Ess 050 Final Exam Questions PDF

Multiple choice questions: Will cover Rivers, Sandy Beaches, Coastal Dunes, Chaparral, Coastal sage scrub, Coast redwood forests, Montane forests, Subalpine, Alpine, and Deserts. ​ Rivers​ Overview of California Rivers ​ Definition of a Watershed: ​ An area of land where precipitation...

Multiple choice questions: Will cover Rivers, Sandy Beaches, Coastal Dunes, Chaparral, Coastal sage scrub, Coast redwood forests, Montane forests, Subalpine, Alpine, and Deserts. ​ Rivers​ Overview of California Rivers ​ Definition of a Watershed: ​ An area of land where precipitation drains into a common body of water (stream, river, lake, ocean). ​ Defined by topographical features like ridges or high points separating drainage areas. ​ All land is part of a watershed. ​ Major Rivers and “our” river: ​ Sacramento River: Longest river in California; serves northern California. ​ San Joaquin River: Central and southern regions; merges with Sacramento River in the Sacramento-San Joaquin Delta. ​ Merced River: Located in the Sierra Nevada, designated as “Wild and Scenic” for its ecological and recreational value. Connections to California Ecosystems ​ Rivers distribute snowmelt and rainfall to forests, grasslands, wetlands, and urban areas. ​ Provide irrigation for agriculture. ​ Deposit nutrient-rich sediments in valleys and floodplains. ​ Transfer nutrients via processes like salmon spawning. ​ Contribute sediments to the ocean, supporting coastal ecosystems and beaches. Annual Flow Variations ​ River flow fluctuates with precipitation events and snowmelt. ​ High flows: ​ Bring large woody debris, enhancing structural habitat. ​ Scour riverbeds, maintaining fish habitats and clearing gravel for spawning. ​ Revitalize riparian vegetation, promoting biodiversity. Riparian Vegetation and Its Role ​ Willows and Riparian Plants: ​ Stabilize riverbanks and control erosion.  ​ Provide shade, regulating water temperature and improving oxygen levels. ​ Offer shelter and breeding grounds for wildlife like birds, insects, and amphibians. Salmon in California Rivers ​ Anadromous Life Cycle: ​ Born in freshwater, migrate to the ocean, return to spawn in their birthplace. ​ Keystone Species: ​ Support predators (bears, eagles). ​ Their carcasses provide nutrients for river ecosystems. ​ Challenges: ​ Dams block migration, disrupting ecosystems and threatening populations. ​ Major Species: Coho, Chinook, and Steelhead. Dams on California Rivers ​ Pros: ​ Reliable water supply for agriculture, cities, and industry. ​ Flood control. ​ Cons: ​ Habitat destruction upstream. ​ Block salmon migration, reducing biodiversity. ​ Trap sediments that replenish coastal ecosystems. Merced River Watershed ​ Features: ​ ~1,700 square miles in the Sierra Nevada. ​ Primarily fed by snowmelt (85% of flow). ​ Wild and Scenic Designation (1987): ​ Recognizes its free-flowing condition, water quality, and cultural significance. ​ Biodiversity: ​ Species: Chinook salmon, western pond turtle, Sierra newt, limestone salamander. ​ Iconic Plants: California poppy, western redbud, willows. ​ Human Modifications: ​ Dams like New Exchequer reduce flow and block anadromous fish migration upstream. Key Takeaways ​ Rivers are lifelines for California ecosystems, connecting mountains, valleys, and coastal regions.  ​ Riparian habitats and species like salmon are indicators of river health. ​ Human modifications like dams provide benefits but pose significant ecological challenges. ​ Protecting rivers, like the Merced River’s Wild and Scenic designation, ensures their ecological and cultural legacy endures. Sandy Beaches and Dunes Physical Features and Shapes of Beaches ​ Formation: Beaches are created by mobile sediments shaped by waves, wind, and tides. ​ Types: ​ Pocket beaches: Found in coves along rocky coasts (e.g., Point Lobos, Natural Bridges). ​ Delta beaches: Formed at river mouths (e.g., Mattole Beach, Redwood Creek Beach). ​ Logarithmic spiral beaches: Form downcoast of rocky points (e.g., Half Moon Bay, Bodega Bay). ​ Long Straight beaches: Aligned with wave direction, upcoast of rocky points (e.g., Salmon Creek Beach, Russian River). ​ Wide beaches with dunes: Found near rivers and backed by sand dune fields (e.g., Ten Mile River Beach, Guadalupe Dunes). Dynamic Nature of Beaches ​ Sand Movement: ​ Driven by littoral/longshore currents which flow parallel to the shore. ​ Sand moves in a “river of sand” along the coastline. ​ In California, dominant sand transport is north to south due to wave patterns. ​ Littoral Cells: ​ Defined coastal segments managing sediment movement. ​ Sources: Streams, rivers (80-95%), bluff erosion. ​ Sinks: Submarine canyons, sand dunes. ​ Examples: ​ Major sand sinks: Monterey Canyon. ​ Littoral cells ending in dunes: Ten Mile River cell, Navarro River cell. Sediment Budget and Erosion  ​ Sediment Budget: Balance of sand inputs (rivers, erosion) and losses (dunes, canyons). ​ Affects beach width and stability. ​ Human impacts: ​ Dams reduce sand supply. ​ Coastal armoring limits erosion but increases wave energy. ​ Beach nourishment widens beaches artificially. ​ Coastal Erosion: ​ Caused by sediment budget deficits, sea level rise, and human modifications. ​ Sandy beaches can erode in storms but rebuild during calm summer waves. Life on the Beach ​ Habitat Features: ​ Upper beach: Dry, sun-baked, wind-blown. ​ Lower beach: Wet, wave-pounded, intertidal. ​ No plants due to shifting sands; life is mobile and burrows during the day. ​ Ecosystem Roles: ​ Wrack (kelp and seagrass): Provides key organic material for food webs. ​ Primary Producers: Imported organic matter supports beach food webs. ​ Consumers: ​ Suspension feeders: Sand crabs, clams (feed on plankton). ​ Wrack feeders: Amphipods, isopods, kelp flies (feed on seaweed). ​ Deposit feeders: Worms (consume detrital particles). ​ Carnivores: Shorebirds, crabs, fishes, sea mammals. Ecosystem Functions and Services ​ Habitat Provision: Supports specialized intertidal species. ​ Natural Filtration: Traps pollutants in sand as water percolates. ​ Coastal Protection: Dissipates wave energy, reducing erosion. ​ Recreation: Beaches drive tourism and cultural activities. ​ Nursery Grounds: Critical for species like grunions. Coastal Dunes ​ Formation: ​ Sand blown inland from beaches forms dunes, stabilized by vegetation. ​ Examples: Guadalupe Dunes. ​ Ecological Role: ​ Endemic plant species (e.g., yellow sand verbena) adapted to low nitrogen and herbivory. ​ Threatened by invasive species like ice plant.  ​ Human Impacts: ​ Dune stabilization, restoration efforts to protect native habitats. Chaparral and Coastal Sage Scrub Ecosystems Coastal Sage Scrub (CSS) ​ Definition: A shrub-dominated plant community primarily found on coastal slopes of Southern California, with some areas extending 100 km inland. ​ Characteristics: ​ Drought-deciduous: Plants drop leaves during dry periods to conserve water. ​ Often referred to as “soft chaparral” due to its low-growing, less woody shrubs. ​ Seasonal growth: Flourishes in spring with flowers, dormant in summer. ​ Adapted to coastal fog, which provides additional moisture. ​ Flora: ​ California sagebrush and other sages. ​ Fauna: ​ California gnatcatcher: Threatened species reliant on CSS habitat. ​ Coast horned lizard: Found in CSS, chaparral, and grasslands. ​ Ecosystem Services: ​ Erosion control: Stabilizes slopes, especially after rain. ​ Water regulation: Reduces runoff and supports groundwater recharge. ​ Biodiversity support: Provides critical habitat for plants and animals. ​ Natural beauty: Aesthetic and cultural value. ​ Threats: ​ Urban development: Over 25% of CSS converted to urban areas, with only 10-15% intact. ​ Invasive species: Grass invasion creates a feedback loop with