Crop pollination in Norwegian Fjords and climate change

Report
Crop pollination in Norwegian
Fjords and climate change
Stein J. Hegland
1. Research Manager at the Norwegian Red deer Centre
2. Guest researcher at the University College of Sogn and Fjordane
My role
• Involved as national partner
– contribute to design and methodology etc
– administrate field work(ers) and collect data
– writing process
• Research interest: plant-animal interaction
– pollination ecology
– herbivory (mainly large herbivores)
• Authored conceptual review on plant-pollinator
mismatches in relation to climate warming:
Hegland, S.J., Nielsen, A., Lázaro, A., Bjerknes, A.L. & Totland, Ø.
(2009) How does climate warming affect plant-pollinator
interactions? Ecology Letters, 12, 184-195.
The Norwegian Fjords
• positive effects on
regional climate
• makes fruit
production possible
«close to arctic»
– ca 0-100 m.a.s.l
• climate gradients
are strong within
the fjords
An example from
ecological
research that
uses the climate
gradient:
SeedClim
http://www.uib.no/en/rg/EE
CRG/55395/seedclim
• Most important
Norwegian crops (in
tons):
1.
2.
3.
4.
5.
6.
7.
apple (11440)
strawberry (9122)
raspberry (2262)
plums (1102)
sweet cherry (537)
blackcurrant (592)
pears (360)
Crop pollination
• Pollinators are decisive or increase production
in 35% (#87) of world crops
• In 2005: value of insect pollination put to 153
million Euros annually (ca 10% of the total
value of the worlds agriculture)
• I Norway we know little, but we reckon that
most of the important crops need pollination
and in practise honey bees are often used as
additive to natural pollinators
Source: Christmann & Aw-Hassan (2012). Agriculture Ecosystems & Environment
Pollination of fruit and berries
Fruit
Pollinators
Bumblebees Solitary bees Honeybee
Syrphids
Other flies
Apple
x
x
x
x
Blackcurrant
x
x
x
Pears
x
x
x
Plums
x
x
x
x
Raspberry
x
x
x
x
Strawberry
x
x
x
x
Sweet cherry
x
x
x
x
Source: Klein et al. 2007. Proceedings of the Royal Society: Biological series
Importance
Large
Moderate
Moderate
Large
Large
Moderate
Large
• Norway: apple, rasberry and sweet cherries as likely
study candidates due to economics and dependence
on pollinators
Crop production and climate change
issues in Norway
• Today: Climatic sensibility to fruit production and pollination
– cold and wet weather in pollination season
• Climate change now and future: Increased and/or heavy
precipitation:
– less pollinators active + decrease in bees?
– harm flowers?
– increased parasite problems, especially fungi?
• tunnel production is partly an arrangement to meet these challenges
• Increased temperature: probably positive
– better pollination and growth
– more bee species in the long run?
– drought issues for some crops?
The Norwegian Fjords: a climate
change laboratorium?
• Gradients in temperature, precipitation and
sun exposure (local climate) within the fruit
growing area
• For
Fruit
growing
example
Part of gradient
the Sognefjord
July mean
fruit
Precipitation
districtExposure
area
temperature (°C)
(mm)
Lærdal
Inner
14-17
ca 500
flat (valley)
Luster
Inner
14-17?
ca 900
south-southeast
Leikanger
Middle
14-17
994
south
Vangsnes (Vik)
Outer
14-17
1138
north
Balestrand
Outer
14-17?
1700
southeast
Earlier flowering across time
Climate research challenges
• Previous table highlight the importance of assessing the
«real» climate gradient
– not necessarily linearly related to altitude or continentality!
– thus: establish the climate gradient may be important work
• How link changes in pollination success to climate changes?
– changes along climatic gradient is not enough!
– thus: observational gradients (within + among countries) +
experiments on important mechanisms?
•
•
•
•
•
bagging?
pollen supplementation?
warming treatment?
precipitation teatment?
etc!?
• An important task for this workshop?
A holistic view: crop pollination as part
of the landscape is the main strenght
of this project
How is the surrounding landscape
benefitting crop production?
• Many examples on how landscape configuration,
distance to and amount of (semi-)natural
elements etc
– affect pollinator diversity and abundance and
therefore crop pollination and production
• How about competition vs facilitation for pollinators
among native flowering resources and crops?
– Scale and distance matters, but little investigated
– Applied knowledge: remove or enhance natural flower
resources and on which scale?
Crop pollination and changing
landscapes
• Semi-natural elements rich on nesting and
flower resources are getting scarcer
throughout Europe
– a bit slower in Norway, but cultivated landscapes
are turning into forest or intensified
Practise I
• Honey bees are used, but in
varying degree depending on
beekeeper abundance
• Wild pollinators are relatively
abundant
– andplantations are relatively
small
– tunnels (raspberry) is a potential
challenge for some pollinator
species?
Practise II
• Apple producers often remove
dandelion and other (flowering)
vegetation to avoid competiton for
bees (and resources)
– Free, J.B. (1968) Dandelion as a
competitor to fruit trees for bee visits.
Journal of Applied Ecology, 5, 169-177.
• Also common to remove flowering
resources within plantings of other
fruits and berries
Scale-dependent effects of floral
neighbourhood
Hegland, S.J. (2014) Floral
neighbourhood effects on
pollination success in red
clover are scale-dependent.
Functional Ecology, in press
Scale-dependent effects of floral
neighbourhood
• Facilitation of visitation to red
clover at small scale changing to
competition at intermediate scale
and facilitation again at larger scale
• Methodologically challenge:
measure flower abundance at
different spatial scales
• Also: one need precise hypothesis.
– In this study only facilitation/
competition by density of similar
couloured flowers
Hegland, S.J. (2014) Floral neighbourhood effects on
pollination success in red clover are scale-dependent.
Functional Ecology, in press
Summing up
• Norwegian Fjords: a potentially interesting natural
climate laboratorium
– in itself and in relation to other areas with distinct climate
gradients
– requires high quality study-design and thought-through
experiments along climate gradient(s)
• Both climate and landscapes are changing in these
areas
– both potentially positive and negative effects of climate
– knowledge on climate change effects are scarce
– knowledge on effects of management of surroundings and
landscape change are scarce

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