5.3.2 Populations and Sustainability By Ms Cullen

Should Ms Cullen go to the Galapagos Islands? Or Should Ms Cullen go to the Galapagos Islands?

Learning Objectives To recognise that many different factors will determine population sizes. To explain the significance of limiting factors in determining the final population size. To use the Galapagos Islands as an example of the need for a balance between conservation and ecotourism and to discuss how they can be managed to lessen the impact of human activity on the islands.

Population growth

Population growth in r-strategist species 5

Predator/Prey Relationships

Predator/Prey Relationships Can you explain the graph?

Competition There are two types of competition: Intraspecific competition – this occurs between members of the same species. Interspecific competition – this occurs between members of different species.

Intraspecific competition As population numbers drop, so will competition within a population. Conversely as population numbers rise, so will competition for resources between individuals.

Interspecific competition This can affect both size (abundance) and distribution of populations within an ecosystem.

Allelopathy Allelopathy is when an organism produces one or more biochemicals that influence the germination, growth, survival, and reproduction of other organisms. It is a form of competition because it prevents the plant’s neighbours using the resources in the habitat. These biochemicals are known as allelochemicals and can have beneficial or detrimental effects on the target organisms and the community. Allelochemicals are a subset of secondary metabolites, which are not required for metabolism of the organism that produces them. Allelochemicals with negative allelopathic effects are an important part of plant defense against herbivory.

Allelopathy Allelopathic chemicals can be found in almost any part of the plant; they may be released from roots directly into soil or leached out of leaves or fruit when a plant sheds them. Examples: The black walnut tree releases a chemical called juglone. This inhibits respiration in younger plants. Why do you think this is advantageous? The cereal plant sorghum releases sorgolene through it’s roots, disrupting photosynthesis and respiration in neighbouring plants. Many invasive plants use allelopathy eg spotted knapweed Allelopathy is also known as chemical competition.

Conservation or preservation? What is the difference?

Why do you think we need to conserve species and resources? Brainstorm: Economic reasons Ecological Reasons Aesthetic and Ethical Reasons

Sustainability Successful management of resources leads to sustainability. Sustainability is the management of a resource or system, so that it is replenished at the same rate that it is used. Sustainability has become increasingly important as our world population grows and their is increasing competition for resources. Can you think of examples of sustainability?

Sustainability is……….

Galapagos and tourism

Ecotourism The World Conservation Union and the Ecotourism Society define eco-tourism as “responsible travel to natural areas that conserves the environment and sustains the wellbeing of local people” (Blangy and Wood, 1993).

Human Impact on Galapagos?

Galapagos Islands - ecotourism Threats Increased population Overfishing Tourism Why have these issues become threats? What can be done to limit the impact? Can some of them be advantageous? How would you promote ecotourism and responsible travelling?

Ecosystem Management Case Studies

Ecosystem Management – The Masai Mara National Reserve (MMNR) Savannah ecosystem divided by Mara river Closer to river has fertile woodland and grassland ecosystems MMNR is famous for zebra and wildebeest migrations Named after local nomadic tribe the Masai

Farming in the MMNR Traditionally semi-nomadic farming, where livestock graze depending on climate variation and presence of tse-tse fly. What is the benefit of this method? Local tribes are now prevented from entering the park, limiting grazing to the edges of the reserve What effect do you think increased populations will have had?

Ecotourism in MMNR What needs to be addressed?

Conservation and Research in MMNR MMNR plays an important role in conserving many endangered species. The Black Rhino Diceros bicornis (on IUCN critically endangered list) Why? Numbers declined from 100 in 1972 to a handful of individuals in 1982

Conservation and Research in MMNR Active conservation programme has been set up to address the balance between local people and wildlife The aim is:

Ecosystem Management – The Terai region of Nepal Southern part of Nepal High population density Rich fertile alluvial soil, exploited for agriculture Incredibly biodiverse; sub-tropical areas and thick forest Important source of national income Deforestation has exacerbated effects of monsoon flooding If this continues only isolated pockets of forest will be left

Ecosystem Management – The Terai region of Nepal This area was decreasing by 1.9% in 1990s! 40% of land in Nepal was forested

Ecosystem Management – The Terai region of Nepal National legislation and the formation of local community forestry groups has allowed this to happen, these local networks and businesses can work together to achieve Forestry Stewardship Council (FSC) certification. An internationally recognised reward for sustainable forestry. Successes include: Bengal tiger, indian rhinocerous, sloth bear

Ecosystem Management – The Terai region of Nepal Since 2000 the decline in forest areas has reversed and forest coverage is now increasing  Management strategies for sustainable land use include: Promoting fruit and vegetable growth in hill region to avoid further intensive faming of Terai region Improving irrigation to enhance crop production More than 1 crop is grown on a piece of land each growing season – multiple cropping Growth of nitrogen fixing crops to enhance soil fertility Growing crop varieties resistant to abiotic and biotic challenges through modern biotechnology and genetic engineering Improving fertilisation techniques to enhance crop yields, eg using manure to improve soil Bengal tiger, indian rhinocerous, sloth bear

Ecosystem Management – The Terai region of Nepal Q: Explain how sustainable forestry and agricultural practices are being used in the Terai region to maintain biodiversity, while also meeting the needs of the local population (4 marks) Bengal tiger, indian rhinocerous, sloth bear

Ecosystem Management – Peat Bogs

Ecosystem Management – Peat Bogs In the UK, lowland raised bog is estimated to have decreased by over 90% From 950km 2 to only 60 in last 100 years  Region of wet, decaying vegetation, formed by anaerobic and acid conditions inhibiting decay. Take thousands of years to form Carbon sink Peat can be used as a fuel once dried or as a soil improver to increase acidity and structure of soil Why are they at risk and why is this such a concern?

Why should we conserve peat bogs?

How can we conserve peat bogs? To conserve lowland bogs water levels need to be maintained/restored, strategies to ensure this include: Leave surface of bog undisturbed and wet. Ditches should surround bogs to prevent flooding of neighbouring land. Removal of seedling trees, as trees use huge amounts of water during transpiration and can dry out bogs and prevent growth of bog vegetation. Controlled grazing and/or burning of wetland. Promotes species diversity. Organisations such as RSPB, The Wildlife Trusts and Natural England are working to preserve peat bog ecosystems.

What impact do human activities have in environmentally sensitive areas? - Antarctica

How can we control the effects of human activities in environmentally sensitive areas? - Antarctica Ideas?

How can we control the effects of human activities in environmentally sensitive areas? – Lake District National Park Ideas?

How can we control the effects of human activities in environmentally sensitive areas? – Snowdonia National Park Ideas?

Home study: Sustainability – Research and notes on small and large scale timber production – coppicing, pollarding etc and sustainable fishing. Start with Kerboodle P.639-641. Then find more information, data (especially on fish population numbers) and images off the internet & include refs!