Review of D4.3 HL Phenology and Climate Change

A collection of vocabulary flashcards based on key concepts related to phenology and climate change discussed in the D4.3 HL lecture.

Phenology

The scientific study of the timing of recurring biological events (e.g., budding, flowering, migration) in organisms and their response to environmental factors like temperature, photoperiod, and precipitation. It is vital for understanding climate change impacts on ecosystems.

Bud

An undeveloped plant structure, typically protected by scales, containing embryonic shoots, leaves, or flowers. Buds are crucial for plant growth, differentiating into stems, foliage, or reproductive parts.

Bud setting

The physiological process in plants where dormant buds form, usually in late summer or autumn. This prepares the plant for winter or a new growth cycle, conserving energy and protecting meristematic tissue.

Buds bursting

The opening of a plant bud, driven by cell expansion and growth, revealing new leaves or flowers. This event is typically triggered by favorable environmental cues like increasing temperatures and longer photoperiods after dormancy.

Photoperiod

The length of daylight an organism experiences within a 24-hour cycle. It serves as a crucial environmental cue, influencing phenological processes such as flowering, migration, and dormancy.

Trophic mismatch

An ecological imbalance where the peak availability of food resources no longer aligns with the peak energy demand of consumers (e.g., herbivores or predators). Often worsened by climate change, this leads to negative consequences like reduced reproductive success and population declines.

Univoltine

Refers to organisms, typically insects, that complete only one generation or life cycle annually. Common in regions with limited suitable reproductive conditions, like temperate and polar areas.

Bivoltine

Refers to organisms, usually insects, that produce two generations or life cycles within a single year. This accelerated reproductive rate occurs in favorable environmental conditions, such as warmer temperatures, allowing for quicker development.

Reindeer migration

The annual, extensive movement of reindeer populations, primarily driven by changing photoperiod and secondarily by temperature. This migration is essential for finding optimal spring calving grounds and accessing seasonal, nutrient-rich forage.

Arctic mouse-ear chickweed

A resilient Arctic flowering plant crucial to the reindeer diet during calving season. Its blooming, cued primarily by temperature increases, is highly susceptible to climate change-induced phenological shifts and potential trophic mismatch with migrating reindeer.

Tawny owl

A common owl species with grey and brown color morphs. Climate change-induced milder, snow-free winters favor the brown morph, as it blends better with snow-free vegetation, leading to a survival advantage over the grey morph, which is better camouflaged in snowy environments.

Spruce bark beetle

An aggressive insect pest that tunnels under spruce bark, disrupting the tree's vascular system and often causing death. Warmer temperatures from climate change accelerate its reproductive cycle, leading to more generations per year (e.g., univoltine to bivoltine shifts), significantly increasing populations and forest damage.

Climate change

Significant, long-term shifts in global or regional climate patterns, including changes in average temperature, precipitation, and extreme weather. Primarily driven by human greenhouse gas emissions, it profoundly impacts phenology, biodiversity, and ecosystem stability.

What are the ecological consequences of trophic mismatch?

Trophic mismatch leads to severe ecological consequences, such as reduced reproductive success, decreased survival rates for all age groups, and population declines in affected consumers. These impacts can cascade through food webs, altering species interactions, community structure, and potentially causing local extinctions when synchronized relationships are disrupted.

How does climate change specifically lead to increased populations of spruce bark beetles?

Warmer temperatures due to climate change shorten the spruce bark beetle's life cycle, accelerating its development. This allows beetles to complete more generations annually (e.g., shifting from univoltine to bivoltine), exponentially increasing populations and leading to widespread destruction of spruce forests.

How does the timing mismatch between reindeer migration and the Arctic mouse-ear chickweed affect reindeer?

A timing mismatch severely impacts reindeer populations. Warmer temperatures trigger earlier blooming of Arctic mouse-ear chickweed, a vital food source. If reindeer migration, primarily daylight-cued, doesn't also advance, they miss the peak availability of this plant. This 'green wave' mismatch results in insufficient high-quality forage for lactating females and calves, leading to reduced maternal condition, lower calf growth and survival rates, and overall population decline.

Why does the grey morph tawny owl experience a survival disadvantage due to climate change?

The grey morph tawny owl experiences a survival disadvantage as climate change leads to milder, snow-free winters. Historically camouflaged in snowy environments, the grey morph becomes more conspicuous against bare ground and vegetation, increasing its predation risk and potentially reducing hunting success, especially compared to the brown morph which thrives in these snow-free conditions.