fire, disrupting native scrub. Chaparral ​ Definition: A dense, woody shrub ecosystem found in Mediterranean climates (wet winters, dry summers), typically at higher elevations and farther inland than CSS. ​ Characteristics:  ​ Dominated by evergreen sclerophyllous shrubs with thick, leathery leaves to reduce water loss. ​ Found on rocky, low-nutrient soils. ​ Fire-adapted, with long fire return intervals (30–150+ years). ​ Flora: ​ Manzanita ​ Ceanothus: Nitrogen-fixing shrubs with fire-stimulated germination. ​ Chamise ​ Tiny, drought-resistant leaves. ​ Resprouts from burls after fire. ​ Indicator plant for fire danger due to oil-rich leaves. ​ Knobcone pines: Serotinous cones that open only after fire. ​ Fauna: ​ Habitat for diverse species, including mammals, birds, and insects. ​ Fire Adaptations: ​ Resprouting: Plants like chamise regenerate from root crowns post-fire. ​ Fire-stimulated germination: Seeds of plants like Ceanothus require heat or smoke to germinate. ​ Flammable leaves: Promote natural fire cycles. ​ Ecosystem Services: ​ Biodiversity support: Critical habitat for fire-adapted and drought-tolerant species. ​ Erosion control: Stabilizes steep slopes. ​ Cultural and recreational value: Popular for hiking and landscaping plants. ​ Threats: ​ Increased fire frequency: Human activities disrupt natural fire intervals, reducing species diversity. ​ Urban encroachment: Habitat loss and fragmentation. ​ Invasive species: Grass invasions alter fire dynamics and outcompete native plants. Key Differences Between CSS and Chaparral ​ Dominant Plants: ​ CSS: Drought-deciduous shrubs (e.g., sagebrush). ​ Chaparral: Evergreen shrubs (e.g., chamise, manzanita). ​ Leaf Adaptation: ​ CSS: Soft-stemmed, seasonal leaf drop. ​ Chaparral: Thick, leathery leaves conserve water. ​ Fire Regime:  ​ CSS: Shaped by grazing and low-intensity fires. ​ Chaparral: Adapted to high-intensity fires. ​ Soil Nutrients: ​ CSS: Higher nitrogen due to coastal fog. ​ Chaparral: Low-nutrient, rocky soils. ​ Location: ​ CSS: Coastal slopes, lower elevations. ​ Chaparral: Higher elevations, farther inland. Conservation Notes ​ Protecting these ecosystems is vital for their biodiversity, ecosystem services, and cultural significance. Restoring disturbed areas and managing fire regimes are critical steps to preserving chaparral and coastal sage scrub ecosystems. Coast Redwood Forests Overview of Coast Redwoods (Sequoia sempervirens) ​ Range: Found along the Pacific coast, from Northern California to southern Oregon. ​ Habitat: Prefers cool, moist conditions with frequent fog and wet winters. ​ Distribution: Grows in a narrow strip, 20-30 miles wide, along the coast. ​ Longevity: Lives 1,000–2,000 years. ​ Stature: Among the tallest trees in the world, capable of creating their own microclimate. Comparison of Coast Redwoods and Giant Sequoias ​ Coast Redwoods: ​ Found at lower elevations along the coast. ​ Frequent fog provides moisture during dry summers. ​ Giant Sequoias (Sequoiadendron giganteum): ​ Found in Sierra Nevada groves at 5,000–7,000 feet elevation. ​ Longevity of up to 3,000 years; thrives in snowy winters and dry summers. Adaptations for Longevity  1.​ Pest and Disease Resistance: ​ Tannins in bark and wood deter insects and fungi. ​ Symbiotic fungal microbes in leaves combat pathogens. ​ Highly resistant to decay. 2.​ Disturbance Adaptations: ​ Thick bark protects against fire and pests. ​ Can sprout from the base after damage. ​ Flood tolerance: Can regenerate roots after silt burial. 3.​ Water Acquisition: ​ Fog drip supplements water needs during dry months. ​ Needle absorption of fog moisture through stomata. ​ Shallow but wide root systems anchor massive trees and access broad water sources. 4.