Chapter 11: Restoring Populations and Species

Ecological restoration

assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed

reference state

the specific set of criteria or goals we have for the outcome of the restoration

shifting baselines

occurs when human perceptions of what is "normal" for an ecosystem change across generations

Reference states are often chosen based on two factors.

history

ecology (particularly community and ecosystem functioning)

Rewilding

the idea of restoring ecological processes using native species, such as wolves, cougars, or beavers, or surrogate species that are no longer on the landscape but who served important ecological roles in the past, such as the American cheetah, the mastodon, and North American camelids.

In-situ preservation

on-site

best strategy for conservation

3 options for maintaining, preserving, and restoring populations

establishing new populations (a form of in-situ)

ex-situ (off site) preservation

hybrid model of both

ex-situ preservation

occurs under artificial conditions under direct human supervision

long-term goal is the eventual release of the species into the wild and establishment of new populations

hybrid strategy between in-situ and ex-situ

the monitoring and management of populations of species in small protected areas

ex.) Elk and Bison Prairie at LBL

Reintroduction

releasing captive-bred or wild-caught individuals into an ecologically suitable site within their historic range where the species no longer occurs

releasing individuals into an existing population to increase its size and/or gene pool

augmentation

introduction

moving animals or plants to areas suitable for the species outside of their historic range

last resort

3 strategies for establishing new populations

reintroduction

augmentation

Introduction

behavior of released animals

finding, catching, and manipulating prey

socializing with other members of the same species

recognition and avoidance of predators and humans

… is by far the most inexpensive and successful conservation option.

Protection of species and habitat in the wild is by far the most inexpensive and successful conservation option.

How do we know when to use ex-situ methods? Here are three questions we need to ask.

How necessary and effective are these methods for a specific species?

If the species cannot be eventually reintroduced into the wild, is it worth saving anyway?

Are species held ex-situ for their own benefit or for that of the institution?

Cross-fostering

a technique where foster parents raise young

Ex.) Sandhill cranes have been used to foster whooping crane chicks, and by taking eggs from whooping crane nests, the pair will produce another clutch of eggs, doubling the potential reproductive output of one pair of whooping cranes.  

Plants are much easier to maintain ex-situ than animals because

1. we can establish populations using seeds, cuttings, and rhizomes

2. plants can be grown at high densities with adequate resources

3. many plants can be grown outdoors with little care

4. pollination is often free via wind or animals

5. seeds can often be stored in a dormant state for many years

seed bank priority should be given to plant species that are

1. threatened

2. unique

3. can be reintroduced

4. can be preserved ex-situ

5. have potential economic value

The number of seeds collected per individual should be based on seed viability; if viability is low, ______ are collected.

more

Plants with low reproduction should be collected….

over a series of years in smaller quantities to minimize negative effects on wild populations

Because so much diversity has been lost, we cannot just conserve, but also must:

restore

The specific set of goals for the outcome of a restoration effort is called its ______ state.

reference

Shifting baselines are when human perceptions of ecosystems change across:

time and generations

Reference states are chosen using _______ and _______

history and ecology

Pleistocene rewilding is a type of restoration focused more on ________ than _________.

ecology, history

True or false. Restoration efforts are, by definition, ex-situ.

false

Land Between the Lakes' Elk and Bison Prairie is an excellent example of a ______ restoration strategy.

hybrid

In-situ and ex-situ strategies are:

complementary

Three of the benefits of establishing new populations are

1. increasing the number and size of populations

2. spreading species among several different populations

3. allowing a species to regain its ecological role

Releasing individuals into an existing population to increase its size is called:

augmentation

Successful restoration programs often include:

good genetic background

True or false. Public support is one of the most important traits of a successful restoration.

True

3 limitations of ex-situ conservation include:

1. population size

2. genetic variation

3. continued funding

Pandas are an excellent example of the focus that many zoological parks place on:

charismatic megafauna

One commonly used strategy to increase reproduction in zoos is

cross-fostering

Three current problems with existing plant conservation include:

1. seed storage

2. genetic variation

3. focus on plants used for food