L7 Terrariums PDF

Terrariums Objectives: Work cooperatively in a small group to build a terrarium Understand the key components of a terrarium and their functions Understand the key reactions and processes that occur in a terrarium Understand why a terrarium is a self-sustaining closed system  A terra...

Terrariums Objectives: Work cooperatively in a small group to build a terrarium Understand the key components of a terrarium and their functions Understand the key reactions and processes that occur in a terrarium Understand why a terrarium is a self-sustaining closed system  A terrarium is a self-sustaining ecosystem, with biotic and abiotic components. Even if it is sealed, so that it is a closed system, the biotic components can stay alive because of nutrient cycling and gas exchange.  Materials: Dried Moss, Worms, Plants, Pebbles, Soil, Charcoal 2 large glass salad bowls, water Planning the terrarium design 1. What order do you think the materials should be added in to the salad bowl and why? 2. Do you think the size of each layer matters? 3. What do you think the role of each component is? Pebbles  The pebbles are an important drainage layer that prevent water accumulating around the plant roots which can lead to the growth of mould and rotting of the plant Charcoal  The main benefit of adding charcoal to a terrarium is toxin removal. Charcoal absorbs chemicals in the soil, water and air that can build up inside your terrarium over time. A layer of charcoal also helps form a drainage layer. Drainage layers help ensure excess water doesn't stay in the soil and cause root rot and mould. Sphagnum Moss (Dried)  Dried sphagnum moss increases the soil's capacity to hold water and nutrients. The moss layer helps keep the soil moist without being overly wet A layer of sphagnum moss on top of the pebbles also helps keep the soil from mixing into the pebbles. Soil (potting mix) Soil Soil provides a structure for the plant roots to grow. Soil holds water for the plants Soil contains nutrients/minerals like nitrogen needed for the plants to be healthy Soil contains bacteria and fungi (decomposers) which help to recycle nutrients Worms Worms Worms are detritivores and beneficial in helping to break down decaying matter and aerate the soil. Millipedes and springtails are also useful Springtails can help combat and eliminate the most common terrarium problem: mould. They feed off of mould and dead vegetation and therefore make for a great ‘clean-up crew’ Millipedes are scavengers that eat decaying wood, leaves, and other undesirables. Plants  The plants should be slow growing and tolerate humid conditions Inspect them for disease before they are placed in the terrarium Water Spritz soil and leaves It is important not over water the terrarium, if it is too moist then this can lead to growth of mould Terrarium Layers: Plants Soil Moss Charcoal Pebbles Method 1. Take your clean empty glass salad bowl 2. Add 500-550g of pebbles to make the first layer 3. Add 100-150g of charcoal to make the second layer 4. Add a third layer of moss with a height of about 3cm 5. Add a fourth layer of soil with a height of about 5cm 6. Add 2 or 3 plants, ensure their roots are embedded into the soil 7. Add 2 or 3 worms into the soil 8. Spray the leaves and soil with water from the spray bottle until they are moist (be careful as overwatering causes mould growth). Pour 10-20ml of water over the soil 9. Balance your second salad bowl on top and tape them together. 10.Place the terrarium on the side benches by a window and wash your hands Water cycle You have studied this in Geography Discuss how and where different aspects of the water cycle are occurring in the terrarium  Evaporation- liquid water in the soil gains enough heat energy to become water vapour in the air Transpiration- water moves up the inside of plants (from roots to leaves through stems), then evaporates out of the leaves Condensation- water vapour in the air cools to form liquid water Precipitation- liquid water falls out of the air and into the soil Infiltration - water soaks down into the soil Carbon cycle There are carbon atoms in living organisms (in their biomass) and in the air (carbon dioxide gas). Discuss how carbon is cycled in a terrarium via the processes of feeding, respiration and photosynthesis- Include 3 stores of carbon: animals, plants and carbon dioxide. Think about how to layout the cycle, where to draw arrows, and what to label the arrows with (processes that move carbon between stores)  Carbon dioxide animals plants Feeding