Chapter 52 - An Introduction to Ecology and the Biosphere

The tilted axis of rotation of the Earth and its yearly journey around the sun create substantial seasonal variations in day length, solar radiation, and temperature in the medium to high latitudes.

The shifting angle of the sun throughout the year has an impact on local ecosystems. For example, when the sun's angle changes, the belts of wet and dry air on either side of the equator migrate somewhat northward and southward, resulting in distinct wet and dry seasons about 20° north and 20° south latitude, where many tropical deciduous kinds of wood thrive. Furthermore, seasonal variations in wind patterns affect ocean currents, forcing cold water from deep ocean layers to rise.

Ocean currents affect climate along continents' coasts by heating or cooling overlying air masses that travel overland. Coastal locations are also wetter than upland places at the same latitude. The cold creates a chilly, foggy atmosphere.

California The current that flows southward throughout western North America sustains a coniferous rain forest environment over much of the continent's Pacific coast, as well as huge redwood forests further south.

The west coast of northern Europe, on the other hand, has a moderate climate because the Gulf Stream transports warm water from the equator to the North Atlantic.

As a result, northern Europe is warmer in winter than southeastern Canada, which is further south.

Because climatic factors influence the geographic ranges of the majority of plants and animals, every large-scale change in the Earth's climate has a significant impact on the biosphere.

Indeed, a large-scale climate "experiment" is currently underway: The use of fossil fuels and deforestation raise the levels of carbon dioxide and other greenhouse gases in the atmosphere. This has resulted in climate change, which is a directional shift in the global climate that lasts three decades or longer (as opposed to short-term changes in the weather).

The Earth has warmed by an average of 0.9°C (1.6°F) since 1900 and is expected to warm another 1–6°C (2–11°F) by the year 2100.

The attached image shows the current range and predicted ranges for the American beech under two climate-change scenarios.

The microclimate, or very tiny, localized patterns in environmental conditions, exists on an even smaller scale. Many environmental factors impact microclimate by throwing shadows, influencing soil evaporation, or changing wind patterns. Forest trees, for example, frequently regulate the microclimate underneath them.

Because of the increased solar radiation and wind currents caused by the fast heating and cooling of open ground, cleared regions generally endure higher temperature extremes than the forest interior.

Low-lying land in a forest is typically wetter than higher ground and is inhabited by a variety of tree types. Salamanders, for example, can find refuge in a log or huge stone.

The intake of solar energy and the Earth's movement around the sun has a major influence on global climate patterns.

The shifting angle of the sun throughout the year, bodies of water, and mountains all influence climate on a seasonal, regional, and local scale.

The microclimate is determined by fine-scale variations in abiotic (nonliving) elements such as sunshine and temperature.

Rising greenhouse gas concentrations in the atmosphere are warming the planet and changing the ranges of numerous animals. Some species will be unable to move their ranges rapidly enough in the future to find appropriate habitats.

Temperature and precipitation are associated with biomes, according to climate graphs. Biomes overlap because other variables influence biome placement.

Terrestrial biomes are frequently called for important physical or climatic elements, as well as the prevalent flora. Vertical layering is a characteristic of terrestrial biomes.

Disturbance, both natural and man-made, has an impact on the type of vegetation present in biomes. Humans have changed most of the Earth's surface, displacing the described natural terrestrial ecosystems.

The attached image shows interactions between organisms and the environment limit the distribution of species.

In deciding where biomes exist, the pattern of climatic fluctuation is just as significant as the average climate.

• The term Aquatic biomes refer to being varied and dynamic systems that cover the majority of the Earth's surface.

Aquatic biomes are distinguished largely by their physical environment rather than by climate, and they are frequently stratified in terms of light penetration, temperature, and population structure. The salt content in marine biomes is greater than in freshwater biomes.

An abrupt temperature shift known as a thermocline separates a more consistently warm top layer from more uniformly cold lower waters in the ocean and most lakes.

In the spring and fall, many temperate lakes experience water turnover, or mixing, which brings deep, nutrient-rich water to the surface and shallow, oxygen-rich water to deeper layers.