Population Growth and Resource Availability · 种群增长与资源可获得性
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| limiting factor/ˈlɪmɪtɪŋ ˈfæktə/ | 限制因素 | xiàn zhì yīn sù |
Growth depends on resources
- How fast a population grows depends on what is available.
- With plenty of food and space, numbers explode.
- When resources run short, growth slows to a halt.
- Two curves describe these two situations.
增长取决于资源
- 一个种群增长多快,取决于有什么可用。
- 有充足的食物和空间,数量就爆发。
- 当资源短缺,增长就减慢到停止。
- 两条曲线描述这两种情况。
Exponential growth: the J-curve
- With unlimited resources, a population grows exponentially.
- Each generation adds more individuals than the last.
- Plotted over time, this makes a J-shaped curve that steepens.
- But no real environment offers unlimited resources for long.
指数增长:J 形曲线
- 有无限资源时,一个种群指数增长。
- 每一代增加的个体都比上一代多。
- 随时间画出来,这形成一条越来越陡的 J 形曲线。
- 但没有真实的环境能长期提供无限的资源。
With unlimited resources, a population grows… · 有无限资源时,一个种群……增长。
With no limits, growth is exponential · 指数 — a J-shaped curve that gets ever steeper. · 没有限制,增长是指数的——一条越来越陡的 J 形曲线。
Logistic growth: the S-curve
- As resources run short, growth slows.
- This turns the J-curve into a logistic S-curve.
- The population levels off at the carrying capacity, K.
- Real populations usually follow this S-shaped pattern.
逻辑斯谛增长:S 形曲线
- 当资源短缺,增长减慢。
- 这把 J 形曲线变成逻辑斯谛的 S 形曲线。
- 种群在环境容纳量 K 处趋平。
- 真实的种群通常遵循这个 S 形模式。
Exponential then logistic growth · 先指数后逻辑斯谛增长
J-curve, then S-curve at K · J 形曲线，然后在 K 处变为 S 形曲线
With unlimited resources growth is exponential (J); with limits it becomes logistic (S), leveling at K. · 资源无限时增长是指数的(J);有限制时它变成逻辑斯谛的(S),在 K 处趋平。
When resources become limited, growth becomes… · 当资源变得有限时,增长变成……
Limited resources turn exponential growth into logistic · 逻辑斯谛 growth, which levels off at K. · 有限的资源把指数增长变成逻辑斯谛增长,它在 K 处趋平。
Anything that slows population growth, like scarce food, is a ____ factor. · 任何减慢种群增长的东西,比如稀缺的食物,是一个____因素。
A limiting factor (food, water, space, disease) restricts how large a population can grow. · 一个限制因素(食物、水、空间、疾病)限制一个种群能长多大。
Limiting factors
- A limiting factor 限制因素 is anything that slows or caps growth.
- Food, water, space, and disease are common limiting factors.
- More resources raise the carrying capacity, allowing a larger population.
- Fewer resources lower it, forcing the population down.
限制因素
- 一个限制因素(limiting factor)是任何减慢或封顶增长的东西。
- 食物、水、空间和疾病是常见的限制因素。
- 更多资源提高环境容纳量,允许更大的种群。
- 更少资源降低它,迫使种群下降。
More available resources generally allow a population to grow larger. · 更多可获得的资源通常允许一个种群长得更大。
Abundant resources raise the carrying capacity, letting the population grow larger before leveling off. · 丰富的资源提高环境容纳量,让种群在趋平前长得更大。
Select all · 所有 true statements about population growth. · 选出关于种群增长的所有正确说法。
Real growth cannot stay exponential forever — resources run out. The other three are correct. · 真实的增长不能永远保持指数——资源会用尽。其余三条正确。
Exponential (J-curve) growth cannot last. It looks unstoppable, but every environment has limits. Sooner or later a limiting factor — food, space, disease — slows the growth into a logistic S-curve. A J always bends into an S in the real world.
指数(J 形)增长不能持续。它看起来势不可挡,但每个环境都有极限。迟早一个限制因素——食物、空间、疾病——把增长减慢成逻辑斯谛的 S 形曲线。在真实世界里,J 总会弯成 S。
Bacteria in fresh nutrients:
- Drop bacteria into a dish full of food: they grow exponentially, a steep J-curve.
- As the food runs low and waste builds up, growth slows.
- The population levels off at the carrying capacity — the J-curve has become an S-curve, limited by resources.
新鲜养分里的细菌:
- 把细菌放进一个满是食物的培养皿:它们指数增长,一条陡峭的 J 形曲线。
- 随着食物变少、废物积累,增长减慢。
- 种群在环境容纳量处趋平——J 形曲线变成了 S 形曲线,受资源限制。
Population growth depends on resources. With unlimited resources, growth is exponential (a J-curve); with limits, it becomes logistic (an S-curve) that levels off at the carrying capacity. A limiting factor — food, water, space, disease — slows growth, and more resources allow a larger population.
种群增长取决于资源。有无限资源时,增长是指数的(一条 J 形曲线);有限制时,它变成逻辑斯谛的(一条 S 形曲线),在环境容纳量处趋平。一个限制因素——食物、水、空间、疾病——减慢增长,而更多资源允许更大的种群。