**4. Grasslands**

Grassland is an area where various grasses dominate. Vegetation in grassland will grow no taller than the height of a shrub nor a tree. Little do people know that grasslands are one of the major ecosystems that covers close to one-third of Earth's terrestrial surface [6, 7]. In the last century, there is a decline in grasslands area worldwide to convert for arable land for production of animal feed crops and conversely, lack of management and abandonment [8]. Grasslands have been categorised as natural, semi-natural and improved grasslands [6, 9]. Natural grasslands are those that have been formed through processes that are related to the climate, fire and wildlife grazing. Semi-natural grasslands are those with human interventions. Scheduled grazing and hay-cutting are required for maintenance. Lastly, improved grasslands are pastures from ploughing and sowing agricultural varieties or non-native grasses with production value (**Figure 2**).

Grasslands across the globe are managed for a variety of purposes. They are valued for basic goods such as timber and water. They also provide forage, fishes and wildlife, and recreation resources. Grassland is a functional landscape that provides feed for grazing livestock. The landscape provided by the grassland has

#### **Figure 2.**

*Differences in richness and ecological processes were larger between the two perennial grasslands and maize than between prairie and switchgrass. Standardised effect sizes (Hedge's D) are shown for differences in richness and key ecological processes between grasslands and maize (A and C) (effect is difference between average of the two grasslands and maize) and prairie compared with switchgrass (B and D). Error bars show 98% confidence intervals. Asterisks indicate statistical significance at* α *= 0.02. Courtesy of Werling et al. [10].*


*a Includes 110 virus species of the genus Potyvirus, family Potyviridae.*

*b Virus species of the genus Begomovirus, family Geminiviridae.*

*c These are all tenuiviruses that have multiple shapes.*

*d These viruses probably have insect vectors.*

*Courtesy of Hogenbout et al.*

#### **Table 1.**

*In Hogenbout et al. () study, they have discovered the types of genome that affects the diseases of grassland. The table then further explains that types of virus each insect group have been found as vector. However, this information may be limited to the area of experiment conducted and not in other continents [11].*

often been perceived as free and limitless. The table below illustrated that the increase in plant richness will increased pollinators and diversity in the grasslands. With the increase in biodiversity, there was also an increase in pest-egg removal by the arthropod predator. Aphid pressure that is present in a grasslands have also decreased. All these meant that a healthy and well diversified grassland is able to strive and continue to prove various services indefinitely. This has highlighted the importance to conserve and improve grasslands health (**Table 1**).

The climate of grassland will be ideal for the growth of grasses only as low precipitation rate is not sufficient to sustain woody plants. Other maintaining factors of grasslands are fires and grazing animals. Grasses are well adapted to grow back after a fire as they have a complex root system and a resilient physiology. Grasses need not grow by seeds. Different part of the world will have different grassland climates. Therefore, they are differentiated by the Berkeley Biome Group.

With reference to the Berkeley Biome group, grasslands are categorised into two main types. These two types are differentiated according to their climate – tropical and temperate. Grasslands are sensitive to the change in climate as they have a strong seasonal climate. This suggests the possible changes that may occur to the characteristics of the grassland with long term exposure to climate changes. Other evidence also supports the hypothesis as there is a phenological and vegetation

#### *Earth's Energy Budget Impact on Grassland Diseases DOI: http://dx.doi.org/10.5772/intechopen.99971*

shifts1 even before grasslands were impacted by climate change. Grasslands have provided a regulating services by providing climate regulation, carbon sequestration, erosion control, water regulation, air quality regulation, soil formation, pest control, waste treatment and pollination services. These natural environmental services are essential to keep the Earth's energy balance.

Climate change have since impact grasslands through increased seasonal, annual, minimum, and maximum temperature and the change in precipitation patterns [12]. Depending on the location of grassland, the climatic experiences can vary and theses variations include, increased temperatures, reduced rainfall and prolonged periods of drought. Grasslands are often bordered by forests, deserts seas and mountains. The change in earth's energy budget then have a vegetation shifts of either having rainforest encroaching into savanna and arid deserts being projected into arid grassland ecosystem. The slightest change in temperature, precipitation could alter the distribution, composition and the abundance of species in grassland. This would then result in the shift of products and services being provided. With the change in energy can also affect the geographical and elevational boundaries [13].
