1st-Urban River as Dispersal Corridors-b

8/8/2019 1st-Urban River as Dispersal Corridors-b

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OUTLINE

1.Introduction2.Material and Methode

3.Results

4.Conclusion

Urban River as Dispersal Corridors | Arief Nugroho Nur Prasetyo | R100064

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Introduction


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UrbanizationGlobal

WarmingBiodeversity

Severely

Role of dispersal corridors


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IntroductionThe possible function of urban rivers as dispersal -

corridors has not been considered in planning,

design, and management approaches for urban

river greenways (e.g., Baschak and Brown, 1995).

They analyze the seed dispersal of three tree

species:

the EuropeanAcer platanoides L.,

the North AmericanAcer negundo L.,

the AsianAilanthus altissima Mill. Swingle.


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Material and MethodeThey use a direct experimental approach visual tracking of

oating seeds had been marked with different colours

They collected fruits randomly chosen trees in Berlin during

the period of natural seed abscission

Measured dry weight [DW], maximum wing length [L ], andmaximum wing width [W] (meansSD for N=50) with the following

results :

Ailanthus altissima (DW=528mg, L =463mm, W =111mm)

Acer negundo (DW=4810mg, L =322mm, W =101mm)

Acer platanoides (DW=17726mg, L =534mm, W =192mm).

Then they tagged samaras with different colours of spray paint

(Aero Decor Colour-Spray, Union Chemie Berlin, Germany).


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Material and Methode (Advanced)

For the eld experiment, they chose the Spree River in the centre

of Berlin with a length of 1200m and a width of 40 80m.

The experiments were carried out on calm (wind velocity


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Material and Methode

An ANOVA was used to determine:

o the species-specic effects

o the effects of turbulence (caused by boats) in the rst

observation sectiono the effects of oating distance on oating capacity (i.e.,

average number of oating fruits per cohort) and the

interactions species distance and species boat

turbulence.


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Results


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The experiment revealed that

the number of released fruits

that arrived at the observation

points declined exponentially.

There is interspecies

differences in the number of

arriving samaras after a water

transport over 200m, but no

interspecic differences overtransport distances of 20 and

1200m more [Tab. 1&2]


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Results


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Water turbulence decreased the number of oating

samaras in bothAcerspecies, but not inAilanthus.

After 1200m of oating, the interspecic differences

disappeared.


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Results


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There were no speciesturbulence or speciesdistance

interactions.


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Conclusions


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Three main conclusions for urban design and conservation

can be derived from the results:

When designing tree plantings along urban river

embankments or at other sites within the spatial reach of

rivers, the potential of water dispersal for wind-dispersed

species should be considered.

Tree species with a high invasion potential should be

replaced by native tree species.

When individuals of invasive trees with samara-like fruits

rst emerge in natural riparian systems, early eradication

should be considered to prevent a further spread byhydrochory.


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Thank You..


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1st-Urban River as Dispersal Corridors-b