Plant-Animal Interactions

Plant-Animal Interactions Teacher guide [Recommended year 9 - 12] Education @ Adelaide Botanic Garden Bookings All visits to the Botanic Gardens should be booked as part of risk management. Self-Managed Excursions Booking online: http://www.botanic.sa.edu.au/index.php/book-online Booking by email: [email protected] booking form here Booking by phone: 08 8222 9311 Education Manager discussions and bookings ph: 08 8222 9344 or email: [email protected] Guidelines when in the Garden Students must be supervised at all times while in the Garden. Before starting your walk please remind your group that: • Gardens are peaceful places for people to relax and enjoy. • Walking slowly and talking quietly ensures everybody and everything will enjoy the gardens. • Plants are fragile, touch them gently. • Flowers, leaves, bark, seeds etc. growing on plants or lying on the ground are there for all to enjoy. When you have finished with plant material found on the ground always return it to the garden. • Keeping to paths and not walking on beds or borders avoids damage to plants. Risk Management • Water: The garden has a number of open water bodies and requires close supervision by teachers and supervising adults. • Student ratio: Adult to student ratio is recommended at 1:10, for Early years and Junior primary this should be lower. • Weather: Excursions at the Adelaide Botanic Garden are outdoors so sun protection is required, insect repellent at certain times of the year is recommended. Light showers are not an issue in the gardens and at time enhances the experience. There are a number of sheltered areas throughout the garden and raincoats are preferred to umbrellas. • Washing: After working in the wetland or handling plant material hands should be thoroughly washed particularly before eating. • Toilets: There are 5 groups of public toilets across the Garden as indicated on the maps. Copyright: ©2015 The State of South Australia, Department for Education and Child Development and the Botanic Gardens of South Australia. This publication is protected by copyright. It may be reproduced by South Australian teachers for use with their students. Contents • Purpose and key idea of the trail • Australian Curriculum Connections • Before the excursion • After the excursion • Map • Acknowledgements • Teacher background information Purpose and key idea of the trail Purpose This trail uses plants in the Adelaide Botanic Garden and in the Museum of Economic Botany to introduce students to the diverse ways in which plants and animals rely on each other and also to illustrate the value of conserving interactions between species when we seek to conserve biodiversity. The trail is designed for secondary school students. Through discussion and keen observation, the students are encouraged to gain an appreciation of process and outcomes for different plant-animal interactions; • How do they operate? • Why are they important for the environment and people? • Why are they under threat? Context Plant-Animal interactions in Context Biodiversity is a word that has become familiar to many people, but what does it really entail? The answer is a lot! Biodiversity is the abundance and variety of living organisms, the diversity of ecosystems in which they live and the characteristics of individual organisms. These organisms or species form distinct communities. A species interacts with, and relies on, other organisms within its own community for food and services. These interactions between species are what facilitate the self-preservation of biodiversity. We live in a time in which rates of extinction are very high. Species are being lost either locally or forever, most often due to the activities of humans. The extinction of a species means that the interactions it has with other species are also lost. This can lead to further degradation of biodiversity. The conservation of biodiversity typically involves preserving individual species and communities. However, there is also an increasing emphasis on conserving interactions between plants and animals to maintain the resilience of ecosystems and also to maintain the products and services they provide us. Key Concepts Key concepts that may be linked to the Australian Curriculum include: • Biodiversity and Conservation • Food production and Sustainability • Environmental Science Time: Allow about 2 hours for this session. Australian Curriculum Connections General capabilities • Critical and creative thinking Learning Areas Year 9 Science Multicellular organisms rely on coordinated and interdependent internal systems to respond to changes to their environment (ACSSU175) Ecosystems consist of communities of interdependent organisms and abiotic components of the environment; matter and energy flow through these systems (ACSSU176) Year 10 Science Plan, select and use appropriate investigation methods, including field work and laboratory experimentation, to collect reliable data; assess risk and address ethical issues associated with these methods (ACSIS199) Before the excursion Background Discussions: The trail introduces students to some common plant-animal interactions including herbivory, seed dispersal and pollination. SEED DISPERSAL occurs when seeds move away from their parent plant. Plants often use animals to assist the further spread of their seed by providing the animals with food attached to the seeds. Such dispersal systems are considered to be beneficial to both the plant and the animal. The animals benefit from the food, and the seeds that are dispersed can have a better chance of growing into a new adult plant. Three types of seed dispersal are introduced. • Myrmecochory means seed dispersal by ants. Many plant species, particularly in Australia and South Africa,produce seeds that bear ant-attracting appendages called elaiosomes. The elaiosomes mimic the smell and composition of dead insects, so the ants do not realise that they are also collecting a seed.Ants tend to disperse such seeds to their nest sites where the elaiosome is eaten and the seed is discarded either within the nest or on the ground nearby. The plants can benefit from having their seed dispersed by ants in several ways. For example, seeds dispersed away from parent plants,where they may suffer competition for light and nutrients,may have a better chance of surviving as seedlings. Seeds taken into an ant nest can be protected from animals that eat seeds, such as rodents, or can be protected from bush fires. • Seed dispersal by scatter-hoarding animalsoccurs when animals collect seeds and bury them in the hope of finding and eating them later. Although scatter-hoarding animals can eat many of the seeds they hoard, they do lose some, and these lost seeds are essentially planted in the ground, away from the parent plants where seedlings can have a better chance of establishing. • Endozoochoryoccurs when animals eat fleshy fruits and in doing so, swallow the seeds. The seeds of the endozoochorous plants have protective seed coats so that the seeds can survive being ingested by seed- dispersing animals. The seeds are then spread unharmed to new areas in the animals’ scats. HERBIVORY is when plants are eaten by animals. Eating plants is not simply a matter of finding any plant and having a meal because plants have developed ways of defending themselves. Two types of anti-herbivore defences used by plants are introduced here. • Chemical defenceis a type of defence whereby plants produce toxic or distasteful chemicals in their leaves to deter animals from eating them. Some animals, particularly insects, have developed a tolerance to certain plant chemicals and specialise on eating those plants. • Ant defenceis a type of defence whereby plants use ants as ‘bodyguards’to deter herbivorous insects from eating their leaves. Most commonly, the plants entice ants to forage on their leaves by providing them with nectar. Nectar is produced by specialised glands called ‘extra-floral nectaries’. While foraging on the plants, ants can attack or scare off herbivorous insects. This relationship is mutualistic as the ants benefit from the nectar and the plants benefit from reduced herbivory. POLLINATIONis an essential step in the sexual reproduction of flowering plants. It occurs when pollen is moved between the male and female parts of flowers and results in the development of new seeds and fruit. Plants often use highly mobile animals such as birds and insects to move their pollen between flowers. For their pollination services, animals are most often rewarded with nectar. The colour and structure of flowers can indicate what type of animals visit the plant and successfully pollinate the flowers. Useful General References Herrera, C. M. and Pellmyr, O. (editors). (2002). Plant-Animal Interactions: an Evolutionary Approach. Blackwell Publishing. Proctor, M.C. F., Peter, Y and Andrew, L. (1996).Natural History of Pollination. Timber Press. Simpson, B. B. and Conner-Ogorzaly, M. (2001).Economic Botany: Plants in Our World.McGraw-Hill. Willmer, P. (2011). Pollination and Floral Ecology.Princeton University Press. Aussie Bee website: www.aussiebee.com.au See Teacher’s Guide for additional web links. Text Books. Knox, B., Ladiges, P., Evens, B. and Saint, R. Biology: An Australian Focus.Chapters – ‘Plants (section on flowering plants)’,‘Living in communities’ and ‘Human Impacts’. McGraw Hill. Campbell, N. A. and Reece, J. B. Biology.Chapters – ‘Community Ecology’ and ‘Conservation Biology and Restoration Ecology’. Benjamin Cummings. Acknowledgments

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