Pollination Flashcards
How many species of pollinators worldwide?
> 20 000 pollinators
What % of plants benefit vs are dependant on pollination from pollinators?
- 70% of most important crops benefit and 35% of agricultural production pollination-dependant
Name some crops that are really dependant on pollination (US$)
Apple
Almond
Cacao
What is self-pollination? What are some advantages and disadvantages?
When pollen from the same plant individual arrives at the stigma
- Advantage: preserves beneficial genotype
- Disadvantage: no adaptation potential
What is cross-pollination?
Pollen is delivered to stigma of another plant individual of same species
- Advantage: genetic mixing, adaptation
- Disadvantage: dependence on abiotic or biotic (animal) vectors
What is an advantage/role of wild bees in pollination of orchards?
- Wild pollinators facilitate between-row movement of honey bees
- Synergistic effects of non-Apis bees and honey bees for pollination
How many species of bees in Germany? How many are on the German Red List
570 species
53%
How does climate change affect honey bees?
Warm winters: honeybees become active too early: lack of foraging resources
Wild bee responses to warmer winter temperatures vary: bees overwintering as adults fly earlier, larval bees emerge later (response diversity)
Plant and pollinator responses may differ : loss of synchrony
Weather extremes increases risks of population extinctions
=> Habitat and resource specialists are most threatened
What are some drivers of colony collapse disorder?
- Varroa parasitic mites= most important parasite
- Pathogens
- Loss of nesting and flowering resources
=> Pesticides: including Neonicotonoids-> lethald dose vs sublethal effects ( bee not dying, but negatively affected)
- Neonicotinoids are linked with homming failure in honey bees and reduced queen production in bumble bees
Since when are neonicotinoids banned in the EU?
2018
What are some results of a field study on neonicotinoid effects on wild bee reproduction?
Study in Sweden 8 paired landscapes, oil seed rape fields with coated vs untreated seeds.
When seed coated:
- Decreased density of wild bees
- Significant decrease in tubes with nesting
- Less bumble bee cocoons
- Also less bumblebee colony development weight change
=> Insecticide application= high risk for wild bees in agricultural landscapes
How does organic and convetional differ when considering pollination?
Organic farming enhances crop pollination services regarding both yield quantity and fruit quality in strawberries
How do wild bees affect differently pollination vs honey bees?
Wild bees=> increase cross pollination in apple orchard
Crop yield increases always with wild pollinators, but with honey bees in only 14% of all cases (meta-analysis with 41 crop species across 200 countries in 2013)
=> wild and honeybees act indeendently
==> higher diversity of pollination was associated with higher seed production in pumpkins (not the number of visits, but number of guilds in this study in Indonesia)
- The higher number of guilds, the more seeds
Give examples of how and why bee diversity is important
ex of bee abundance in strawberry fields with adjacent oilseed rape flower cover
=> Solitary bee facilitated vs honeyees and bumblees distracted
Bee diversity increase coffee yield. Forest near is really important => diversity of landscape. Closer to natural forest=> higher yields
The higher the distance with natural habitat=> decrease visit from wild pollinators
What other animal is important in pollination?
Bats
-> durian fruit pollination.
-> economically really important in south east asia
