Develops and understanding of Zonation and Succession through a case study of the Garigue ecosystem in the Corbiere range in South East France as part of the Pyrenees. The Garigue is a typical Mediterranean Type ecosystem but its range has been significantly increased historically through human influence. With rural depopulation secondary succession has developed and biodiversity change is occurring. This resource has been created for IB Diploma ESS, but it is also useful for Post 16 Biology and Geography courses. For downloadable versions please visit the four corners education TES webstore

1. Topic 2.4: Biomes, Zonation and Succession
Topic 2: Ecosystems and Ecology

2. Topic 2.4: Biomes, Zonation and Succession
Topic 2: Ecosystems and Ecology
Succession and Zonation in the Pyrenees

3. Topic 2.4: Biomes, Zonation and Succession
Topic 2: Ecosystems and Ecology
Succession and Zonation in the Pyrenees
Part 1- Developing the context: Biomes, Zones and Habitat
distribution

4. Climate determines the type of biome in a given area, although individual ecosystems may vary due to many local abiotic and
biotic factors.
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Main ideas

5. Climate determines the type of biome in a given area, although individual ecosystems may vary due to many local abiotic and
biotic factors.
Succession leads to climax communities that may vary due to random events and interactions over time. This leads to a
pattern of alternative stable states for a given ecosystem.
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Main ideas

6. Climate determines the type of biome in a given area, although individual ecosystems may vary due to many local abiotic and
biotic factors.
Succession leads to climax communities that may vary due to random events and interactions over time. This leads to a
pattern of alternative stable states for a given ecosystem.
Ecosystem stability, succession and biodiversity are intrinsically linked.
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Main ideas

7. France
Pyrenees
The Corbieres
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Found in the Pyrenees
Foothills of the Haute (High) Pyrenees

8. The Corbieres
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Corbieres
France
Pyrenees
Found in the Pyrenees
Foothills of the Haute (High) Pyrenees

9. The Corbieres
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Corbieres
France
Pyrenees
Found in the Pyrenees
Foothills of the Haute (High) Pyrenees
Patch work of fields and woodland
Farmed since Roman times

10. The Corbieres
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Home to the Garigue community

11. The Corbieres
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Home to the Garigue community

12. “Garigue is more or less open shrub community, usually about 50cm high, and rarely growing
above 1m. The dominant dwarf shrubs are often widely spaced, with a considerable amount of
bare, stoney ground between the clumps of shrubs, which, in the hot and very dry summers, gives
the vegetation a very parched appearance. Many species are aromatic, and have small dry
leathery leaves which often curl up in the summer, thus reducing transpiration loss. Some
shrublets are chemically unpalatable to grazing animals, others are very spiny and are thus
protected”
Polunin and Walters (1985)
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
What is Garigue?

13. Community
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

14. Community
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

15. Community
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

16. Community
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

17. Community
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

18. Community
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

19. Describe the adaptations of these plants for resisting herbivory?
Suggest how a herbivore might be adapted to be able to eat these plants?
Community
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

20. Zonation
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Garigue forms a transitional zone
between Forest and Grassland biomes
in the Mediterranean

21. What do we know so far?

22. Forest
Garigue
Grassland

23. Formation
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Clearance of the forest for fuel and
grazing by livestock maintains the
Garigue as a semi natural Climax
community

24. Zonation in the Corbieres
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
For most of
the 20th
Century

25. Zone where evergreen and
deciduous oak are the natural
climax community
Zonation in the Corbieres
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

26. Zone where evergreen and
deciduous oak are the natural
climax community
Zonation in the Corbieres
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

27. Zone where evergreen and
deciduous oak are the natural
climax community
Zonation in the Corbieres
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
FOREST BIOME

28. Zone where evergreen and
deciduous oak are the natural
climax community
Zonation in the Corbieres
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
FOREST BIOME
Zone where dry Mediterranean
grassland is a natural climax
community

