Ecological Restoration BIO 409 Dr Mc Ewan Endangered

Ecological Restoration (BIO 409) Dr. Mc. Ewan Endangered Species

An opening meditation on the ecology of rarity

Why are some species rare and others abundant? Short’s goldenrod, endangered Kentucky

Why are some species rare and others abundant? 1) Population biology Some species become rare because they do not have the reproductive capacity to succeed in the face of changes in habitat conditions. Some species are “naturally” uncommon. This can be exacerbated when a species with relatively low reproductive rates finding themselves living in a world in which the habitat is turning over far more rapidly in than at any point in their evolutionary history.

Why are some species rare and others abundant? One expression of this idea is the “Slow plants in a fast forest” idea from plant population biologist Glenn Matlack. He used modeling to show that many forest floor herbaceous species lack the reproduction and dispersal capacity to adapt to life in a landscape where habitat patches are rapidly turning over. Trillium is a good example of this idea. This species may take 10 years to reach reproductive maturity. It does not produce fruit every year. The disperser agent(s) are poorly understood. It is assumed that for many Trillium, dispersal is just a few feet a year, at most. This species cannot withstand forest harvesting and cannot easily disperse into habitats from where it has been eliminated.

Why are some species rare and others abundant? General trends in the reproductive biology of rare plants. -Very often they produce few fruits, that have very minimal dispersal distances. -Are self-incompatible. -Have specific pollinator relationships that create vulnerability. (lose the pollinator, no more reproduction) -Are commonly pollen limited because there are not enough individuals around. -Seed set is uncommon and weak. -Some years, no seeds at all.

Why are some species rare and others abundant? General trends in the reproductive biology of rare animals. -Not as clear general trends. -Mostly “K-selected species” -Bats for instance, have one or two babies a year max.

Why are some species rare and others abundant? Human Ignorance and Avarice The most important reason most species are rare is the simple fact that humans killed them. Or destroyed there habitat. Most often the reasons humans have for driving animals to extinction, or near extinction, can be attributed to stupidity, blood lust, or greed. Example, at the last turn of the century, bison were so frequent they were uncountable. In the millions. Humans then killed them- for no reason at all- in such great numbers that they were on the verge of extinction.

Why are some species rare and others abundant? Human Ignorance and Avarice The US Army sanctioned and actively endorsed the wholesale slaughter of bison herds. [25] The US Federal government promoted bison hunting for various reasons, to allow ranchers to range their cattle without competition from other bovines, and primarily to weaken the North American Indian population by removing their main food source and to pressure them onto the reservations. [26] Without the bison, native people of the plains were forced either to leave the land or starve to death. 10 s of millions to a few hundred in a just a few decades

Black Rhino: ~70, 000 individuals in 1960 <3000 in 2004 Why? They are killed for there horns which are used for ceremonial dagger handles and Chinese medicine- it is used to make a potion that increases male sexual stamina.

Many examples… If an animal is valuable- it is going to be killed… very difficult to stop.

Why are some species rare and others abundant? Fear In North America in particular we have a long tradition of killing carnivores. We do this because we are afraid. Sometimes we argue that they will kill our sheep or something, but mostly it is just because we don’t like the idea of something comin’ round that might kill us. http: //www. youtube. com/watch? v=Ugz 1 O 01 Nf 0 k&feature=fvw

By far the most important contributor to species extinction and rarity is the loss of habitat due to industrialization.

“Industry” includes farms AND suburbs

In response to a biodiversity crisis, the US Government passed a law protecting endangered species. The goal of the law is to prevent species from going extinct. It is quite a remarkable law. Very few nations have such a law. Canada for instance, has nothing of the sort. The Endangered Species Act of 1973: PURPOSES. —The purposes of this Act are to provide a means whereby the ecosystems upon which endangered species and threatened species depend may be conserved, to provide a program for the conservation of such endangered species and threatened species… Endangered Species Act http: //www. epa. gov/lawsregs/laws/esa. html Actual Text http: //epw. senate. gov/esa 73. pdf

The Endangered Species Act, in practice focuses on: 1) Preserving habitat 2) Preventing exploitation of animals (via hunting etc. ) 3) Requires restoration These are often extremely controversial Spotted Owl: Endangered

Preserving habitat One cannot destroy habitat that is known to be home to a federally endangered species. This means if an endangered species is found on YOUR property, nothing can be done on that property that would destroy the habitat. If you are a logger, you probably hate this law. These are often extremely controversial Red-cockaded woodpecker: Endangered

Preserving habitat Caves or old oaks or hickory trees on your property? If an Indiana bat is found on your premises -that property will be locked down by ESA for the foreseeable future… These are often extremely controversial Indiana Bat: Endangered

Preventing exploitation of animals (via hunting etc. ) It is illegal to kill, or even possess an Endangered Species. If this dude has a hold of your newborn colt on a horsefarm in Florida- you can do absolutely nothing harmful to the cougar. These are often extremely controversial Florida Panther: Endangered

Requires restoration For each Endangered Species the US govt is required to develop a recovery plan. That plan will explain specific goals for the species and its habitat that must be pursued in order to create a viable enough population of the organism that it can be delisted. These plans would be extremely expensive and difficult to enact. However, every species MUST have one. Ecological restoration plans are outlined in the recovery plan. Ivory Billed Woodpecker: Extinct?

Requires restoration Restoration could involve habitat creation, or modification. It could involve transportation and “reintroduction” of species- or both. It could involve control of a predator. Little-winged Pearly Mussel Endangered

Population Viability Analysis. -Attempt to model population conditions through time, to predict the success or failure of a population. -Models assume a range of conditions, and the predict success based on those assumptions. -Modeler can alter the assumptions/alter the conditions to examine the influence of particular environmental or demographic features on population success. -Most folks recognize that modeling populations in this way is fraught with difficulty because SO much is unknown about SO many species. In fact, many species for which ecological restoration is needed are relatively unknown! -In application, population modeling IS effective for identifying risks. Maybe most importantly it is used for finding “weak links” in the demographic processes of a given species.

Population Viability Analysis, Cont. - It is also useful for helping guide initial restoration, particular with choosing which life phase to install (seedings vs. seeds), and for identifying threats to restoration success. -PVA includes estimates of “uncertainty: ” variation arising from random environmental and demographic events. -Elasticity- is a measure of population growth relative to variation in life-stage transition probabilities. For instance, the probability of transition from one life phase to the next can be manipulated. Populations can also be modeled with population numbers distributed unevenly among life-stages. Population growth is modeled. -In some instance, long-term demographic instability can be identified based on life-stage distributions.

Questions: 1) How many individuals to introduce? 2) How large do the patches have to be? 3) What developmental stage to be used? 4) What counts for suitable habitat 5) Dispersal and Colonization 6) Spatial Arrangement of Habitats 7) Sources? Sinks?

Requires restoration, which requires long-term commitment, and engenders…complications…