Nutrient cycles

1. Nutrient cycles

2. The nitrogen cycle

5. Inputs of nutrients : • Precipitation & dry deposition • Weathering of bedrock • [Artificial supplements]

6. Three possible stores : • Soil • Leaf litter • Biomass

7. Outputs of nutrients : • Runoff • Leaching • [Human removal]

8. Where are the nutrients stored in an ecosystem? • the answer varies from one ecosystem to another • dependent on : • temperature • precipitation • vegetation type

9. Taiga

10. litter is main store (needles) • little transfer between stores Boreal forest (taiga)

11. Prairies

12. Rainforest

13. biomass is main store • rapid transfer between stores and environment Tropical rain forest

14. Deciduous

15. balance between stores • moderate transfers between stores Temperate deciduous forest

16. Cation Exchange

17. Human Impacts • Deforestation • Afforestation • Fertilizer (Peds) • Eutrophication • Liming • Acid Rain

18. Bradfield Wood Suffolk Bradfield Woods National Nature Reserve is a working wood that has been under continuous traditional management since 1252, supplying local needs for firewood and hazel products. One of Britain’s finest ancient woodlands the site is a glorious haven for wildlife. The range in soil types from acid to alkaline explains the impressive variety of plants that stood at 370 at the last count.

19. Bradfield Wood Suffolk Bradfield Woods: In the middle ages the wood was in the ownership of the Abbey of Bury St. Edmunds who managed the area under a coppicing with standards regime which is still in use today. Material from the wood is still used for thatching, tool handles, rustic poles, hurdle making and firewood, some of the giant ash coppice stools date back to the Middle Ages. In the visitor centre, open on Sundays and Bank Holidays, there is more of the history of the wood, its management and general information about the wildlife that can be seen

20. Bradfield Wood Suffolk Bradfield Woods: In the middle ages the wood was in the ownership of the Abbey of Bury St. Edmunds who managed the area under a coppicing with standards regime which is still in use today. Material from the wood is still used for thatching, tool handles, rustic poles, hurdle making and firewood, some of the giant ash coppice stools date back to the Middle Ages. In the visitor centre, open on Sundays and Bank Holidays, there is more of the history of the wood, its management and general information about the wildlife that can be seen

21. Bradfield Wood Suffolk

22. Highgate Wood (North London)

23. Highgate Wood (North London)

24. Highgate Wood (North London)

25. Soils • Soil Profile • Horizons • Podsolisation • Salinisation • Eluviation • Illuviated

28. Precipitation> Evapotranspiration Podsol Bases are LEACHED DOWN SOLUBLE bases Mg and Ca washed down BY ELUVIATION MOR HUMUS pH5 decomposition RELEASE HUMIC ACIDS (CHELATING AGENTS) STRUCTURELESS HUMIC ACIDS ATTACK IRON AND ALUMINIUM FROM THE CLAY LIMITED EARTHWORM activity due to acidic Conditions. DISTINCTIVE LAYERS ORANGE ILLUVIAL ALUMINIUM AND IRON PAN

29. Brown Earth

30. Rendzina

31. Gley

32. Plant Succession

33. Define the following terms • Plant Succession or Sere • Xerosere • Halosere • Psammosere • Primary succession • Pioneer community • Xerophytic Environment • Autogenic Succession • Legumes • Climatic Climax Community • Allogenic Successions

34. Plant Succession • (i). Plant Succession  • Succession is a directional non-seasonal cumulative change in the types of plantspecies that occupy a given area through time. • It involves the processes of colonization, establishment, and extinction which act on the participating plant species. • Most successions contain a number of stages that can be recognized by the collection of species that dominate at that point in the succession. • Succession begin when an area is made partially or completely devoid of vegetation because of a disturbance. Some common mechanisms of disturbance are fires, wind storms, volcanic eruptions, logging, climate change, severe flooding, disease, and pest infestation. • Succession stops when species composition changes no longer occur with time, and this community is said to be a climax community.

35. Braunton Burrows • Sand Dune Succession

36. Location

37. Embryo Dunes What can you see in the photo?

38. Yellow or Fore Dunes How does this differ from the embryo dunes?

39. Grey Dunes • The grey dunes are much more stable and mosses and lichens fill the few remaining spaces between plants so that vegetation cover may reach 100%. • Marram grass becomes less common and appears now in isolated patches. Red fescue, sand sedge, sea spurge begin to dominate. Small shrubs (brambles, gorse, buckthorn) appear for the first time. • Environmental conditions 50-100 metres from the sea are much more friendly. There is shelter from the harshest winds, humus is beginning to darken the surface layers and a true soil begins to form. • Soil pH is increasingly acid and heathers may take advantage of the acid conditions. Water content is still low and plants have to search for water with their spreading root systems. • These large dunes are commonly 10 metres in height and wider than those dunes nearer the shore.

40. Define these terms • Subclimax community (e.g. avalanche) • Secondary succession • Subsere communities (rainforest + indigenous humans + back to rainforest)) • Plagioclimax community (Heathland)