29. Zone where evergreen and
deciduous oak are the natural
climax community
Zonation in the Corbieres
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
FOREST BIOME
Zone where dry Mediterranean
grassland is a natural climax
community
GRASSLAND BIOME

30. Zone where evergreen and
deciduous oak are the natural
climax community
Zonation in the Corbieres
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
FOREST BIOME
Zone where dry Mediterranean
grassland is a natural climax
community
GRASSLAND BIOME

31. Zone where evergreen and
deciduous oak are the natural
climax community
Zonation in the Corbieres
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
FOREST BIOME
Zone where dry Mediterranean
grassland is a natural climax
community
GRASSLAND BIOME
Zone where Garigue forms the
natural transition between Forest
and Grassland Biomes

32. Zone where evergreen and
deciduous oak are the natural
climax community
Zonation in the Corbieres
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
FOREST BIOME
Zone where dry Mediterranean
grassland is a natural climax
community
GRASSLAND BIOME
Actual zone where Garigue
forms the natural transition
between Forest and Grassland
Biomes because of the in
fl
uence
of man
FARMING

33. Garigue forms an transitional zone between zones of grassland and forest in the Corbiere range
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Part 1 Summary:

34. Garigue forms an transitional zone between zones of grassland and forest in the Corbiere range
Mediterranean grassland biome is a natural climax community to about 100m or higher where local
conditions allow
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Part 1 Summary:

35. Garigue forms an transitional zone between zones of grassland and forest in the Corbiere range
Mediterranean grassland biome is a natural climax community to about 100m or higher where local
conditions allow
Mediterranean mixed evergreen and deciduous Oak forest biome forms the natural climax
community from sea level to around 1200m
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Part 1 Summary:

36. Garigue forms an transitional zone between zones of grassland and forest in the Corbiere range
Mediterranean grassland biome is a natural climax community to about 100m or higher where local
conditions allow
Mediterranean mixed evergreen and deciduous Oak forest biome forms the natural climax
community from sea level to around 1200m
Distribution of Grassland and Forest communities are controlled by precipitation - where
precipitation is higher forest biome forms.
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Part 1 Summary:

37. Garigue distribution has been extended into the forest zone, through human activity - farming
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Part 1 Summary:

38. Topic 2.4: Biomes, Zonation and Succession
Topic 2: Ecosystems and Ecology
Succession and Zonation in the Pyrenees
Part 2- Why is the Garigue community where it is?

39. Abiotic factors

40. Climate
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Data extracted from https://en.climate-data.org/europe/france/languedoc-roussillon/lezignan-corbieres-66328/

41. Climate
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Temperature
(°C)
0
5
10
15
20
25
30
January
February
March
April
May
June
July
August
September
October
November
December
Avg. Temperature (°C) Min.. Temperature (°C)
Max. Temperature (°C)
Precipitation
(mm)
0
10
20
30
40
50
60
70
80
90
100
January
February
March
April
May
June
July
August
September
October
November
December
Data extracted from https://en.climate-data.org/europe/france/languedoc-roussillon/lezignan-corbieres-66328/

42. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Data extracted from https://en.climate-data.org/europe/france/languedoc-roussillon/lezignan-corbieres-66328/ https://
en.climate-data.org/europe/france/aquitaine/saint-jean-pied-de-port-185285/
Avg.
Temperature
(°C)
0
5
10
15
20
25
January
February
March
April
May
June
July
August
September
October
November
December
LÉZIGNAN-CORBIÈRES SAINT-JEAN-PIED-DE-PORT
Precipitation
/
Rainfall
(mm)
0
20
40
60
80
100
120
140
160
180
200
220
240
January
February
March
April
May
June
July
August
September
October
November
December
LÉZIGNAN-CORBIÈRES SAINT-JEAN-PIED-DE-PORT
Climate Factors

43. Tramontane and Cers winds
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

44. Tramontane and Cers winds
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

45. Tramontane and Cers winds
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

46. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Primary Succession

47. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Primary Succession
Bare rock left after
the retreat of a glacier

48. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Primary Succession
Bare rock left after
the retreat of a glacier
In time mosses and lichens
start to colonise the rock
As they die organic mater
is added to weathered rock
particles making simplesoils

49. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Primary Succession
Bare rock left after
the retreat of a glacier
In time mosses and lichens
start to colonise the rock
As they die organic mater
is added to weathered rock
particles making simplesoils
As the soils develop grasses
and small herbaceous plants
start to grow
More organic mater is added
and roots of plants aid break up
of rock material

50. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Primary Succession
Bare rock left after
the retreat of a glacier
In time mosses and lichens
start to colonise the rock
As they die organic mater
is added to weathered rock
particles making simplesoils
As the soils develop grasses
and small herbaceous plants
start to grow
More organic mater is added
and roots of plants aid break up
of rock material
Deeper soils hold more
water.Small shrubs colonise
these better soils
Nutrient availability increases
More root action

51. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Primary Succession
Bare rock left after
the retreat of a glacier
In time mosses and lichens
start to colonise the rock
As they die organic mater
is added to weathered rock
particles making simplesoils
As the soils develop grasses
and small herbaceous plants
start to grow
More organic mater is added
and roots of plants aid break up
of rock material
Deeper soils hold more
water.Small shrubs colonise
these better soils
Nutrient availability increases
More root action
Eventually trees establish
leading to the development
of a climax community on
mature soils

52. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Primary Succession
Bare rock left after
the retreat of a glacier
In time mosses and lichens
start to colonise the rock
As they die organic mater
is added to weathered rock
particles making simplesoils
As the soils develop grasses
and small herbaceous plants
start to grow
More organic mater is added
and roots of plants aid break up
of rock material
Deeper soils hold more
water.Small shrubs colonise
these better soils
Nutrient availability increases
More root action
Eventually trees establish
leading to the development
of a climax community on
mature soils
TIME

53. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Garigue species naturally appear in the forest community
But are at low density because of competition for light

54. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Where a gap naturally appears
A Garigue like community develops - less competition for light

55. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Human influence
Forest clearance and
grazing creates permanent
gaps

56. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

57. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

58. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Garigue formation

59. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Garigue formation
Formation:
Maintained by grazing and agriculture
Abiotic in fluencies:
Climatic - Warm and dry

60. Biotic community
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

61. Biotic community
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Patchwork of -
Grasses
Thistles
Thorny shrubs
Aromatic flowering plants (herbs)
Topic 2.1 link
How might the biotic
plant community of the
Garigue demonstrate
the concept of the
niche?

62. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Topic 2.1: Revisiting theNiche concept
Niche
A species’ share of a habitat and the resources in it.
An organism’s ecological niche depends not only on where it
lives but on what it does.

63. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Falco pereginus
the sum total of an organism's use of the biotic and
abiotic resources in an environment
Topic 2.1: Revisiting the Niche concept - Competition

64. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Food needed
etc.
Space needed
Climate needed
Falco pereginus
the sum total of an organism's use of the biotic and
abiotic resources in an environment
Topic 2.1: Revisiting the Niche concept - Competition

65. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Topic 2.1: Revisiting the Niche concept
Fundamental niche:
the set of resources a
population is theoretically
capable of using under
ideal conditions
the sum total of an organism's use of the biotic and
abiotic resources in an environment

66. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Topic 2.1: Revisiting the Niche concept
Fundamental niche:
the set of resources a
population is theoretically
capable of using under
ideal conditions
Realised niche:
the resources a population
actually uses
the sum total of an organism's use of the biotic and
abiotic resources in an environment

67. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
The realised niche may
be smaller than the
fundamental niche
because of competition
with other species or
other individuals in the
same population
the sum total of an organism's use of the biotic and
abiotic resources in an environment
Topic 2.1: Revisiting the Niche concept - Competition

68. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
The realised niche may
be smaller than the
fundamental niche
because of competition
with other species or
other individuals in the
same population
Species 2
Species 1
Resource Overlap
Species 2
Species 1
Resource Overlap
the sum total of an organism's use of the biotic and
abiotic resources in an environment
The more competition the smaller the realised niche
Topic 2.1: Revisiting the Niche concept - Competition

69. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
If the competition is too great between species ONE species will
out compete the other
If the competition is too great within a species then the
population could collapse
the sum total of an organism's use of the biotic and
abiotic resources in an environment
Topic 2.1: Revisiting the Niche concept - Competition

70. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Fundamental Niche
of species found in the
Forest community
Fundamental Niche
of species found in the
Garigue community
Fundamental Niche
of species found in the
Grassland community
Topic 2.1: Revisiting the Niche concept - Competition

71. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Topic 2.1: Revisiting the Niche concept - Competition
However there is
competition as Garigue
species are also found in
both the forest and
grassland communities

72. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Topic 2.1: Revisiting the Niche concept - Competition
The realised niche of
species of the Garigue
community when found in
either the forest community
or grassland community
Garigue community species
are out competed for
resources when found in
forests or grasslands
Garigue species are also
found in forest and
grassland communities

73. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Topic 2.1: Revisiting the Niche concept - Competition
Where the Garigue exists as
a natural tradition between
forest and grassland zones,
Garigue species face less
competition

74. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Topic 2.1: Revisiting the Niche concept - Competition
When the forest is cleared
for grazing and the Garigue
that forms is maintained
through grazing

75. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Topic 2.1: Revisiting the Niche concept - Competition
1000m
100m
500m
Forest Community
Grassland Community
Garigue Community
X
Realised niche of Garigue
species without and with
grazing pressure (human
influence)
Limiting factor for Garigue
species competing in the
forest community is light
Removal of the tree cover
opens up opportunity for
Garigue species. Grazing
maintains that opportunity

76. Summary of conditions that allow the development and
maintenance of the Garigue community
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

77. Abiotic conditions

78. Abiotic conditions
Dry Mediterranean climate
Warm summers
Mild winters
Low precipitation
South facing -towards the sun
Steep stoney well drained soils
Biotic conditions
Man
Removal of forest vegetation for
pasture and fuel
Grazing by goats - removes
tree seedlings
Patches of thorny shrubs and
plants - defences against
grazing by sheep and cattle
Aromatic plants (herbs) with
chemical defences against
grazing. e.g. Lavender, Thyme,
Wormwood

79. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Consequences of rural depopulation and changes to farming
in the Garigue on succession

80. Rural
population
as
a
%
of
total
French
population
0
5
10
15
20
25
30
1971
1973
1975
1977
1979
1981
1983
1985
1987
1989
1991
1993
1995
1997
1999
2001
2003
2005
2007
2009
2011
2013
2015
2017
2019
Rural depopulation in France
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

81. 2019
Rural
population
as
a
%
of
total
French
population
0
5
10
15
20
25
30
1971
1973
1975
1977
1979
1981
1983
1985
1987
1989
1991
1993
1995
1997
1999
2001
2003
2005
2007
2009
2011
2013
2015
2017
2019
2019
Rural
population
as
a
%
of
total
French
population
0
5
10
15
20
25
30
1971
1973
1975
1977
1979
1981
1983
1985
1987
1989
1991
1993
1995
1997
1999
2001
2003
2005
2007
2009
2011
2013
2015
2017
2019
Rural depopulation in France
Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

82. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Rural depopulation in France
Between the 1960s and the early 2000s the
number of farms in France fell from over
3,000,000 to less than a 1,000,000

84. Garigue forms within the
zone where Pyrenean
Oak forest would be the
natural climax community
This is a closed canopy
community with a limited
ground layers (flowers
and grasses)

86. Clearance of the forest
by man opens up the
ground layer
Cattle and goats
seasonally graze the
pastures created

88. Removal of goats from
the system and thorny as
well as chemically
unpalatable plants start
to invade
This is an example of
secondary succession
If the
fi
eld layer of the
forest system was very
limited where did the
invading plants come from?

