Plant Ecology and Temperate Deciduous Forests

Temperate Deciduous Forest Overview

• Found in moderate climates
• Dominated by hardwood deciduous trees
• Key characteristics include: four distinct seasons, nutrient-rich soils from annual leaf fall, moderate precipitation and temperature promote decomposition, high biodiversity compared to boreal forests
• Seasons and climate: spring has understory sunlight due to leafless trees, summers are warm, winters are cold and snowy, precipitation is moderate and evenly distributed throughout the year
• Biodiversity includes producers (primarily plants, trees being the main focus), consumers (numerous birds and small mammals, larger mammals are grazers and carnivores/scavengers), and decomposers (fungi and invertebrate such as insects, worms, gastropods, crustaceans, nematodes)
• Fallen plant material enriches the soil throughout the year
• Tree species are of mixed age and species
• Deciduous trees drop their leaves in winter. Examples include maple, oak, beech, and elm.
• Coniferous trees retain leaves throughout the winter. Examples include red and white pine, hemlock, and white cedar.
• Ontario's Great Lakes-St. Lawrence Forest Zone is a mix of deciduous and boreal forests with varied tree species. There is a transitional nature in the species present
• Historical impact involves heavy logging during colonization.

Plant Evolution and Land Plants

• Land plants evolved approximately 470 million years ago from green algae.
• Early challenges include the method of obtaining water from soil and limited capacity to restrict water loss.
• Phylogeny of land plants is shown by a Monophyletic group descended from green algae. The groups are Bryophytes (non-vascular plants) and Vascular Plants (Tracheophyta).

Vascular Plants (Tracheophyta)

• Synapomorphy: Presence of vascular tissue (xylem and phloem)
• Four key groups of vascular plants include Lycophytes, Ferns, Gymnosperms, and Angiosperms.
• Vascular tissue extends from roots to leaves.
• Vascular tissue is organized in rings near the stem's exterior
• Xylem carries water and minerals from roots to leaves. Structure includes hollow conduits with lignin for support.
• Phloem carries photosynthates from leaves to roots, including carbs, amino acids, nitrogen, ions, hormones, and RNA. The nucleus and cytoplasm are lost during development.

Tree Growth and Structure

• Primary growth increases height and length.
• Secondary growth increases diameter via vascular cambium by producing new xylem and phloem.
• Growth rings show seasonal differences in xylem (wood) cell size.

Gymnosperms vs. Angiosperms

• Both are seed-producing vascular plants.
• Gymnosperms have seeds developing on cones, are pollinated by wind, and examples include pines, yews, junipers, and cedars.
• Angiosperms have seeds developing within fruits and are pollinated by wind, water, or animals. Examples include diverse flowering plants.

Seed Dispersal Mechanisms

• Gymnosperms' seeds fall to ground or are wind dispersed with specialized structures.
• Angiosperms use fruits to aid in dispersal by animals or wind

Pollen and Reproduction

• Gymnosperms are wind-pollinated, and Angiosperms are pollinated by wind, animals, or water.
• Gymnosperms' seeds develop on cones, while Angiosperms' seeds develop within fruits.

Key Concepts in Plant Lifecycle

• Plants alternate between haploid and diploid phases (both phases undergo mitosis).
• Seed plant life cycle is dominated by a diploid (2n) stage. Gametes are pollen (male) and ovule (female). A zygote develops into an embryo within the seed.

General Characteristics of Birds

• About 10,000 bird species globally
• Bipedal vertebrates with feathers, toothless beaks, complex behaviors, and adapted forelimbs.
• Specialized bills adapted for diverse diets
• Categories include Palaeognathae (large flightless birds), Galloanserae (e.g., Galliformes- pheasants), and Neoaves (modern birds).

Mammals (Mammalia)

• Key traits: Hair, mammary glands, internal fertilization, warm-blooded, and care for young until independence.
• Have hair made of keratin. Specialized hairs include vibrissae (whiskers) and porcupine quills.
• Specific Mammalian species in temperate deciduous forests include rodents (e.g., porcupines, chipmunks), deer (herbivores), and mammals that hibernate.

