ecosystem functions and ecosystem services ecosystem ......esf and ess of riparian ecosystems...

University of Trier, TU Berlin Thomas, Kleinschmit

ESF and ESS of riparian ecosystems SuMaRiO Final Conference, Munich, 10.-11.12.2015

Geobotany, University of Trier

Ecosystem Functions and Ecosystem Services –

Ecosystem Services of Riparian Ecosystems

Frank M. THOMAS, Birgit KLEINSCHMIT


Key ecosystem processes:

• Primary productivity;

• Resource consumption;

• Trophic interactions;

• Respiration;

• Decomposition.


Ecosystem Functions and Ecosystem Services –

Definitions

Reiss et al. (2009), Trends in Ecology and Evolution 24: 505-514:

Ecosystem functions (ESF) = ecosystem processes:

"Changes in energy and matter over time and space through biological activity …

governed by the interplay of abiotic factors, [mediated] by organisms."

"Ecosystem functioning: the joint effects of all processes that sustain an ecosystem."

Pale arrows: energy flow

Dark arrows: nutrients in organic matter

DOM: dead organic matter

NPP: net primary production

(from: Begon et al. 2006, Ecology. Blackwell)

Nutrients in inorganic form

ESF studied in riparian forests:

• Production of above-ground tree biomass;

• Water use.

Ecosystem services (ESS) comprise:

• Provisioning services (PS): e.g., production/storage of food, water, fiber, fuel;

• Supporting services (SS): e.g., biomass production, nutrient cycling, soil formation;

• Regulating services (RS): e.g., mitigation of disturbances and catastrophic events;

• Cultural services (CS): e.g., recreation, education, spiritual benefits.


Ecosystem Services – Definition

Millenium Ecosystem Assessment (Hassan et al. 2005, vol. 1):

"Ecosystem services are benefits people obtain from ecosystems."

ESS studied in riparian forests:

• PS, SS: Production of above-ground tree biomass;

• RS: Shelter from sand drift.


Establishment of seedlings (generative phase);

Shoots partly covered with sand (or decrease in the

groundwater level) (onset of vegetative phase);

Dune formation. (M. Manegold)

Rapid root

growth of

P. euphratica

Populus euphratica is a phreatophyte …

... "a plant that habitually obtains its water supply from the zone

of saturation, either directly or through the capillary fringe."

(Meinzer 1923, U.S. Geological Survey Water-Supply Paper 494).

(from: Runge M. 2004; in: Runge M, Zhang X (eds.), Shaker, Aachen)



In Populus euphratica,

root suckers can form

extensive clones


0

20

40

60

80

100

020406080100

0

20

40

60

80

100

0 20 40 60 80 100

-360

-330

-300

-270

-240

-210

-180

-150

-120

-90

-60

-30

P69P70P73P72P71P68P67

P51P54P56P55P53P52P57P58P76P78P79P80P83P84

P94P93P64P65P66P47P48

P74P75

S42S43

S44S45

S46S47S48

S49

S50

S51S52

S53S54

S55

S56

S57

S58

S59

S60

S61S62S63S64S65S66 S67S68 S69 S70 S71 S72 S73 S74

S75S76

S77

S78

S79

S80

S81

S82

S83S84

S85

S86

S87S88

S89

S90

S91

S92

S93

S94

S95

S96

S97S98S99

S100

S101S102

S103

S104

S105

S106S107S108S109S110S111S112S113

S114S115

S116S117S118

S119

N

E

S

W

= sampled trees

Radius 100 m

(Bruelheide et al. 2004)Clone size of Populus euphratica:

up to 121 ha (Vonlanthen et al. 2010, Am J Bot)

→ Vegetative regeneration gains importance (but is increasingly hampered)

with increasing distance to the groundwater.


Populus euphratica stands growing at

larger distances to the groundwater …


… are older and sparser,

… have a lower capability of regeneration;

→ will eventually die off.