90. Remove the cattle as well
and shrubs, bushes and
tree seedings start to
invade
NB* with only cattle to
graze the pastures of the
garage need to be
cleared by man to remain
shrub free - this is labour
intensive

92. Overtime more shrubs
grow - secondary
succession

94. Eventually tress start to
appear in the system and
less and less pasture is
clear and available for
grazing

96. Without continued
grazing or clearance
eventual the area reverts
to closed forest
This is a problem for
biodiversity!
Biodiversity in the garage is
maintained by goats (and
cattle) grazing the area.
It is a man made system of
high biodiversity
importance

98. Climax mixed evergreen
and deciduous oak forest
cover clearance to provide
grazing and fuel

99. Climax mixed evergreen
and deciduous oak forest
cover clearance to provide
grazing and fuel
Grazing by goats and
cattle maintains an open
Garigue community of low
spiny shrubs and aromatic
flowering plants with
grass patches between

100. Climax mixed evergreen
and deciduous oak forest
cover clearance to provide
grazing and fuel
Grazing by goats and
cattle maintains an open
Garigue community of low
spiny shrubs and aromatic
flowering plants with
grass patches between
Continued grazing by
goats and cattle maintains
the Garigue as a semi-
climax community

101. Climax mixed evergreen
and deciduous oak forest
cover clearance to provide
grazing and fuel
Grazing by goats and
cattle maintains an open
Garigue community of low
spiny shrubs and aromatic
flowering plants with
grass patches between
Reduction in grazing
pressure (herbivory)
because of rural
depopulation and
changing farming
practices, in particular
fewer goat herds allows
more shrubs and tree
saplings to develop
Continued grazing by
goats and cattle maintains
the Garigue as a semi-
climax community

102. Climax mixed evergreen
and deciduous oak forest
cover clearance to provide
grazing and fuel
Grazing by goats and
cattle maintains an open
Garigue community of low
spiny shrubs and aromatic
flowering plants with
grass patches between
Reduction in grazing
pressure (herbivory)
because of rural
depopulation and
changing farming
practices, in particular
fewer goat herds allows
more shrubs and tree
saplings to develop
Tree saplings establish
from the surrounding Oak
forest on higher and
steeper slopes (transport
of matter from
surrounding ecosystems),
reducing amount of
grazing available
Continued grazing by
goats and cattle maintains
the Garigue as a semi-
climax community

103. Climax mixed evergreen
and deciduous oak forest
cover clearance to provide
grazing and fuel
Grazing by goats and
cattle maintains an open
Garigue community of low
spiny shrubs and aromatic
flowering plants with
grass patches between
Reduction in grazing
pressure (herbivory)
because of rural
depopulation and
changing farming
practices, in particular
fewer goat herds allows
more shrubs and tree
saplings to develop
Tree saplings establish
from the surrounding Oak
forest on higher and
steeper slopes (transport
of matter from
surrounding ecosystems),
reducing amount of
grazing available
Continued grazing by
goats and cattle maintains
the Garigue as a semi-
climax community
Secondary succession
leads to re-establishment
of mixed evergreen and
deciduous oak forest
climax community

104. Climax mixed evergreen
and deciduous oak forest
cover clearance to provide
grazing and fuel
Grazing by goats and
cattle maintains an open
Garigue community of low
spiny shrubs and aromatic
flowering plants with
grass patches between
Reduction in grazing
pressure (herbivory)
because of rural
depopulation and
changing farming
practices, in particular
fewer goat herds allows
more shrubs and tree
saplings to develop
Tree saplings establish
from the surrounding Oak
forest on higher and
steeper slopes (transport
of matter from
surrounding ecosystems),
reducing amount of
grazing available
Continued grazing by
goats and cattle maintains
the Garigue as a semi-
climax community
Clearance of current
vegetation to provide
grazing and fuel
Secondary succession
leads to re-establishment
of mixed evergreen and
deciduous oak forest
climax community