Top Consumers (Raptors)

• Examples include hawks, eagles, falcons, and owls.
• Diet is carnivorous or scavenging on smaller animals.
• Traits include excellent eyesight, talons, and curved beaks.

###Lower Consumers: Songbirds • ~3,000 species, use complex songs for communication and territory. • Sexual dimorphism: Females are often dull-colored for predator evasion. • Diet includes insects, invertebrates, fruits, nuts, seeds. • Predators are birds of prey and mammals. Woodpeckers are birds that are specialized feeders.

Reptiles Overview

• Ectothermic (depend on environmental heat sources).
• Lay shelled eggs (oviparous), and some are ovoviviparous or viviparous.
• Sensitive, with poor eyesight and hearing.
• Examples in temperate forests include snakes.

Amniotes

• Key characteristics include shelled eggs, preventing moisture loss.
• Eggs have adaptations such as outer shells.

Fungi

• More closely related to animals than plants.
• Key traits: Produce chitin, are heterotrophic, and reproduce both sexually and asexually.
• Important ecological roles include carbon cycling and interactions with plants

Urban Landscapes

• Urban areas are full of life but are typified by disturbance.
• Characterized by human-propagated plant monocultures with both native and non-native species coexisting.
• Urban organisms face significant pressures including pollution, physical barriers (pavements), and human interaction.
• City areas are generally 10-15 degrees warmer than rural areas.
• Various organisms show adaptation in different ways, including avoidance

Urban Flora and Fauna: Plants

• Desirable plants include trees, grass, and ornamental flowers, while weeds are less desirable.
• Successful plants in urban areas often grow quickly from seed and tolerate high levels of nutrients and toxic contaminants.
• Lichens are composite organisms consisting of fungi/yeast and cyanobacteria/green algae. They are often found in extreme habitats like bare rocks and the arctic.
• Earthworms contribute to nutrient cycling in urban areas by breaking down matter and mixing the soil.
• Insects are a diverse group in urban areas.

Urban Flora and Fauna: Animals

• Urban animals often adapt via avoidance, exploitation, or adaptation. Examples include: Raccoons, red foxes, pigeons, rats.

Life History Trends in Urban Birds

• Urban birds show trends towards smaller body size, broader dietary and habitat niches, longer lifespans, and are often not as territorial. Common urban birds include feral pigeons, house sparrows, barn swallows, and others.
• Example of the Peregrine Falcon, fastest animal on Earth, showing adaptations in hunting for urban prey.
• The urban carnivore, bobcat, shows adaptability to urban environments, but it encounters challenges like road barriers and exposure to disease. The domestic cat may become an invasive species in many ways, including population overgrowth and impacting other species.

Urban Management Strategies

• Wildlife underpasses or corridors to facilitate gene flow between fragmented populations.
• Urban areas create pressures to various species through pollution and physical barriers like pavement.

Coral Reefs Overview

• Important geological structures in marine habitats.
• Show high biological diversity. Provide shoreline protection, harbors, fishing, and tourism.
• Composition is primarily of coral, coralline algae, sponges, and other organisms cemented together.
• Coral growth relies on several factors for the reefs to thrive.

Coral Reef Structure and Growth

• Reef-building corals belong to the Order Scleractinia (Stone Coral).
• Corals have skeletons of calcium carbonate
• Colonies of similar polyp organisms are interconnected by cenosarc tissue with each polyp within the cenosarc tissue able to regenerate asexually
• Coral growth forms are encrusting, massive, branching, and foliaceous which are influenced by growing conditions
• Growth rates are significantly variable.

Coral Growth Factors and Limitations

• Coral thrives in several environmental requirements such as average salinity (around 35ppt), surface temperatures higher than 20°C, high light levels for symbiosis, and low turbidity with weak currents.
• Challenges impacting corals include ocean acidification, sea-level change, competition from bioerosion, overfishing, and pollution. Various types of reefs exist in different areas, such as shelf reefs, oceanic reefs (fringing reefs, barrier reefs, atolls).
• Coral reefs have different ways of reproduction, such as asexual or sexual reproduction which depends on species.
• Natural disturbance from hurricanes and storm waves can lead to significant mortality.

