ECOLEC CHAPTER 3: INTRASPECIFIC POPULATION REGULATION

Indefinitely

No population continues to grow ____________

Competition

When organisms utilize a shared resource that is scarce, this occurs.

Intraspecific competition

Competition between the same species is called

Scramble competition, Contest competition

What are the 2 responses of a population when resources are limited

Scramble competition

This competition occurs when growth and reproduction decreases equally across individuals in a population as the intensity of competition increases.

Contest competition

This competition occurs when some individuals receive enough or ample resources while refusing to share

Competing individuals

These individuals do not often interact directly with one another

Exploitation

Competition is referred to as?

Interference

This is referred to when individuals actively engage with others to protect their resources

Growth and development

What is first affected by intraspecific competition?

Population density rise

A decrease in resource intake will be seen as?

Malnutrition, Stunted growth, population decline

In both plants and animals, scarcity can lead to?

Density-dependent growth

When observed in a graph, an inverse relationship between growth rate and population density can be inferred, described as

J.N. Chatworthy

Who conducted the study on white clover plants that revealed the direct consequences of resource limitations in a population

Low densities

All individuals are able to obtain enough resources to meet growth demands at ?

Decrease in plant size and growth rate

when the number of individuals planted in a pot increases, the demand for resources in the pot often surpasses the supply, resulting in a decrease in both

Phenotypic characteristics

In intraspecific competition, it was observed that there was an increase changes in what characteristics of organisms?

Environmental factors

These greatly affect population growth because environmental elements limit growth through both competition and mortality rates.

Increased

When humans increase in population, demands for resources such as food, water, and energy are _________ and Competition becomes fierce due to resource scarcity

High-population areas

These areas tend to allow diseases to spread widely because living conditions are so close together that transmission occurs in record time, further raising the rate of mortality in outbreak times.

Overpopulation

This leads to environmental degradation, which entails reduced biodiversity and ecosystem health

Human Mortality Risks

the losses of habitats for humans to carry out urbanization and agriculture reduce the human resources thus creating a feedback, where with declining ecosystem health arises what?

People

Pollution and waste multiply with more?

Resource depletion and climate change

Although health and medical sciences have been improving mortality rates globally, the uninhibited growth of populations and their deleterious effects may actually contribute to high mortality through

Environmental factors

These restrict population growth through resource scarcity, competition, transmission of disease, and climate change

Population growth

This is a complex phenomenon influenced by a multitude of factors, with the environment playing a pivotal role.

Environment

This provides the necessary resources for survival and reproduction, but these resources are often limited.

Carrying capacity and Resource limitation

The carrying capacity of an environment represents the maximum population size that a particular ecosystem can sustainably support. This competition can lead to a decrease in reproductive success, as individuals struggle to secure the resources necessary for breeding and raising offspring

Intraspecific Competition and Reproduction

A competition between individuals of the same species, plays a crucial role in regulating population growth

Food Scarcity, Nesting Site Competition, Mate Competition

Competition can manifest in various ways, directly impacting reproduction

Food Scarcity

When food resources become limited, individuals may experience reduced breeding rates, smaller litter sizes, or even the inability to reproduce at all. This is particularly evident in species with high dietary requirements or those that rely on specific food sources

Nesting Site Competition

Species that require specific nesting sites, such as birds or certain insects, may find it difficult to reproduce if these sites are limited or already occupied. This competition can lead to delayed breeding, smaller clutch sizes, or even the abandonment of nesting attempts.

Mate Competition

Competition for mates can reduce the number of successful breeding pairs, ultimately affecting the population growth rate. This competition can take various forms, including displays of dominance, territoriality, or elaborate courtship rituals.

Environmental Factors and Reproductive Strategies

The environment also influences the evolution of different reproductive strategies. Species inhabiting harsh environments, characterized by limited resources and unpredictable conditions, often exhibit strategies like producing a large number of offspring with a low survival rate

Home Range

This term refers to the area that an animal uses on a regular basis throughout the year

Body Size

Home range size is proportional to what? which also emphasizes the relationship between body size and energy requirements

Territory or Defend region

If the animal defends any section of its home range, we refer to it as a?

Territorial Behavior

The number of people who can occupy a given area can be limited by this kind of behavior and it also slows down population growth

Territoriality

This is essential as a density-dependent feature, including competitiveness

Well-defined Behavioral patterns

song and call, intimidation displays such as expanding wings and tail in birds and baring teeth in mammals, attack and chase, and marking with odors that trigger escape and avoidance in rivals.

Evic extra individuals

When the available area is full, owners _____ _____ ___________, denying them access to resources and possibe mates

Space and resources

As population rise, competition for these intensifies

Population size and density

These are the two most important statistics scientists use to describe and understand populations

Population Size

This refers to the number of individuals (N) it comprises.

Density

This is the number of individuals within a given area or volume.

Larger Population

Density affects greatly towards a population that is more stable

Larger Population

Which is more stable? Larger population or smaller population?

Less genetic variation

Due to this problem, smaller populations will have a reduced capacity to adapt to environmental changes

Mate

Individuals in a low-density population are thinly dispersed; hence, they may have more difficulty finding a what?

Competition for food

In high-density populations, it often results into an increased in?

Higher population densities

Many factors influence density, but, as a rule-of-thumb, smaller organisms have?

Regulatory factor

In ecology, a density-dependent factor, also known as a

Regulatory Factor

This is any force that influences the size of a population of living creatures in response to population density (the number of individuals per unit area).

Biological events

Rather than physical or chemical phenomena,Rather than physical or chemical phenomena, what are frequently the source of density-dependent variables?

Biotic

The majority of density-dependent limiting variables are

Competition, Predation, Infections and Parasites, Build-up of waste

These are some instances of density-dependent limiting factors

Competition

When a population reaches a high density, more organisms compete for the same limited resources. Competition for food, water, shelter, mates, light, and other resources required for life and reproduction might occur

Predation

Predators may attract higher-density populations that would not bother with a sparse population. When these predators devour population members, they reduce the population’s size while potentially increasing their own. This can result in cyclical patterns that are intriguing to look at.

Infections and Parasites

When more people live in the same location, the disease is more likely to spread and result in mortality. In these settings, parasites are also more prone to spread.

Build-up of waste

High population densities can lead to the build-up of toxic waste products, killing individuals or making reproduction difficult, limiting population increase

Behavioral or physiological changes

These changes in the creatures that make up the population can also be examples of density-dependent control. Density-dependent regulation can also take these forms in the organisms that make up the population