0

20

40

60

80

0

100

200

300

400

500

0 2 4 6 8 10 12

Me

an t

ree

ag

e (

ye

ars

)

Stand

den

sity (t

rees

ha-1 )

Groundwater distance (m)

Trends in post-disturbance recovery rates of Tugai forest following drought

• MODIS time series NDVI, 250m, 16-days

• Populus – 330 m from Tarim (Arghan)

• positive trends with break in July 2007

• break after 8th water diversion (1 yr lag)


• Tamarix – 1km from Tarim (near Korghan)

• strong positive trend after first water

diversion

• followed by a trend break in Sept 2002

• steady state since then

NDVI as aboveground biomass indicator


Trends in post-disturbance recovery rates of Tugai forest following drought


• Herbaceous (reed) – 900 m from Tarim (near

Korghan)

• after flooding (12th water diversion) strong positive trend

• land cover change from desert (barren) to steppe

• triggered due to river regulation?

12th

River regulation

2014

2010

2004

NDVI as aboveground biomass indicator


ESF and ESS of riparian ecosystems

C

B

A

• Two time periods under investigation

(1984-1999 & 2000-’15) with Landsat Sensor

• More than 1/2 of poplar & grass area has negative trend

before water diversion (middle section)

• Upper & Middle section have highest trend increase

after water diversion

Trends in post-disturbance recovery rates of Tugai forest

A B C

Riparian Populus euphratica forests: study sites

Hyper-arid climate:

Annual precipitation:

33 – 104 mm;

Annual mean temperature:

11 °C;

Annual potential evaporation:

ca. 2600 mm.

Projects: Xayar: SuMaRiO (2011 – 2015)

Cele: EU INCO-DC, 1998 – 2001


Village of Gezkum

(near Xayar)

Cele (Qira)

Oasis


Structure of the Populus euphratica stands

Site and plot Y1 X1 A1

(+ tEW1)

A2 A3 Y2 Y3

Distance to groundwater (m) 2.0 2.0 5.0 5.0 6.6 7.5 12.0

Tree age (years; 3-year average) 26 30 46 37 52 28 77

Stand density (trees ha -1) 467 121 166 257 59 378 67

Tree cover (%) 81 20 31 29 5 35 6

Basal area (m2 ha-1) 18.7 5.9 15.9 16.4 5.8 15.7 13.3

Total above-ground tree biomass (t ha-1) 55.6 13.9 28.0 25.6 6.9 31.3 15.6

X = Xayar; Y = Yingbazar, A = Arghan; 1 → 3: decrease in water supply

(Data from Diploma Theses of J. Ahlborn and P. Schäfer)

→ Larger groundwater distance older, sparser stands; lower biomass.

1 temporary "ecological water"



Above-ground wood production of poplar stands

in the last 3 years of analyses

→ Significant relationships with tree age and stand density via groundwater distance.


• Productivity within the range of typical woody desert vegetation (≤ 2.6 t ha-1 a-1),

• but lower than in young (20-yr-old) coppice stands (≤ 6.1 t ha-1 a-1; Qira site);

Groundwater distance (m)

0 2 4 6 8 10 12

Pro

ductivity (

t ha

-1 a

-1)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

X1

Y1

Y2

Y3

A1A2

A3

R² = 0.227

P = 0.280

Stand density (trees ha-1

)

0 100 200 300 400 500

X1

Y1

Y2

Y3

A1 A2

A3

Tree age (years)

0 20 40 60 80

Pro

ductivity (

t ha

-1 a

-1)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

X1

Y1

Y2

Y3

A1A2

A3

R² = 0.591

P = 0.0435 *

R² = 0.9422

P < 0.001 ***


Wood production calculated using tree-ring analyses and allometric regressions adopted from Chen & Li (1984),

For. Sci. Technol. Xinjiang 3: 8-16

Yingbazar Arghan

→ Trees at small groundwater distance potentially larger basal area increment.

Tarim River

water overuse?

Groundwater distances: long-term BAI increment

Small distance to GW (Y1, A1)

Intermediate distance to GW (Y2, A2)

Large distance to GW (Y3, A3)

Ecological

water?



Changes in the course of the Tarim River

→ unchanged river course only since 1973.

