lecture 24- impacts of anthropogenic climate change on ecosystems 1 Flashcards
How will climate change impact ecosystems in terms of self, time, and space?
Self: changing life history traits in terms of your physiology.
Time: adjusting life cycle events to match the new climatic conditions.
Space: dispersing to areas with suitable habitat.
What is phenotypic plasticity?
The ability of a single genotype to produce alternate phenotypes in an environmentally dependent context.
It is a fundamental mechanism by which species respond to a changing environment.
What is the physiological adaption to climate change for plants?
The optimal temperature for CO2assimilation was strongly correlated with daytime temperature. As the temperatures increases, their favorite temperature can increase with it - they are not negatively affected.
Direct impacts of climatic warming on forest productivity, species survival, and range limits may be less than predicted.
What is the physiological adaption to climate change for invertebrates?
Populations with different thermal histories (cool vs. warm), compared physiological adjustments following exposure to warming.
Warm-acclimated individuals had a higher thermal threshold. The ones from warm environments had higher critical temperatures (beyond a point, it is critical), so they dealt with climate change better.
Given the relatively gradual rate of global warming, marine organisms may be able to adaptively adjust their physiology to future climate.
What is the physiological adaption to climate change for fish?
Warmer waters could lead to smaller fish.
- Warmer water contains less oxygen.
- Fish require more oxygen at higher temperatures.
- Since fish are ectotherms (cold-blooded), their metabolism is sensitive to temperature – and increases rapidly with temperature. - Larger fish cannot compensate when oxygen declines.
What is the Gill-Oxygen limitation theory? What does it affect?
The growth of gill surfaces cannot keep up with the oxygen demand of growing 3-dimensional bodies.
Gill surface area does not increase in constant proportion with fish body weight. Fish size is constrained by the capacity to take up O2. When [O2]declines, the fish size must decline.
What is the physiological adaption to climate change for birds?
Increased bill size in response to climate change has been shown in 23 bird species because of Allen’s rule.
What is Allen’s rule?
Allen’s rule: appendages of endotherms will be larger in warmer climates - dumping of heat loads. The warmer the temperatures, the bigger the appendage because it is trying to get rid of the heat.
Mammals: larger tail, ears, legs.
How are reptiles affected by climate change?
Activity in hot weather may result in body temperatures exceeding the critical thermal maximum, leading to death.
What is the physiological adaption to climate change for reptiles? What were the consequences?
Retreat to cool refuges rather than risk death by overheating - they spend their lives hiding in the shade.
However, in thermal refuges limited foraging decreased growth, maintenance, and reproduction.
Phenotypically plastic adjustments to thermoregulatory behavior increased their vulnerability to extinction.
What is the physiological adaption to climate change for polar bears (mammals)?
Polar bears use sea ice to hunt, but ice levels are decreasing due to climate change.
They started to eat more and more on land since they can’t hunt the fish in the water. Polar bears can and have eaten caribou, geese, rodents, and grazed vegetation.
This led to decreases in body condition (lose weight) and survival rates
What is phenology?
The study of recurring plant and animal life cycle stages that are influenced by environmental changes, especially seasonal variations in temperature and precipitation driven by weather and climate.
Has been principally concerned with the dates of the first occurrence of biological events in their annual cycle.
How is climate change affecting phenological adaptation?
Life events are happening earlier in the year.
The advance in phenology is 3x stronger in birds & butterflies than in flowering plants…
What are the phenological adaptions to climate change for birds?
Changed their egg-laying date- they lay their eggs earlier and earlier as temperatures increase.
What are the phenological adaptions to climate change for butterflies (insects) ?
Butterfly migration timing is earlier and reduced population size.
Causes = deforestation, climate change, loss of milkweed.
