1. Today we are covering from the specification:

2. What is an agricultural ecosystem? Animals and plants used to produce food for humans. Aims to increase productivity – how?

3. What is productivity? Rate at which useful biomass is produced. Plants produce new biomass using… light energy. Animals produce new biomass using… chemical energy from plants/animals

4. What is productivity? The rate at which organisms assimilate energy taken in is called gross production. Units – energy/area/time (kJm -2 year -1 ) Organisms use some of the new biomass in respiration – what’s left is the net production. Net Productivity = Gross productivity – Respiratory loss

5. 5 Agricultural Productivity Net Productivity = Gross productivity – Respiratory loss Similar to a business… Net profit = Gross Profit – Operating Costs How can agricultural productivity be increased?

6. 6 Task – Agricultural Productivity Create a 10-15 minute presentation on one of the topics below. For each one, include: What it is; How it increases productivity; What ethical/environmental issues can it lead to? Produce a handout for the rest of the class – it could include notes, fill-in-the-gaps, questions etc.. The use of natural and artificial fertilisers. Intensive rearing of livestock. The use of pesticides (chemical and biological) and integrated pest control. Email/give me a copy of the handout by the end of the lesson on Tuesday. Presentations will be on Thursday 16 th October.

7. 7 Agricultural Ecosystem Q. What is the ideal Agricultural “ecosystem” for the farmer? A. Monocultures of domesticated plants or animals. Q. Why do some argue that being a vegetarian is ecologically better. A. Less energy is lost.

8. Agricultural Vs. Natural Ecosystems 8 NaturalAgricultural Solar energy onlySolar + labour + fuels Lower productivityHigher productivity Higher species diversityLess species diversity More genetic diversity within a species Less genetic diversity within a species Nutrients cycle within ecosystem Nutrients added e.g. fertiliser Natural population limitsPopulations managed e.g. planting, pesticides Climax communityInterrupted/managed community

9. Agricultural Ecosystems About how agricultural ecosystems differ from natural ones WAL: All Most Some What is an agricultural ecosystem? How do natural and agricultural ecosystems differ? What is meant by productivity? How is net productivity calculated?

10. What is the difference between a natural and agricultural ecosystem? Energy input, productivity, diversity, population, solar, food, climax community, limiting factor, yield, ecosystem