WEBVTT - generated by Videoportal Freiberg

1
00:00:01.379 --> 00:00:03.910
Now we will continue with threatens to the
ecosystems due to human activities.

2
00:00:04.010 --> 00:00:06.550
We have discussed already a number of them.

3
00:00:07.079 --> 00:00:13.609
And at least still, even if this paper is from
2001,

4
00:00:13.710 --> 00:00:16.399
they are still valid.

5
00:00:18.399 --> 00:00:22.829
The most important driver

6
00:00:22.930 --> 00:00:27.040
for changing biodiversity, which was our topic
now,

7
00:00:28.059 --> 00:00:31.469
00:00:32.080 --> 00:00:36.529 is land use and
land use change.

8
00:00:37.209 --> 00:00:39.610
So, at least in those parts like here, for
example,

9
00:00:39.709 --> 00:00:42.549
in eastern Germany or western Germany, west
of Cologne,

10
00:00:43.889 --> 00:00:47.000
the landscape has been dramatically changed.

11
00:00:48.279 --> 00:00:50.279
And, of course

12
00:00:51.689 --> 00:00:56.120
in the back of it, usually there is a negative
effect on biodiversity,

13
00:00:56.220 --> 00:00:58.000
there will be less species.

14
00:00:58.099 --> 00:01:02.000
And on the other hand, there will be new species,

15
00:01:03.000 --> 00:01:08.000
which we'll discuss later on, which are due
to biotic exchange.

16
00:01:10.000 --> 00:01:14.000
The effect of climate will increase, for sure,

17
00:01:14.000 --> 00:01:18.000
in the next time.

18
00:01:20.000 --> 00:01:22.000
As another cause changing biodiversity,

19
00:01:23.000 --> 00:01:28.000
I will discuss N-deposition now shortly.

20
00:01:29.000 --> 00:01:32.000
As I said, it is also very important in our
post-mining landscape

21
00:01:32.000 --> 00:01:36.000
as an external input of nutrients

22
00:01:37.000 --> 00:01:43.000
apart from natural nitrogen fixation and apart
from human fertilization.

23
00:01:44.000 --> 00:01:49.000
The atmospheric CO2 will also change biodiversity.

24
00:01:49.000 --> 00:01:53.000
I will not discuss this much detail because
it requires

25
00:01:54.000 --> 00:01:56.000
a deeper knowledge of plant physiology.

26
00:02:00.000 --> 00:02:02.000
So, I will skip this.

27
00:02:02.000 --> 00:02:08.000
Deposition

28
00:02:08.000 --> 00:02:10.000
or in general, pollution,

29
00:02:13.000 --> 00:02:16.000
that's a very complicated, graph.

30
00:02:18.000 --> 00:02:22.000
It shows you that there is a huge amount

31
00:02:25.000 --> 00:02:29.000
of sources for pollution and different categories.

32
00:02:29.000 --> 00:02:33.000
So we have pollution of air and we have pollution
of water

33
00:02:33.000 --> 00:02:39.000
and land. Pollution of air can be either in
the form of gases,

34
00:02:40.000 --> 00:02:46.000
which, for example, cause a smog, or

35
00:02:46.000 --> 00:02:52.000
cause some acids being formed, which you see
in more detail

36
00:02:52.000 --> 00:02:54.000
later on, or particulate matter.

37
00:02:56.000 --> 00:02:58.000
This dates also not only from human activities

38
00:02:58.000 --> 00:03:04.000
such as fossil fuel burning, as you can see
here

39
00:03:04.000 --> 00:03:09.000
in chemical factories or motorcars.

40
00:03:10.000 --> 00:03:14.000
Particulate matter can be also, for example,
due to wind erosion in post mining landscapes.

41
00:03:17.000 --> 00:03:23.000
Then we have these chemicals, which luckily
now are less important

42
00:03:24.000 --> 00:03:27.000
because there was the important Montreal Protocol

43
00:03:27.000 --> 00:03:32.000
which initiated a ban on producing these chlorinated

44
00:03:33.000 --> 00:03:35.000
and fluorinated carbons.

45
00:03:35.000 --> 00:03:40.000
We will discuss a little bit later their former
use in air conditioners

46
00:03:40.000 --> 00:03:42.000
or refrigerators and others.

47
00:03:43.000 --> 00:03:48.000
Then we have all these either liquid or solid
waste,

48
00:03:48.000 --> 00:03:52.000
for example, nuclear waste, which will be

49
00:03:54.000 --> 00:04:01.000
a long-term problem, especially now since due
to CO2 greenhouse effect,

50
00:04:01.000 --> 00:04:05.000
and due to the energy crisis or energy price
crisis,

51
00:04:06.000 --> 00:04:11.000
as a consequence of the Russian aggression
in Ukraine

52
00:04:11.000 --> 00:04:17.000
there are more countries relying now on

53
00:04:20.000 --> 00:04:24.000
nuclear power.