Coral Reef Decline and Threats

• Natural disturbances, such as hurricanes and large storm waves, can significantly affect coral reefs.
• Man-made disturbances have a large impact including coastal development and the runoff from agriculture. Factors such as pollution and sedimentation also cause significant damage to coral reefs.
• Coral bleaching is caused by several factors such as temperature stress, disease, and expulsion of zooxanthellae.
• Global warming is now causing over 50% loss of coral over the last century

Coral Reef Fisheries and Diversity

• Coral reefs support diverse fish species. Fish play a large role in roles like feeding and reproduction for the reef.
• Overfishing leads to dramatic decreases and a possible transition to algae dominated ecosystems which are at risk of overfishing (around 60%).

Freshwater Biomes

• Freshwater biomes include lakes, rivers, and streams.
• Lakes are considered lentic (still water) while rivers and streams are lotic (moving water).
• Differences exist in characteristics including climate and topography factors influencing nutrient input and oxygen availability.

Characteristics of Rivers and Streams

• Rivers and streams are defined by moving water.
• Size and chemical composition of waters vary dramatically, and are influenced by terrain, runoff, rain, and groundwater.
• Nutrient levels in these water systems range from low to extremely high, with sources like rain and runoff.
• River conditions are affected by light quality, sediment movement, nutrients, oxygen levels, and other factors.

Producers in Streams

• Primary producers in streams include photosynthetic organisms such as large/small plants and algae along margins and phytoplankton in the water column.
• Key phytoplankton groups include cyanobacteria and eukaryotic algae (green algae like chlorophylls a, b; carotenoids; starch storage, and cell wall components of cellulose and pectin), and stramenopiles (diatoms)

River Consumers and River Composition

• Key consumers in rivers include insects, other invertebrates (crustaceans and shellfish), and vertebrates (fish).
• Microhabitats in rivers reflect the non-linear nature of stream flow from pools, runs, riffles, and rapids which influence various water column, benthos, and riparian zones (areas transitioning between land and river).

Ecological Processes and Human Impacts on Rivers

• Natural sources for nutrient cycling in rivers are weathering and erosion, while human-made sources include urban and agricultural runoff, and wastewater discharge.
• Excess nutrients can cause eutrophication and oxygen depletion.
• High biological oxygen demand (BOD) points to high organic pollution leading to oxygen stress for freshwater aquatic organisms.
• Human activities like climate change impact water temperature and oxygen levels creating alteration to flow patterns, affecting the distribution of sediment and nutrients.

Freshwater Animals as Indicators of Environmental Disruption

• Many amphibian species are threatened with extinction, in part due to habitat loss, pesticides, and fungal diseases.
• Pollution from various sources including construction, agriculture, and road salt can significantly impact freshwater biodiversity.
• Studying these living organisms provides insights into the health of the habitat and how they are reacting.

Biodiversity Loss and Conservation Biology

• Diminished biodiversity has negative effects on resilience and new discoveries (medical, industrial).
• Humans depend on biodiversity and areas with high indigenous richness are under conservation priorities.

Subphylum Vertebrata (Craniata)

• Vertebrates are a prominent subphylum of the Animal Kingdom characterized by a cranium enclosing the brain, and endoskeletons made of cartilage or bone.
• The evolution of bone provides increased structural support compared to cartilage and is crucial for the attachment of muscles and movement

Teleost Fishes (Class Actinopterygii)

• Teleost fishes account for 96% of all living fish species.
• Found in diverse environments (high altitudes to deep ocean depths)

Transition from Bony Fishes to Tetrapods

• Key adaptations for transition include bone replacing cartilage as the skeletal structure and the evolution of lungs, double circulation, and adaptations for limbs and land movement.