​ Light Access in Crowded Forests: ​ Towering height captures light in dense forests. ​ Efficient photosynthesis even in low-light conditions. Reproduction ​ Sexual Regeneration: ​ Old-growth redwoods produce millions of seeds annually, but only 10% are viable. ​ Seeds germinate on bare soil cleared by fire or flooding. ​ Vulnerable to herbivory by species like banana slugs. ​ Asexual Regeneration: ​ Sprouting from burls: New trees grow as clones of the parent, forming fairy rings. ​ Burls enable recovery after damage. Fire and Redwood Forests ​ Fire is less frequent in northern, wetter stands (125–500 years) compared to southern areas (~50 years). ​ Older trees are protected by thick bark, but repeated fires can hollow trunks, forming goose pens. ​ Fire clears forest floors, aiding seed germination and growth. Ecological Role ​ Canopy Diversity: Harbors many species, particularly invertebrates. ​ Pollination: Primarily by flies and moths. ​ Other Plants: Coexists with species like: ​ Douglas fir  ​ Tanoak ​ California bay laurel ​ Redwood sorrel (adapted to low light). Unique Canopy life: Redwood forest first thought to be ‘zoological desert’ until life in the canopy was discovered: soil, other plants including trees, salamanders etc. ​ Animal Species: ​ Pacific banana slug ​ Clouded salamander History and Conservation 1.​ Exploitation: ​ Heavy logging for timber began during the Gold Rush, supplying early San Francisco. ​ Only 4-5% of old-growth redwood forests remain. ​ Logged areas left stump-filled landscapes. 2.​ Conservation Movement: ​ 1902: Big Basin State Redwood Park established by the Sempervirens Fund. ​ 1918: Formation of Save the Redwoods League. ​ 1968: Creation of Redwood National Park after decades of advocacy. 3.​ Modern Advocacy: ​ Activists like Julia Butterfly Hill lived in a redwood tree (“Luna”) for over two years to protest logging. Unique Features ​ Albino Redwoods: ​ Genetic mutations result in white needles due to a lack of chlorophyll. ​ Act as parasites on parent trees, relying on their root systems for nutrients. Ecosystem Services ​ Climate Regulation: Store large amounts of carbon. ​ Water Regulation: Reduce runoff and support groundwater recharge. ​ Erosion Control: Stabilize soils on slopes. ​ Biodiversity: Provide habitat for diverse plants and animals. ​ Cultural Value: Significant to conservation history and indigenous cultures. Coast redwoods stand as a testament to resilience, adaptation, and the importance of conservation efforts in the face of exploitation and climate change. Montane Forests California’s Montane Forests: Key Attributes ​ Global Importance: Among the most productive and diverse temperate ecosystems. ​ Record-Breaking Trees: Home to the world’s largest single-stem tree, the General Sherman Giant Sequoia. ​ Biodiversity Hotspot: Contains the highest conifer diversity in the world (30+ species in the Klamath-Siskiyou range). ​ Ecosystem Characteristics: Distinct due to high productivity, seasonal drought, and fire dependence. ​ Distribution Influences: ​ Strongly shaped by temperature and precipitation gradients. ​ Elevation and proximity to the Pacific Ocean play critical roles. Major Forest Types 1.​ Sierran Mixed Conifer Forest 2.​ Klamath Mixed Conifer Forest 3.​ White Fir Forest 4.​ Montane Hardwood-Conifer Forest 5.​ Giant Sequoia Groves 6.​ Eastside Pine Forest Key Tree Species 1.​ White Fir: Shade-tolerant and thrives in well-drained soils. 2.​ Red Fir: Prefers higher elevations; valued for timber. 3.​ Incense Cedar: Known for fragrant, scale-like leaves; used in pencil production. 4.​ Jeffrey Pine: Distinguished by its vanilla- or butterscotch-scented bark. 5.​ Ponderosa Pine: Recognizable by its jigsaw puzzle-patterned bark. 6.​ Sugar Pine: Produces the longest cones of any pine species. 7.​ Douglas-fir: Not a true fir; unique cones with 3-pronged bracts. 8.​ California Black Oak: Vital for wildlife; acorns were a staple for Native Americans. 9.​ Giant Sequoia: Among the oldest living organisms, with thick bark and exceptional fire resistance. Ecosystem Dynamics Fire’s Role  ​ Ecological Benefits: 1.