Middle reaches

(from: Thevs et al. 2008, Phytocoenologia 38: 65-84)



Study site Yingbazar:

basal area increment related to river run-off

Populus euphratica stand at a close distance to the groundwater (Y1; 2.0 m);

1971 – 2005; river run-off of the preceding years:

Stands with close distance

to the groundwater suffer

significantly from a

decrease in water supply;

! No such relationships in

plots with larger distances

to the groundwater.

(Data from Diploma Thesis J. Ahlborn and from Thevs et al. 2008, Phytocoenologia 38: 65–84)


Preceding year's river run-off (106 m

3)

0 1000 2000 3000 4000 5000

Ba

sa

l a

rea

in

cre

me

nt

(cm

2 a

-1)

0

5

10

15

20

25

r = 0.5337

P = 0.0014


Study site Xayar:

Effects of use intensity (wood harvest by pollarding)

No pollarding

(tree height: 11.9 m)

Moderate pollarding


Intense pollarding


(T. Backes) (T. Backes) (T. Backes)



Year

1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

Mea

n a

nn

ua

l B

AI

(cm

2 a

-1)

0

5

10

15

20

25

Num

be

r o

f b

ranch

es (

> 1

0 c

m)

0

5

10

15

20

25

30

35No use Moderate useIntense use

a

a

a

Last pollarding event: 1987

Estimated recovery period: 3 years


Study site Xayar:

Use intensity and basal area increment

a

ab

b → Pollarding: smaller BAI

(intense use, 1987-2010).

(From: Lang et al. 2015, For. Ecol. Manage. 353: 87–96)


Plant species Coverage (%)

Y1 Y2 Y3 A1 A2 A3

Populus euphratica, T 18 15 3 11 13 2

Populus euphratica, S 1 2 0.3 0.3

Tamarix ramosissima, S 1 0.2 4 < 0.1

Halimodendron halodendron, S 0.5

Lycium ruthenicum, S 0.2 < 0.1

Cynanchum sibiricum, S 0.1

Populus euphratica, H 0.1 < 0.1

Tamarix ramosissima, H < 0.1

Phragmites australis, H 25

Glycyrrhiza inflata, H 0.8

Cirsium cv. arvense, H < 0.1

Heteropappus altaicus (?), H < 0.1

Mean number of species 6.7 2 1 1.6 1.2 0.8

A word on biodiversity …

→ Riparian forests are species-poor, but can harbor important medicinal plants.


3 – 5 relevés per plot, 400 m2; T = tree layer, S = shrub layer, H = herb layer


Conclusions

With increasing distance to the groundwater level …:

• … Poplar trees are older and lose their capability of generative (and vegetative)

regeneration;

• … Poplar stands are sparser, genetically less diverse, display a reduced tree cover

and produce less wood;

• … Tree growth becomes decoupled from water supply by the river;

→ Redirection of water from stands close to the groundwater towards stands

with larger distances to the groundwater might reduce growth in stands close

to groundwater.


• Poplar trees can tolerate moderate intensities of wood harvesting by pollarding

→ moderate pollarding should be permitted to make use of this renewable resource.


Supplementary water from river run-off fosters recovery of vegetation

and enhances stem increment growth (up to a distance of 5 m above GW level?).

Thank you for your attention!

Acknowledgements:

BMBF, Sustainable Land

Management, SuMaRiO, 01LL0918K




Genetic diversity within poplar stands: Arghan siteStand A1

GW distance: ≈ 5 m

(+ "ecological water")

Mean tree age: 41 yr

Stand A2

GW distance: ≈ 5 m


Stand A3

GW distance: 6.6 m


AFLP fingerprinting and

Neighbor-Joining

by T. Schmitt & K. Kramp,

Senckenberg Institut,

Müncheberg

→ Stand A1:

rel. low genetic similarity;

Stand A3:

rel. high genetic similarity;

but:

almost no clones at this site!

Recovery from pollarding

→ Even intensely pollarded poplars are able to recover from pollarding.

Index of resilience IR:

ratio of the three-year averages of the annual BAI after and before the pollarding event;

IR ≥ 1: full recovery or increase in growth; IR < 1: decline in growth after pollarding

Pollarding intensity IR (means ± 1 standard deviation) Significantly different from 0?

Moderate 0.79 ± 0.36 a No

High 0.91 ± 0.40 a No



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