Project-1: Influence of vegetation cover on microclimate

Project-1: Influence of vegetation cover on microclimate

The microclimate in simple term refers to the modified climate of a small area which is different in temporal and spatial scale from the climate of the region. The microclimate is modified by vegetation cover, industrialization, development of human settlement and any other intervention in the land use pattern. Tree plantation restricts incoming radiation and has a cooling impact on the microclimate. Trees also act as shelterbelts and reduce desiccating effect of wind. Vegetation cover greatly modifies the soil environment in long run which is a vital component of the microclimate. Modification of microclimate is the perceptible and immediate effect of anthropogenic intervention in land use system. A basic understanding of microclimate will help the students to conceive the possible impact of land use change.

Objective

1. To understand the microclimate
2. To study the impact of vegetation cover on microclimate
3. To have a comparative study of microclimate under different land use system
The experiment may be divided in two components
(A) Field study - monitoring microclimate of different land use system
(B) Development of workable model to understand the concept of microclimate

Part A: Field study - monitoring microclimate of different land use systems
Methodology
Select different land use systems in the surrounding locality
a) Crop land
b) Barren land
c) Forest land/Orchard
d) Settlement areas and any other typical land use system.
Two simply measurable parameters: temperature and evaporation are selected. This can be improvised by incorporating additional indicators.
• Keep circular leak proof open pan of ½ m diameter and 50 cm depth at the representative place of each land use system. Fill with water up to 30 cm depth. Cover it with wire net.
• Keep the thermometers in suitable places to measure soil temperature, water temperature (of the pan) and air temperature in these sites. Care should be taken to avoid direct radiation on the bulb of the thermometer.
• Record the temperature observations three times daily at early morning (say, 7 am), mid day (say at 12 to 2 pm) and during evening (say, 6 pm) over a period of 4 months at weekly interval.
• Record the depth of water from these pans at weekly interval and add water as per requirement during the period of study
• Collect the soil samples from each site at 10 cm depth 3 days after each rain event. Take the fresh weight (immediately after collection) and again by drying the same sample at 105 0C for 24 hours in an oven. Calculate the moisture content as below -

Soil moisture content = (Fresh soil weight – Dry soil weight)/Dry soil weight
The impact on soil evaporation can only be perceptible if soil types are same because the soil type (textural class) is a major driving factor for water release from soil for evaporation

Important note: It is a group activity. Time synchrony has to be maintained for observations at different field sites. Each student may be assigned one site for diurnal observation.

Relevance:
Note the difference in temperature and evaporation rate from each observation site. These parameters are easily perceptible but important indicators to define a microclimate of a place. Mark, how human intervention changes the microclimate. This will give help the students to understand the microclimate and in broad sense demonstrate how anthropogenic intervention is responsible for modification of the climate on the earth surface.

Part B: Understanding the concept of microclimatic
Materials required
• Earthen pot (6 Nos)
• Seedlings (Fast growing plant depending local suitability)
• Card board & Ply board
• Thermometer (2 Nos)
• Open pan of 20 cm diameter and 5 cm depth
Methodology:
• Take 6 earthen pots. Make a whole at the bottom of each pot.
• Fill the pots with one thin layer of small stones at the bottom and the rest with soil
• Plant one seedling in each pot and water regularly.
• Make two model houses using card board / ply board
• Place one model house in the middle of 6 pots and one house in open area
• Measure the temperature of the roof top of each house (using thermometer) at 15 days interval starting from the date of planting.
• Place the open pan near each model house and keep 2 cm depth of water in each pan. Add water to each pan after drying.
• Note the temperature difference between the two situations
• Note the time required to dry up the water from each pan
Relevance:
This project will give a direct experience to the students about how plantation helps in ameliorating the microclimate. Maintaining the plants from sowing to subsequent growth will induce the association of students with the plants and will help in understanding the concept of microclimatic modification at the same time. Hands-on learning process will be an interesting and effective method.

Note: These two exercises (part-A & part-B) may be considered complimentary to each other