54
00:04:24.000 --> 00:04:27.000
Then, we have and this will be also maybe more
important

55
00:04:28.000 --> 00:04:33.000
in the future with the food crisis also partly
due to the war in the Ukraine

56
00:04:34.000 --> 00:04:38.000
and a more intensive use of pesticides and
herbicides.

57
00:04:39.000 --> 00:04:45.000
Maybe just one comment on all these discussions

58
00:04:45.000 --> 00:04:47.000
going on also in Germany

59
00:04:48.000 --> 00:04:55.000
that we may have less food

60
00:04:55.000 --> 00:04:57.000
available for us and that we have to increase

61
00:04:57.000 --> 00:05:03.000
food production per area of land, which means

62
00:05:03.000 --> 00:05:08.000
we have to invest more fertilizers, that we
have to invest

63
00:05:08.000 --> 00:05:13.000
more in pesticides, maybe also in genetically
modified

64
00:05:13.000 --> 00:05:17.000
organisms, and that we should rely less on
organic farming.

65
00:05:19.000 --> 00:05:21.000
Just one comment.

66
00:05:21.000 --> 00:05:23.000
Every day

67
00:05:23.000 --> 00:05:29.000
we are still transforming huge areas of land

68
00:05:30.000 --> 00:05:36.000
into built-up areas like houses,

69
00:05:37.000 --> 00:05:42.000
like industrial facilities, like traffic infrastructure
and so on.

70
00:05:43.000 --> 00:05:48.000
So, we are steadily losing very valuable arable
land to

71
00:05:50.000 --> 00:05:56.000
built-up lands, causing soil compaction  and
loss of biodiversity.

72
00:05:57.000 --> 00:06:02.000
which is reducing our capacity to grow food.

73
00:06:04.000 --> 00:06:07.000
We already have discussed in the last presentations

74
00:06:07.000 --> 00:06:11.000
that we have toxic chemicals, for example,
from mining,

75
00:06:11.000 --> 00:06:16.000
oil spills and others from transporting

76
00:06:19.000 --> 00:06:24.000
fuels. And of course, from industrial

77
00:06:26.000 --> 00:06:28.000
factories and so on.

78
00:06:29.000 --> 00:06:30.000
Solid waste.

79
00:06:30.000 --> 00:06:32.000
And then we have

80
00:06:33.000 --> 00:06:37.000
nutrient oversupply, which I will discuss also
a little bit,

81
00:06:38.000 --> 00:06:44.000
nutrient oversupply on land and due to erosion

82
00:06:45.000 --> 00:06:46.000
when these nutrients

83
00:06:46.000 --> 00:06:51.000
will be washed out from soils and leached into
groundwater,

84
00:06:51.000 --> 00:06:56.000
into surface waters and finally into the oceans.

85
00:06:57.000 --> 00:07:01.000
For example, the Baltic Sea is heavily affected
by high loads of nitrogen.

86
00:07:04.000 --> 00:07:11.000
Another consequence of erosion

87
00:07:11.000 --> 00:07:17.000
is sediments, sediments from arable land or
from mining sites

88
00:07:17.000 --> 00:07:22.000
and others, which will, for example,

89
00:07:23.000 --> 00:07:25.000
again land up in water bodies.

90
00:07:26.000 --> 00:07:31.000
00:07:31.760 --> 00:07:36.109

91
00:07:36.000 --> 00:07:38.000
00:07:40.649 --> 00:07:47.489

92
00:07:48.000 --> 00:07:53.000
00:07:55.010 --> 00:08:00.109 This is a short
overview on

93
00:08:01.000 --> 00:08:04.000
possible sources

94
00:08:05.000 --> 00:08:09.000
and pathways of pollution.

95
00:08:13.000 --> 00:08:16.000
Let's start with the N-deposition,

96
00:08:18.000 --> 00:08:22.000
which can serve as a

97
00:08:24.000 --> 00:08:28.000
fertilizer, and of course, you may argue: Fertilizer
�

98
00:08:28.000 --> 00:08:30.000
why is it bad?

99
00:08:31.000 --> 00:08:33.000
Well, as I said, for example, in post-mining
landscape,

100
00:08:33.000 --> 00:08:39.000
it could help to accelerate the process of
revegetation.

101
00:08:41.000 --> 00:08:46.000
Revegetation of forests, for example, where
foresters

102
00:08:46.000 --> 00:08:52.000
usually do not apply fertilizer, which may

103
00:08:52.000 --> 00:08:55.000
support tree growth.

104
00:08:55.000 --> 00:08:59.000
Thus, high N depositions are one of the reasons
why presently we see accelerated tree growth,

105
00:09:00.000 --> 00:09:02.000
particularly in the northern hemisphere.