​ Creates diverse tree groupings and open spaces, supporting wildlife. 2.​ Clears underbrush, reduces competition, and adds nutrients to the soil. 3.​ Promotes healthy forests by maintaining a balance of tree sizes and species. ​ Fire Suppression Issues: ​ Forests become too dense, reducing habitat diversity and increasing vulnerability to pests and drought. Water’s Role ​ Water availability affects plant growth, nutrient cycling, and resilience during droughts. ​ Coastal fog and precipitation gradients play significant roles in montane forest health. Threats to Montane Forests 1.​ Drought and Beetles: ​ Prolonged droughts lead to increased competition for water, especially in dense forests. ​ Stressed trees are more vulnerable to bark beetles, which have killed millions of trees, including Ponderosa pines. 2.​ Zombie Forests: ​ Climate change mismatches tree species to local conditions. ​ After major disturbances, mature forests may transition to shrubby, drought-adapted vegetation. Montane Forest Fauna ​ Species Diversity: Home to 355+ vertebrate species. ​ Sensitive Species: ​ California Spotted Owl: Needs old-growth trees and high canopy cover. ​ Black-Backed Woodpecker: Relies on dead trees from fires. ​ Fisher and Northern Flying Squirrel: Depend on large trees and unique habitat features. ​ Impacts of Fire Suppression: ​ Loss of shrub patches for songbirds. ​ Reduced availability of tree cavities for birds and mammals. Key Concepts for Reflection 1.​ Fire and Water: How do these elements shape the structure and diversity of montane forests?  2.​ Forest Management: How can fire regimes and reduced forest density benefit sensitive species? 3.​ Climate Adaptation: What does the future hold for “zombie forests”? Subalpine and Alpine Ecosystems Subalpine Ecosystem ​ Definition: The transition zone below the alpine zone where trees can still grow, though conditions are harsh. ​ Key Features: ​ Elevation: Highest forested elevations in California, just below the treeline. ​ Forest Characteristics: Sparse, open woodlands; influenced by snow, wind, extreme temperatures, and a short growing season. ​ Climate Influence: Non-living factors dominate, including harsh winters and a brief summer growing period. Alpine Ecosystem ​ Definition: The zone above the treeline where the climate is too harsh for trees to grow, resembling tundra-like conditions. ​ Key Features: ​ Elevation: Found between 9,000 and 13,000 feet. ​ Climate: Cold temperatures, strong winds, high UV radiation, and a very short growing season. ​ Soil: Thin, rocky, with low water retention. ​ Vegetation: Hardy, low-growing plants like dwarf shrubs, perennial grasses, and wildflowers. ​ Glaciers: Remnants of the Little Ice Age (1450–1920 CE) are present in alpine zones. Treeline ​ Definition: The elevation at which trees can no longer grow due to extreme environmental conditions. ​ Significance: ​ Reflects changes in climate and ecosystems. ​ Warming climates may cause treelines to shift upward, altering the landscape and impacting plant and animal habitats. Key Tree Species in Subalpine Zone 1.​ Whitebark Pine:  ​ Symbiotic relationship with Clark’s Nutcracker. ​ Adapted to harsh conditions with features like high seed production and strip-bark growth. 2.​ Bristlecone Pine: ​ The oldest living individual trees on Earth. 3.​ Foxtail Pine: ​ Found near treeline, adapted to cold and wind exposure. Alpine Ecosystem Vegetation ​ Dominated by: ​ Fell Fields: Areas dominated by rocks with sparse vegetation. ​ Hardy plants like dwarf shrubs, perennial grasses, and wildflowers. Animals of Subalpine and Alpine Zones 1.​ Sierra Nevada Bighorn Sheep (Ovis canadensis sierrae): ​ Endangered species native to the Sierra Nevada. ​ Conservation efforts have increased populations from ~100 in the 1990s to several hundred today. 2.