ReFFECT: Restoration of Headwater Streams: Combining ... · Turunen et al. Differential responses by stream and riparian biodiversity to restoration of forestry-impacted streams

ReFFECT:

Restoration of Headwater Streams: Combining

Ecological, Hydrological and Socioeconomical

Perspectives

Jukka Aroviita

Finnish Environment Institute (SYKE), Freshwater Centre

The ReFFECT Consortium:

University of Oulu, Stream Ecology: Timo Muotka, Pauliina Louhi, et al

University of Oulu, Hydrology: Björn Klöve, Hannu Marttila, et al.

SYKE: Jukka Aroviita, Jarno Turunen, Virpi Lehtoranta, Sari Väisänen et al.

+ State Forest Enterprise (Metsähallitus): Pirkko-Liisa Luhta et al.

Sustainable Governance of Aquatic Resources Research Programme (AKVA) - Final Symposium, 9 Dec 2016, Helsinki

Lakes Streams

Uomaverkosto: SYKE, ELY-keskukset

© Vesa Kuusava, Ympäristöhallinnon kuvapankki; Maria

Rajakallio Syke; Oskari Härmä / e-Oppi Oy (peda.net)

http://www.ymparisto.fi/fi-FI/Kartat_ja_tilastot/Vesistojen_ravinnekuormitus_ja_luonnon_huuhtouma

59% of phosphorus comes from agriculture

AGRICULTURE

FORESTRY

POINT

SOURCES

Roads

Drainage networks

Harvest

Harvest

Stream

50 km

55 % of peatlands in Finland have been drained to enhance forest growth

Drained peatlands

Lakes

Undrained peatlands

or mineral lands Soiden ojitustilanne: SYKE (pohjautuu MML aineistoon), Uomaverkosto:

SYKE, ELY-keskukset; Oskari Härmä / e-Oppi Oy (peda.net)

Sedimentation causes

biodiversity loss in streams

Turunen et al. Differential responses by stream and

riparian biodiversity to restoration of forestry-impacted

streams. Submitted.

Sedimentation may also modify

functions and trophic cascades in

streams

Louhi et al. 2016. Sediment addition reduces the

importance of predation on ecosystem functions in

experimental stream channels. Canadian Journal of

Fisheries and Aquatic Sciences 73: 1–9.

ReFFECT:

How to improve the status of

streams effectively?

2. Disentan-

gle stressor effects.

3.

Effects of different

restoration methods.

4. Quantify stressor

and habitat effects.

1.

Explore public values.

=> Correlative

analyses using

large-scale

monitoring

data.

=> Questionnaires

on appreciation

and WTP.

=> Field surveys in

restored, stressed

and natural streams.

=> Mesocosm

experiments

in artificial

channels.

A survey in 2014

● 1,782 inhabitants

● 39 % response rate

3 groups:

● Residents 33%

● Forest owners 50%

● Forest entrepreneurs 17%

Appreciation of ecosystem

services and restoration of forest

streams

1.

Public values and willingness

to pay.

Lehtoranta et al. Public values for stream restoration in forested watersheds: Does land ownership or preference

uncertainty matter? Submitted.

Residents and forest owners agreed more that:

● Restoration is needed

● Current condition is not good

68% of the respondents were willing to pay

something, on average 10–22 € annually

Forest entrepreneurs agreed more that:

● Damage exaggerated

● Current condition OK

Differences in thoughts and valuing 1.


to pay.



WTP explained by interest to flood mitigation,

trout conservation and water quality issues.

But not by biological diversity.

Difference in appreciation: “Appreciates very

much”:

○ Clean water: 70 %

○ Biological diversity: 25 %

=> Forest owners & entrepreneurs should be

more involved, and at early stages

=> Need to “sell” restoration programmes in

laymans terms

WTP and appreciation 1.


to pay.



Conclusions

Stream restoration has traditionally

focused on channel morphology

But: ecological responses often weak, if

any

=> What are the independent effects of

diffuse pollution and morphological

channel alteration on stream biota?

How to prioritize management actions? 2. Disentan-

gling stressor effects.

Reference, no stressors HyMo altered, no diffuse pollution

Diffuse pollution,

no HyMo alteration

Both stressors present

2. Disentan-


http://www.syke.fi/hankkeet/maamet

Even at low stressor levels: Agricultural

diffuse pollution much worse than

HyMo-changes

2. Disentan-


Turunen et al. 2016. Disentangling the responses of boreal stream assemblages to low stressor levels of diffuse

pollution and altered channel morphology. Science of the Total Environment 544: 954–962.

Macrophytes

Reference Hydromorphological alteration Diffuse nutrient pollution Both stressors

Diatoms Benthic fauna

NMS 1

NM

S 2

N=91 streams

18-24 per ”treatment”

=> Mitigation of diffuse pollution of

nutrients and organic matter from

catchments should be a priority.

Conclusion for management:

Turunen et al. 2016. Disentangling the responses of boreal stream assemblages to low stressor levels of diffuse

pollution and altered channel morphology. Science of the Total Environment 544: 954–962.

2. Disentan-


Turunen et al. Differential responses by stream and riparian biodiversity to restoration of forestry-impacted streams. Submitted.

Boulder restoration

Headwater stream restoration, two

approaches:

3.



Wood restoration

33 streams in River Iijoki catcment:

- Near-natural reference streams

- Sediment-stressed from drainage (IMP)

- Stressed, restored mainly with boulders

- Stressed, restored mainly with wood

3-7 yrs after restoration

3.



Boulder restoration increased

aquatic bryophyte richness

while wood restoration did not.

Wood restoration altered riparian

vegetation towards near-natural

communities.


Unpublished figure not

shown


shown

3.




Marttila et al. Restoration with wooden debris increase transient storage in boreal headwater streams. manuscript.

Boulder restoration decreased

fine sediment cover while

wood restoration did not.

Wood restoration increased hydraulic

retention to near-natural level.


shown


shown

3.



Benthic fauna showed signs of

recovery in boulder restored streams.



shown

4. Quantifying

stressor and habitat

effects.

Mosses decrease the harmful

sediment effects.

Turunen et al. Sedimentation, habitat loss and connectivity as drivers of biodiversity change in boreal streams? In preparation.


shown

● Biotic responses: taxon-specific and slow to

emerge

● Boulder restoration => Mosses

● Wood restoration => Hydrology => riparian zone

● Streams are tightly linked to the riparian zone.

Flooding is natural.

● In long term: Self-sustaining loop back to

stream?

Conclusions

3.



4. Quantifying

stressor and habitat

effects.

ReFFECT:

How to improve status of streams

effectively?

2. Mitigate loading from catchment.

3.

Use stones AND natural

wood.

4. Mosses and natural

riparian zone key to recovery.

1. Involve forestry,

”sell” restoration.

Public

values

Field surveys

Experi-

ments

Large-

scale data

Documents

ReFFECT: Restoration of Headwater Streams: Combining ... · Turunen et al. Differential responses by stream and riparian biodiversity to restoration of forestry-impacted streams