105. Climax mixed evergreen
and deciduous oak forest
cover clearance to provide
grazing and fuel
Grazing by goats and
cattle maintains an open
Garigue community of low
spiny shrubs and aromatic
flowering plants with
grass patches between
Reduction in grazing
pressure (herbivory)
because of rural
depopulation and
changing farming
practices, in particular
fewer goat herds allows
more shrubs and tree
saplings to develop
Tree saplings establish
from the surrounding Oak
forest on higher and
steeper slopes (transport
of matter from
surrounding ecosystems),
reducing amount of
grazing available
Continued grazing by
goats and cattle maintains
the Garigue as a semi-
climax community
Clearance of current
vegetation to provide
grazing and fuel
Secondary succession
leads to re-establishment
of mixed evergreen and
deciduous oak forest
climax community

106. Climax mixed evergreen
and deciduous oak forest
cover clearance to provide
grazing and fuel
Grazing by goats and
cattle maintains an open
Garigue community of low
spiny shrubs and aromatic
flowering plants with
grass patches between
Reduction in grazing
pressure (herbivory)
because of rural
depopulation and
changing farming
practices, in particular
fewer goat herds allows
more shrubs and tree
saplings to develop
Tree saplings establish
from the surrounding Oak
forest on higher and
steeper slopes (transport
of matter from
surrounding ecosystems),
reducing amount of
grazing available
Continued grazing by
goats and cattle maintains
the Garigue as a semi-
climax community
Clearance of current
vegetation to provide
grazing and fuel
Secondary succession
leads to re-establishment
of mixed evergreen and
deciduous oak forest
climax community

107. Climax mixed evergreen
and deciduous oak forest
cover clearance to provide
grazing and fuel
Grazing by goats and
cattle maintains an open
Garigue community of low
spiny shrubs and aromatic
flowering plants with
grass patches between
Reduction in grazing
pressure (herbivory)
because of rural
depopulation and
changing farming
practices, in particular
fewer goat herds allows
more shrubs and tree
saplings to develop
Tree saplings establish
from the surrounding Oak
forest on higher and
steeper slopes (transport
of matter from
surrounding ecosystems),
reducing amount of
grazing available
Continued grazing by
goats and cattle maintains
the Garigue as a semi-
climax community
Clearance of current
vegetation to provide
grazing and fuel
Secondary succession
leads to re-establishment
of mixed evergreen and
deciduous oak forest
climax community

108. Climax mixed evergreen
and deciduous oak forest
cover clearance to provide
grazing and fuel
Grazing by goats and
cattle maintains an open
Garigue community of low
spiny shrubs and aromatic
flowering plants with
grass patches between
Reduction in grazing
pressure (herbivory)
because of rural
depopulation and
changing farming
practices, in particular
fewer goat herds allows
more shrubs and tree
saplings to develop
Tree saplings establish
from the surrounding Oak
forest on higher and
steeper slopes (transport
of matter from
surrounding ecosystems),
reducing amount of
grazing available
Continued grazing by
goats and cattle maintains
the Garigue as a semi-
climax community
Clearance of current
vegetation to provide
grazing and fuel
Secondary succession
leads to re-establishment
of mixed evergreen and
deciduous oak forest
climax community
Alternative
stable
state

109. Secondary Succession
Climax mixed evergreen
and deciduous oak forest
cover clearance to provide
grazing and fuel
Grazing by goats and
cattle maintains an open
Garigue community of low
spiny shrubs and aromatic
flowering plants with
grass patches between
Reduction in grazing
pressure (herbivory)
because of rural
depopulation and
changing farming
practices, in particular
fewer goat herds allows
more shrubs and tree
saplings to develop
Tree saplings establish
from the surrounding Oak
forest on higher and
steeper slopes (transport
of matter from
surrounding ecosystems),
reducing amount of
grazing available
Continued grazing by
goats and cattle maintains
the Garigue as a semi-
climax community
Clearance of current
vegetation to provide
grazing and fuel
Secondary succession
leads to re-establishment
of mixed evergreen and
deciduous oak forest
climax community
Alternative
stable
state

