Introduction

The built environment as a part of the physical environment and surroundings encompassing buildings, spaces, constructed elements of the environment created or modified by man. Man has always been known to create amenities to meet various needs (Fadamiro and Atolagbe, 2006).  These amenities according to Bartuska (2011) are intended to serve human needs, want and values. However, in serving mans’ needs, Pearce and Vanegas (2002) noted that these amenities over time create positive and negative impacts that may not be immediately noticeable and whose collective effects need to be minimized in order to meet the needs of man in the present without limiting the ability of future generation in meeting their own needs. A built environment therefore, must be able to provide a physical, social and psychological environment in harmony with the human behavior. In order to improve and not impact adversely on the present or future generations, green areas are created through landscaping in order to improve the visual perceptions, aesthetics and health of the individual.

There is a strong public interest in creating pleasant open spaces, and in this sense, thermal comfort is as important as acoustic or visual comfort. The use of open spaces is influenced by the microclimatic conditions provided, whereas microclimate and thermal perception definitely depend on urban design and show a high temporal and spatial variation. The outdoor thermal environment, is impacted by the built environment, through anthropogenic heat, ground surface covering (Lin et al., 2010), evaporation and evapo-transpiration of plants (Robitu et al., 2006), and shading by trees or constructed objects (Lin et al., 2010).  There is a strong public interest in the quality of open urban spaces that can contribute to the quality of life within cities. However, there is a significant lack of information on comfort conditions in outdoor spaces (Dimoudi and Nikolopoulou, 2003).

In times of excessive heat, it is important to maximize the cooling potential for people. Trees are important as they can be used effectively to improve radiant conditions (Figure 1). Vegetation has a low heat capacity and uses a large proportion of the received radiation resulting from the surface below the leaves being cooler. However, as tree canopies are elevated, they not only cool the surface in shade, but allow people shelter from the sun. This shelter creates cool oases where a person feeling heat stress can shelter from the direct short-wave radiation of the sun and improve their thermal comfort (Georgi and Dimitriou, 2010).

Figure 1 The impact of the radiation reduction provided by trees upon the human radiant energy balance (Georgi and Dimitriou, 2010)

Aim and objectives of the study

The main objective of the study is to determine the effect of trees, greens in open spaces on the behavioural and social perceptions of both staff and students;

Specific Objectives

The set objectives are to:

Assess the Behavioural and Social Perception of Staff and Students about the University Landscape

 Assess the Thermal Comfort from Trees, greens in Open space

Material and Methods

The study was conducted within the university campus of the Federal University of Technology (F.U.T), Akure, Ondo State, which lies between longitudes 7⁰E and 7⁰45¹E, and latitudes 6⁰N and 7⁰N of the equator in Nigeria. The Federal University of Technology, Akure has a population of over 10,000 students and staff.

Snow balling technique was used to select 90 respondents across the University including staff and students. A well structured interview schedule was used to collect data from selected respondents. Data obtained from the study was analyzed using descriptive statistics such as mean (µ) and percentages.

Results and Discussion               

Socio economic characteristics of respondents

Majority (59.1%) of the respondents’ were male, while 47.7% of the respondents were between age brackets of 21 and 30 years of age (Table 1). This implies that both post graduates students and members of academics staff were young adults that take out time to enjoy and appreciate the benefit of greening. The study showed further that a higher proportion (36.4%) were academic staff.    

Table 1 Socio economic characteristics

Green consciousness

In Figure 2, 97.7% of respondents were aware of the effect of environmental quality and over 90% of them were aware of greens and open spaces within the university environment. Looking at the socio-economic characteristics, it was observed that those within the middle age among staff and students utilize the greening within the university and were aware of the impact and benefit of greens. This they attributed to the fact that taking out time to relax is really a good thing to do, and that it helps to contribute to their healthy living.

Figure 2 Level of awareness of greens and open spaces

Respondent perception of the University landscape

Table 2 showed respondents’ perception of the University landscape. 48.9% of the respondents’ agrees that the university is beautifully landscaped which in conclusion (µ=4.14) of the respondent agreed to the statement while 80.2% of respondent strongly asserted that, good landscaping contributes to the serenity of the environment (µ= 4.78). This is in agreement with Habib and Ismaila, (2008) assertion that provision of quality living and learning sets is crucial for staff and student in the University campuses.

Table 2 Respondents’ perception of the university landscape

Other respondents’ perception about the university landscape include; 50% of the respondents agreed that there were adequate green spaces within the university environment (µ=3.88), open spaces serve as reading location for students (µ=3.80) and that there are adequate trees to provide shade within the university.  The quality of an environment is dependent on its landscaping, this can be attributed to the unity and harmony of landscape principle incorporated into the element of landscape whereby leading to a healthy and organized social and cultural lives of both staff and students, this according to respondent perception, 61.7 % agreed that the university landscape improved environmental quality. This is in agreement with the findings of Tzoulas (2007), that on campus, greenery promotes health. This means greenery and open spaces are not just amenities but also a means of connecting the ecological systems that conserve air, water, microclimate, energy resources and enriches human quality of life. The perception of students’ revealed that 40.9 % of them strongly agreed that open spaces serves as reading location. This is in agreement to Tolley (1996) that, University with a vast green area is a conducive place of study.