​ American Pika (Ochotona princeps): ​ A small mammal adapted to rocky alpine environments. Adaptations in Subalpine and Alpine Zones ​ Tree Adaptations: ​ Krumholtz Growth: Stunted, wind-blown trees near the treeline. ​ Long needle retention and resilient growth forms for harsh conditions. ​ Plant Adaptations: ​ Tolerant of thin, rocky soils and extreme weather. ​ Low-growing forms to withstand wind and UV radiation. ​ Animal Adaptations: ​ Species like bighorn sheep and pika are adapted to cold, low oxygen, and limited food availability. Reflection and Discussion 1.​ Treeline Movement: How does climate change affect treeline elevation and ecosystem dynamics? 2.​ Biodiversity and Conservation: What efforts are needed to protect sensitive species like the Sierra Nevada bighorn sheep? 3.​ Adaptation to Extremes: How do plants and animals thrive in such harsh environments? Desert Ecosystems California’s Desert Ecosystems Overview Deserts, defined as regions receiving less than 10 inches (25 cm) of annual precipitation, cover approximately 38% of California’s land area. ​ Key Deserts: 1.​ Great Basin Desert: ​ The only cold desert in the U.S. ​ Precipitation primarily in the form of snow. ​ Features pine and juniper woodlands. 2.​ Mojave Desert: ​ Occupies 30% of California. ​ Known for endemic plants and Death Valley (lowest point in North America). 3.​ Colorado Desert: ​ Part of the larger Sonoran Desert. ​ Features the Salton Sea and Lake Cahuilla remnants. ​ Dominated by creosote bushes and paloverde trees. Factors Influencing Desert Ecosystems ​ Abiotic Factors (most important due to extreme conditions): ​ Climate: High temperatures, low and variable precipitation. ​ Soils: Often sandy or rocky with low nutrients. ​ Geology: Parent material affects nutrient content and plant communities. ​ Geomorphic Settings: 1.​ Playas (dry lake beds): Seasonal water supports invertebrates and migratory birds. 2.​ Eolian Sand Dunes: Formed by wind, habitat for species like the Mojave fringe-toed lizard. 3.​ Alluvial Fans: Accumulations of rock and sand from floods; support slightly more vegetation due to better soil and water availability. Adaptations to Desert Life Plant Strategies 1.​ Escape: Annual plants remain dormant as seeds until conditions are favorable. ​ Example: Annual wildflowers during superblooms.  2.​ Evade: Cacti and succulents store water in specialized tissues. ​ Example: Silver cholla. 3.​ Endure: Plants with deep roots, waxy coatings, or drought-deciduous leaves. ​ Example: Creosote Bush: ​ Deep roots and waxy leaves. ​ Allelopathy: Releases chemicals to inhibit nearby plant growth. Animal Strategies ​ Behavioral and physiological adaptations: ​ Desert Tortoise: Spends 99% of time underground, collects rainwater to drink. ​ Gila Monster: Highly underground lifestyle; stores water in its body. ​ Desert Kit Fox: Large ears dissipate heat. ​ Desert Pupfish: ​ Extremophiles, thriving in high temperatures and low oxygen environments. ​ Example: Devil’s Hole Pupfish, found only in a single limestone cave pool. Biological Soil Crusts (Biocrusts) ​ Communities of microorganisms, mosses, and lichens. ​ Benefits: ​ Stabilize soil. ​ Add nutrients through nitrogen fixation. ​ Help retain moisture. Human Use and Impacts 1.​ Human Impacts: ​ Mining, agriculture, and urban expansion degrade ecosystems. ​ Renewable energy projects alter desert habitats. 2.​ Conservation Efforts: ​ Protected areas like Joshua Tree and Death Valley National Parks. ​ The California Desert Protection Act safeguards large desert areas. 3.​ Challenges: ​ Balancing development with conservation. ​ Adapting to climate change and managing scarce water resources. Key Desert Plants ​ Joshua Tree: Iconic species of the Mojave Desert. ​ Creosote Bush: Longevity and drought adaptations. ​ California Fan Palm: ​ Found in oases along the San Andreas fault. ​ Provides habitat for animals and is fire-resistant.