Ecology Ch.2 Keystone Species and the Longleaf Pine Ecosystem

one species that is a small part of an ecosystem can affect the community and ecosystem as a whole greatly- removal causes drastic changes to the ecosystem and even its eventual collapse

Keystone Species Concept

pollinators- functions they provide

apex predators- top-down population control

species with connections to many other species

species with unique services that are performed by few or no other species

4 major keystone species types

Robert Paine’s removed sea stars from an area and mussel population exploded- mussels out-competed other species for space/ resources but were held in check by sea star predation- causing a decrease in other species’ numbers from 20 to 1 in 10 years

Keystone species hypothesis

soils that flooded seasonally, drier flatlands, Sandhills

sub-tropical to temperate conifer forest

where are longleaf pine ecosystems found

2% left because of the value of longleaf pine timber, fire suppression, Rosin, tar, pitch, and turpentine

Longleaf pine ecosystems decline

clearing brush allowing for herbaceous understory

cycle nutrients

burning wiregrass cleanses forest floor

role of fire in Longleaf Pine Ecosystem

forest wouldn’t burn properly- other species would block sunlight - Herbaceous plants decline in number

debris build up- devastating forest fires

Wiregrass as a keystone species

large burrows=

apron of nutrient rich soil when digging

shelter from heat and fires for over 300 species

numbers decrease because of loss of longleaf pine ecosystem

Gopher Tortoise

primary cavity nesters- build nests in live trees (fire and predator protection)- roughly 30 species use abandoned nests

Red-Cockaded woodpecker as keystone species

massive decline since European settlement of America

caused by loss of longleaf pine forests

family units- 4 male helpers, 3-5 eggs per year

60-70% mortality rate

Red-Cockaded woodpeckers

apex predator- massive decline

decrease caused increase in herbivores→ certain plant species decline→ increase in erosion

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elk declined, increase in plant species, increase in trees= decreased water temperature= better for trout, increase in beavers and dams, decrease in coyotes, increase in smaller mammals

Gray Wolves decline and re-introduction in Yellowstone

Ranchers- prey upon their cattle and sheep

Hunters- compete for big game

Loggers and miners- lose access to wolf populated land

What groups weren’t happy with the re-introduction of Gray wolves and why?