Respondent and preferred spaces

The result in Figure 3 showed that 90.9% of respondents love to relax and prefers to take out time to relax under trees with green. This is in agreement with Toccolini (2006) that green area are network of greening and interconnected open spaces formed by tree-streets, waterways and drainage ways around and between urban areas, at all spatial scales where people can use for work or study . Campus green area is composed of tree-street, walkways (Benedine and Adamu, 2007). Green area allows campus residents to undergo their daily activities such as walking, jogging, experiencing nature, watching people, meeting friends, displaying artworks and many more.

Figure 3 Showing where respondent love to relax

Influence of weather on respondent.

Preference to different seasons of the year by people as shown in Figure 4 vary on the basis of respondents’ view; from a bio-aspect, agro-aspect, aviation-aspect e.t.c. The two seasons in Nigeria as defined by (Omotosho, 1983 and Adefolalu, 1984) are the summer season popularly known as rainy season (which is dominated by ‘warm and moist’ south-west monsoon flow from the Atlantic ocean) and winter season also known as dry season (dominated by ‘cold and dry’ north-east trade wind from the Sahara desert). Having a good idea of weather helps to have a better understanding of the physiological aspect of thermal sensation, it is generally recognized that heat gained or lost by the body to its environment is directly related to the temperature of the surroundings, humidity, wind velocity, amount of radiation within that environment and type of activity carried out as shown in Figure 5.

Figure 4 Showing the concept of weather

Figure 5 Effect of weather parameters on respondent

Respondent perception of green space

The result from Table 3 showed that 52.3% of the respondent moderately enjoy the comfort of green spaces which could be compared to the comfort derived from sitting or standing under a tree to when not sitting or standing under a tree. 40.7% asserted that green spaces can act as a place of comfort while 48.8 % asserted that green space contributes to good health. This can be attributed to the fact that the radiant energy reduction made by a tree will vary depending on the tree canopy size and density, but as a result of tree shade, a person radiates more energy away than he receive resulting in feeling cooler (Georgi and Dimitriou, 2010). In addition to the reduced solar energy, the built surfaces under shade will have lower temperatures and further energy can be lost to these surfaces, furthering the cooling value.

Table 3 Respondents’ perception of green space

Shading from trees can act to cool the atmosphere below by simply intercepting solar radiation. Vegetation and the presence of open green spaces can also change the surface roughness of the landscape, which may affect air movements and, in turn, local temperatures. Water in the leaf is vaporized and released through the stomata, this release of vapour is known as evapo-transpiration and this not only uses the received energy, but also the water vapour released which “warms the air less” resulting in cooler air temperatures around the area of vegetation (Dimoudi and Nikolopoulou, 2003, Gill, 2006).

At longwave radiation levels, leaves absorb and emit longwave radiation efficiently and are considered almost perfect full radiators (0.94 ≤ ε ≤ 0.99) and by emitting heat to the atmosphere and through efficient convective transfer leaves maintain low temperatures (Kuttler, 2008). The reason stated above, and the fact that they have a large surface area compare to their mass results in them being effective heat exchangers, but poor heat store (Kuttler, 2008). The low heat capacity results in very little energy being stored for re-radiation or heating through convection (sensible heat) and much of the received solar energy is used for transpiration (latent heat), cooling the surrounding air temperature. The ratio of sensible heat and latent heat varies due to some factors, such as air temperature and water availability, and is quantified by the Bowen ratio (Monteith and Unsworth, 1990).

Health benefits derived from greening

In Figure 6, 23%  and 20% of respondents’ are relieved of stressed and fatigue respectively, when people are exposed to natural environment, the level of stress decreased rapidly compared to people who were exposed to polluted environment, their stress level remains high (Heidt and Neef, 2008). This is a clear indication that urban green spaces can increase the physical and psychological well-being of urban citizens. The improvements in air quality due to vegetation has a positive impact on physical health such as decreased illness. The connection between people and nature is important for everyday enjoyment, work productivity and general mental health (Grahn and Stigsodotter, 2003). At the level of organization, Westphal (2003), reported that workers experience greater productivity when they have a view of green space from their place of work, and their supervisors also attest to their productivity.

Figure 6 Various human healths derived from greening

Conclusion

The study has established that green spaces are tools for networking between students and staff; the comfortable and pleasant settings provided also enhance community integration. Green areas on campus also offer an opportunity to preserve the disappearing green spaces due to physical development. Over the years, it is anticipated that universities will continue to add new buildings and facilities on their campuses to accommodate more students and staff. Each year with the enrolment of new students; more spaces will be needed to build hostels, new schools for new courses, road signage for managing traffic flow, as well as parking spaces. Hence, the green network which connects one cluster of buildings and spaces on campus to another will provide shade and pleasant conditions that facilitates users’ interaction with ease.

There is a clear indication therefore that greening plays an important role in keeping campus microclimate comfortable thereby encouraging outdoor activities.

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