106
00:09:04.000 --> 00:09:09.000
Two other important reasons are increased CO2
concentration

107
00:09:10.000 --> 00:09:15.000
and a longer growing season with higher temperatures.

108
00:09:15.000 --> 00:09:18.000
That is one thing.

109
00:09:19.000 --> 00:09:25.000
The bad thing is that we have nitrogen eutrophication

110
00:09:26.000 --> 00:09:32.000
all over our landscapes, all over our ecosystems,

111
00:09:32.000 --> 00:09:38.000
which means also those which are by nature
nutrient poor,

112
00:09:38.000 --> 00:09:39.000
for example

113
00:09:39.000 --> 00:09:44.000
peatlands called bogs. This means that

114
00:09:45.000 --> 00:09:49.000
there is an invasion of faster growing species
on bogs.

115
00:09:51.000 --> 00:09:53.000
This means the

116
00:09:53.000 --> 00:09:55.000
native vegetation, the native plant species,

117
00:09:55.000 --> 00:09:59.000
and also then, of course, the animals in bogs
are highly endangered.

118
00:10:01.000 --> 00:10:07.000
But the second aspect of nitrogen is that it's
also part

119
00:10:07.000 --> 00:10:11.000
of acid deposition, which comes

120
00:10:12.000 --> 00:10:14.000
on the one hand from sulfur dioxide,

121
00:10:15.000 --> 00:10:19.000
but also from nitrogen oxides, which are either
emitted

122
00:10:19.000 --> 00:10:22.000
by factories or by traffic.

123
00:10:24.000 --> 00:10:29.000
In the atmosphere nitrogen or sulfur oxides
combine with water vapor.

124
00:10:30.000 --> 00:10:35.000
And so, sulfuric acid, as you can see here,
or nitric acid,

125
00:10:35.000 --> 00:10:37.000
as you can see here, will be formed,

126
00:10:38.000 --> 00:10:43.000
which will return to our ecosystems in the
form of acid rain

127
00:10:45.000 --> 00:10:46.000
or acid snow,

128
00:10:46.000 --> 00:10:52.000
or also, if these sulfites, or nitrates are
combined

129
00:10:52.000 --> 00:10:58.000
with other particles in the air, then it will
be a dry fallout.

130
00:11:02.000 --> 00:11:06.000
So, it's not only the positive effect of nitrogen
as a fertilizer,

131
00:11:07.000 --> 00:11:12.000
it'll be negative effects of acid on vegetation,

132
00:11:12.000 --> 00:11:14.000
for example, damage of plants.

133
00:11:15.000 --> 00:11:18.000
Sulfates and nitrates also serve as nuclei
for condensation of water

134
00:11:19.000 --> 00:11:24.000
and create small droplets of very acidic character

135
00:11:24.000 --> 00:11:30.000
with pH 2 to 3, which will damage the leaves.

136
00:11:31.000 --> 00:11:36.000
And of course, in the very end, damage our
waterbodies,

137
00:11:37.000 --> 00:11:41.000
particularly in areas which are very poorly
buffered.

138
00:11:42.000 --> 00:11:45.000
And so, we have a strong decrease in pH,

139
00:11:47.000 --> 00:11:50.000
and a number of fish species may die out.

140
00:11:53.000 --> 00:11:58.000
The next slide shows us that acid rain

141
00:11:58.000 --> 00:12:02.000
was mainly caused by sulfur emissions.

142
00:12:03.000 --> 00:12:10.000
In the eighties it became evident

143
00:12:10.000 --> 00:12:16.000
that these sulfur emissions are the source
of acid rain.

144
00:12:16.000 --> 00:12:21.000
Thus, there were efforts in North America and
Western Europe

145
00:12:21.000 --> 00:12:23.000
to decrease the emission of sulfur oxides.

146
00:12:23.000 --> 00:12:30.000
And you can see there was a huge decrease in

147
00:12:31.000 --> 00:12:36.000
the amount of sulfur being emitted in Western
Europe

148
00:12:36.000 --> 00:12:41.000
down to only one third of the former level.

149
00:12:41.000 --> 00:12:47.000
Similarly  in North America, roughly one half.

150
00:12:47.000 --> 00:12:52.000
In Asia there is a steady increase due to increased
economic activities,

151
00:12:52.000 --> 00:12:54.000
particularly in Eastern Asia,

152
00:12:54.000 --> 00:12:59.000
whereas in Africa, S deposition is very low.

153
00:12:59.000 --> 00:13:03.000
In South America, it's increasing.

154
00:13:03.000 --> 00:13:05.000
And in Eastern Europe

155
00:13:06.000 --> 00:13:11.000
after the collapse of the Soviet

156
00:13:12.000 --> 00:13:18.000
economy, there was a decrease also by 50%.

157
00:13:20.000 --> 00:13:22.000
With this view of global trends of acid rain
I will close this session now.