herbaceous plants is generally determined by the environment and soil texture [13]. Hyparrhenia, Hyperthelia, and *Pennisetum polystachyon* tall grass are common in the miombo woodlands of western Tanzania. The miombo forest is a vital vegetation type covering the southern two-thirds of Tanzania [14].

Pennisetum grasslands are classified into two types: high altitude grasslands of *Pennisetum clandestinum* and savannah grasslands of *Pennisetum mezianum* and *Pennisetum purpureum* [9, 15]. *P. clandestinum* is a prostrate stoloniferous perennial grass that is widely distributed in high altitudes (1400 m to over 3000 m.a.s.l *P. purpureum* is a tall, erect, vigorous perennial species that grows in damp grasslands and forest areas up to 2400 m.a.s.l.). At the same time, *Pennisetum mezianum* occurs in soils with impeded drainage heavy clay soil (Kavana, personal observation). *Panicum maximum* is a common grass in the eastern part of Tanzania and it is often associated with Bothriochloa in abandoned sisal farms in the coastal areas (Kavana, personal observation). The Panicum-Hyparrhenia is recognized as a region along the Coast

**Figure 3.** *Mixed plant species in open wooded grassland of western Serengeti, Tanzania.*

### *Interaction of Grassland Ecosystem with Livelihood and Wildlife Sustainability: Tanzanian… DOI: http://dx.doi.org/10.5772/intechopen.101343*

northwards from Tanzania, Kenya, and finally into Somalia [15]. *P. maximum* is more typical grass of shady places in the foothills of Mountain ranges up to 2000 m.a.s.l. and is a pioneer grass that comes in after clearing and cultivating the lowland forest [15]. The Sporobolus-dominated grasslands usually exist on seasonally dry alkaline soils and are not destroyed by fire [16]. Therefore, grassland habitats provide valuable pastures in semi-arid areas of Tanzania where *Sporobolus pyramidalis*, *S. marginatus*, *S. ioclados* and *S. cordofanus* sometimes occur in association. *S. consimilis* and *S. spicatus* association occurs as a mosaic along the lakeshore for example along Lake Burunge in northern Tanzania [16].

In southern miombo woodlands of Tanzania, *T. triandra* is a dominant grass and widespread and occurs at different topographic positions [17]. On deeper Plateau soils tall grasses of *Hyperthelia dissoluta* and *Andropogon gayanus* of about 2 m dominate. On hill slopes, *Hyparrhenia newtonii* and *Andropogon schirensis* with a height of about 1.2–1.4 m is very frequently present. On leached soils grasses are mostly 0.6–0.8 m, *Aristida adscensionis* is primarily dominant [17].

In the western miombo woodlands of Tanzania, there are extensive, continuous woodlands interspersed with seasonally inundated grasslands known as "mbuga" in the Kiswahili language (**Figure 4**).

According to an unpublished report by Kavana and Kakengi [18] they observed that common grasses in seasonally flooded plains include *Cynodon dactylon, C. articularis, C. cyperoides, C. difformis, C. dives, C. esculantus, C. involucratus, Cyperus papyrus, C. rotundus, Phragmates mauritianus, Pennisetum purpureum, Sporobolus spp, Echinochloa pyramidalis* and *Oryza longistaminata* (**Figure 5**).

In settlement areas where miombo woodlands are cleared for agricultural and grazing lands, the common grasses include *Panicum maximum, P. repens, Panicum trichocladum, P. trichocladum, Pennisetum polystachyon, P. polystachyon, Rhynchelytrum repens, Setaria homonyma, S. sphacelata, Sporobolus africanus, S. fimbriatus, S. ioclados, Sporobolus pyramidalis, S. sanguineus, Urochloa decumbents* and *U. echinolaenoides* (**Figure 6**)*.*

Some characteristic mosaic grassland occurs proximal to Lake Rukwa where dominant grass species stand a change with soil alkalinity progressing towards the lake [19]. Cymbopogon begins in less alkaline soil (pH 7.5–8.5) followed by Hyparrhenia, Chloris, Cynodon, *Sporobolus robustus*, Echinochloa, Cyperus, Diplachne, and *Sporobolus spicatus* at pH 9.5–11 [19]. Therefore, Tanzania is diverse and influenced by climatic conditions, soil, and anthropogenic activities [8].

**Figure 4.**

*Typical characteristics of grassland in Ugalla ecosystem assessed by researchers from Tanzania Wildlife Research Institute.*

#### **Figure 5.**

*Seasonally flooded grassland plains of Western Serengeti were assessed by researchers from Tanzania Wildlife Research Institution.*

**Figure 6.** *Robust Pennisetum polystachyon and Rhynchelytrum repens in agricultural land, western Tanzania.*
