Lesson 25 - Why Biodiversity Matters

25: why biodiversity matters Wednesday, March 27, 2024 1:07 PM the intrinsic value of biodiversity • the natural world is inherently important ○ inspires art, poetry, music, dance, etc. ○ tied to spirituality ○ enjoyed and appreciated in many ways • value in itself and its existence • can be enough of an argument to protect biodiversity for some but not for others the ecological value of biodiversity • biodiversity is correlated with ecosystem function ○ primary production, nutrient cycling • diversity is directly proportional to biomass produced • diversity at lower trophic levels support diversity at higher trophic levels ○ more plants = more herbivores = more predators the economic value of biodiversity • ecosystem services: functions provided by nature that support humans ○ products extracted from ecosystems (paper) ○ processes that maintain healthy ecosystems (water filtration) ○ culture benefits from ecosystems the economic value of biodiversity • ecosystem services: functions provided by nature that support humans ○ products extracted from ecosystems (paper) ○ processes that maintain healthy ecosystems (water filtration) ○ culture benefits from ecosystems • done for free without any cost to us; readily provided • estimating the monetary value of ecosystem services can be easy or difficult ○ easy: value of lumber harvested from a forest ○ difficult: aesthetic value of a forest • value of ecosystem services often only recognized when they are lost ○ when possessions/resources with a price are lost because of the absence of an ecosystem service, then their value is realized • ecosystem services were said to be $33 trillion (twice the global gross income), then $125 trillion which of the following are ecosystem services? I) taxol, a chemotherapy drug from yew trees, II) a hiking trail in shenandoah national park, III) an oyster reef that filters water in the chesapeake bay a. I & II b. I & III c. II & III d. I, II, & III threats to biodiversity a. b. c. d. I & II I & III II & III I, II, & III threats to biodiversity factors that make a species vulnerable • unsuccessful reproduction • narrow range of resources ○ geographic or dietary • less competitive ability • limited genetic diversity ○ limited opportunity to adapt ○ less variation that allows others in the species survive • small population size ○ a catastrophic event can wipe out the entire species factors that prevent species extinction • • • • • successful reproduction greater range more competitive ability greater genetic diversity larger population size habitat loss • humans have modified up to 75% of the earth • greater genetic diversity • larger population size habitat loss • humans have modified up to 75% of the earth • nearly all biomes have experienced some habitat loss • what types of activities lead to habitat loss? invasive species • species with high abundance that affect other organisms and the ecosystem as a whole • impact on native ecosystems: ○ reduced biological diversity ○ changes in species interactions ○ changes in ecosystem services overexploitation • harvesting past the point where a population can recover ○ particularly problematic for long-lived species • affects all levels of diversity ○ bottleneck effect ○ trophic cascade ○ changes ecosystem processes global change • an increase in atmospheric CO2 has led to a mean global temperature increase of 1 ºC • widespread impacts on biodiversity ○ habitats become unsuitable ○ resources reduced ○ timing of biological events altered ○ loss of species interactions