110. Secondary Succession
Climax mixed evergreen
and deciduous oak forest
cover clearance to provide
grazing and fuel
Grazing by goats and
cattle maintains an open
Garigue community of low
spiny shrubs and aromatic
flowering plants with
grass patches between
Reduction in grazing
pressure (herbivory)
because of rural
depopulation and
changing farming
practices, in particular
fewer goat herds allows
more shrubs and tree
saplings to develop
Tree saplings establish
from the surrounding Oak
forest on higher and
steeper slopes (transport
of matter from
surrounding ecosystems),
reducing amount of
grazing available
Continued grazing by
goats and cattle maintains
the Garigue as a semi-
climax community
Clearance of current
vegetation to provide
grazing and fuel
Secondary succession
leads to re-establishment
of mixed evergreen and
deciduous oak forest
climax community
Alternative
stable
state
Cyclic change

111. Secondary Succession
Climax mixed evergreen
and deciduous oak forest
cover clearance to provide
grazing and fuel
Grazing by goats and
cattle maintains an open
Garigue community of low
spiny shrubs and aromatic
flowering plants with
grass patches between
Reduction in grazing
pressure (herbivory)
because of rural
depopulation and
changing farming
practices, in particular
fewer goat herds allows
more shrubs and tree
saplings to develop
Tree saplings establish
from the surrounding Oak
forest on higher and
steeper slopes (transport
of matter from
surrounding ecosystems),
reducing amount of
grazing available
Continued grazing by
goats and cattle maintains
the Garigue as a semi-
climax community
Clearance of current
vegetation to provide
grazing and fuel
Secondary succession
leads to re-establishment
of mixed evergreen and
deciduous oak forest
climax community
Alternative
stable
state
Cyclic change

112. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Why would rural depopulation in lead to secondary
succession?
Between the 1960s and the early 2000s the
number of farms in France fell from over
3,000,000 to less than a 1,000,000 A major
problem for
biodiversity

113. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Valley of the River L’Agly in the 1900 and 2023

114. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

115. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Garage communities
depend on cycles of
disturbance
Man clearing the land
Goats grazing the land

116. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession

117. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
As Primary succession
progress net productivity
usually increases to a
maximum then decreases
as the community reaches
a climax state

118. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Why might
this be the
case?

119. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
As Primary succession
progresses net
productivity usually
increases to a maximum
then decreases as the
community reaches a
climax state
Why might
this be the
case?

120. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
Why might
this be the
case?

121. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
As Primary succession
progresses net
productivity usually
increases to a maximum
then decreases as the
community reaches a
climax state
Why might
this be the
case?

122. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
As Primary succession
progresses net
productivity usually
increases to a maximum
then decreases as the
community reaches a
climax state

123. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
As Primary succession
progresses net
productivity usually
increases to a maximum
then decreases as the
community reaches a
climax state
Successional stage of the garage with rapidly growing young tree
saplings
Mature closed forest with trees only growing slowly
1
2

124. Topic 2: Ecosystems and
Ecology
Topic 2.4: Biomes, Zonation and Succession
As Primary succession
progresses net
productivity usually
increases to a maximum
then decreases as the
community reaches a
climax state
Successional stage of the garage with rapidly growing young tree
saplings
Mature closed forest with trees only growing slowly
1
2
1
2

125. Work cited:
“Mediterranean Vegetation.” A Guide to the Vegetation of Britain and Europe,
by Oleg Polunin and Martin Walters, Oxford University Press, 1985, p. 131.
Lichfield, John. “How Rural France Died.” The Independent, 1 Sept. 1999.
NB* Unless stated in the presentation all illustrations, figures and images are the property and copyright of N Gardner. sciencebitz.com
Topic 2: Ecosystems and
Ecology
Topic 2.2: Communities and Ecosystems