Higher Tier: environmental change shifts distributions
הוצג| English | משמעות |
|---|---|
| distribution/ˌdɪstrɪˈbjuːʃn/ | התפלגות |
| range boundary/reɪndʒ ˈbaʊndəri/ | גבול תפוצה |
What would explain this observation?
- Higher Tier: A species recorded farther north after warming provides a distribution 分布 pattern, but surveying more northern sites could also change the record.
Build the model
- Environmental changes affect where species can survive and reproduce.
- Temperature, available water and atmospheric gas composition may change seasonally, across geographic locations or through human activity.
- A factor can move conditions outside a species’ suitable range, while making a different location more suitable.
- distribution: The locations where a species occurs.
- range boundary 分布边界: The mapped limit of a species’ occurrence in the supplied record.
What additional information best supports a long-term distribution comparison?
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
Long-term comparison needs like-for-like data: the same areas, seasons and methods at both times. One sighting or one individual's mass cannot represent a shifting distribution.
Match each technical term to its precise meaning.
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- Distribution is where organisms occur; abundance is how many occur.
- A geographic shift need not mean total population size increased.
- Evaluate whether records cover comparable seasons, sampling methods and areas.
- Competing species, dispersal barriers and habitat availability can alter the expected response to an abiotic change.
In the lab: Map supplied presence records with coordinates or distances and compare like-for-like surveys. Explain a plausible mechanism using the stated species requirements, then identify alternative factors. Include uncertainty from detection, short records and incomplete coverage. Do not turn an association into a universal migration prediction.
Which two habits make the investigation or model in this case more defensible?
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
Stating the conditions and assumptions lets others repeat the work exactly, and recording the supporting evidence lets them check the conclusion. Hiding disagreeing results removes the evidence that could challenge a wrong conclusion, and one measurement can never establish a wider claim.
Work from known quantities
- Known: a fictional northern range boundary changes from 200 to 245 km from a reference point over 15 years.
- Shift = 45 km; mean boundary-shift rate = 3 km/year.
- This is a mapped range statistic, not the travelling speed of an individual animal or proof that every year changed equally.
Your turn: A boundary shifts 60 km over 20 years. Calculate its mean shift rate.
A boundary shifts 60 km over 20 years. Calculate its mean shift rate.
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
The result is 3 km/year. Known: boundary shifts 60 km over 20 years. Mean shift rate = 60/20 = 3 km per year. This is a range statistic, not the speed of any animal.
Check the conclusion and its limits
- The same environmental change does not benefit every species.
- A distribution boundary is not an individual’s movement path.
- A seasonal record and a long-term geographic trend are different comparisons and should not be mixed without explanation.
Not true: Range-boundary shift rate is the speed of an individual organism. The boundary is a property of the whole population's mapped range, moving slowly as conditions shift. Individual animals move kilometres per day - a completely different quantity.
- Environmental changes affect where species can survive and reproduce.
- Distribution is where organisms occur; abundance is how many occur.
- Watch for: the same environmental change does not benefit every species.
The boundary is a property of the whole population's mapped range, moving slowly as conditions shift.
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
True. The boundary is a property of the whole population's mapped range, moving slowly as conditions shift. Individual animals move kilometres per day - a completely different quantity.
The locations where a species occurs: write the technical term.
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
distribution means The locations where a species occurs.