Schueller NRE 509 Lecture 19: Landscape Ecology Applied – 1. Fragmentation 2. The Design of Reserves and Landscapes What allowed your metapopulation to persist (not crash) even when populations went extinct?

High enough: ______

Not too high:______Landscape Ecology APPLIED: 1. Fragmentation a. What is it/what does it look like? b. What causes it? c. What are the consequences?

Previously continuous habitat is fragmented into patches within a matrix Causes of fragmentation?

•Natural - fires, floods, succession •Anthropogenic -

NOTICE Variation in patch & matrix type, and: • Area • Shape • Arrangement (connectivity) Residential development, Northern Forest (VT, MA) Clear-cut logging, Pacific Northwest Highway, Banff National Park, Canada Agriculture Seismic Survey lines for gas/oil exploration Tar sands oil extraction Alberta, Canada Causes of fragmentation? •Natural - fires, floods, succession,… •Anthropogenic

- agriculture, logging, development, oil & gas extraction, mining,…

- fences, roads, powerlines, dams, …

What are the consequences? The world’s ongoing fragmentation experiments

Haddad et al. 2015. Habitat fragmentation and its lasting impact on Earth’s ecosystems. Sci Adv. 1:e1500052 • Largest and longest-running experiment to study fragmentation in tropical forests • Manaus, Brazil • Started in 1979 • By logging, set up a series of forest patches, ranging in size from 1 to 100 ha http://pdbff.inpa.gov.br/iarea.html General findings: Ecological • Increased mortality of mechanisms? tree species • Loss of frugivorous Use your smarts to birds in small fragments • Loss of large predators come up with specific in small fragments hypotheses •Increase in generalist species What are the implications of fragmentation? 1. AREA effects (fragment size)

Species-area relationship

Competition = smaller populations = increased chance of extinction

+ excludes species with large home range How large is enough? What does it depend on?

For example, - Trophic level • Butterflies that move less - Dispersion of than128 m in their lifetime resources in • Mice with home ranges of the habitat about half a hectare. • Jaguars with home ranges of at least 10 km2 (4 mi2) But why do fragments have even fewer species than controls - the same area within a forest?

Laurance, et al. 2002. Ecosystem Decay of Amazonian Forest Fragments: a 22-Year Investigation. Conservation Biology 16 (3): 605–618. What are the implications of fragmentation? 2. EDGE effects Physical: altered microclimate

Biological: - Increased predation - Competition with EDGE edge species What are the implications of fragmentation? 3. lack of DISPERSAL between fragments What are the implications of fragmentation? Generally: Loss of species that were there before

Why? 1. 2. 3. Landscape Ecology Applied – 1. Fragmentation 2. The Design of Reserves and Landscapes

Can island biogeography and metapopulation theory help manage fragmented landscapes?

p = 1 – e_ c Which is a “better” reserve design for diversity? A or B Why? Size

Number

Proximity

Arrangement

Connectivity

Shape Reserve design What if they’re not close? Acquire land to connect: create corridors Are corridors effective? Corridors

Tewksbury, Haddad, and others Connected patches had higher movement of animals, pollen, and seeds

“Corridors work as a superhighway for plants and animals and they use them a lot” - Haddad

Tewksbury, et al.2002. Corridors affect plants, animals, and their interactions in fragmented landscapes. Proceedings of the National Academy of Sciences 99:12923-12926. Haddad, et al. 2003. Corridor use by diverse taxa. Ecology 84 (3): 609–615. • Will corridors still be effective when climate shifts? • Is just connecting enough to offset habitat loss? • Is managed relocation the future of conservation? Single Large Or Several Small? Reserve design: How many? The SLOSS debate Single large or several different small

Depends on: • Habitat heterogeneity (Beta diversity) • Minimum viable population size • Dispersal among small • Quality of the Matrix “Early findings drew our attention to the effects of creating an abrupt edge between forest and adjacent pasture. Over time, most of the cattle pastures that originally isolated our reserves were abandoned and let revert to second-growth forest. …we discovered .. the landscape around forest reserves...can be more important than the size of the reserve in determining what species will be found in an isolated patch of forest.” E.g. different types of agriculture = effect dispersal and edge effects of tropical forest fragments

Species richness of ground-foraging ants in forest fragment >> conventional farm with little shade = organic farm with shade

Perfecto & Vandermeer . 2002. Quality of Agroecological Matrix in a Tropical Montane Landscape: Ants in Coffee Plantations in Southern Mexico. Conservation Biology 16(1): 174-182 “As the theory states and empirical work confirms, regional extinctions will occur if there is no interfragment migration to balance the inevitable local extinctions. A focus on the matrix, through which these migrations must occur, is thus required if we are serious about solving the extinction crisis …and that matrix is usually an agroecosystem of some sort.” 2007. Conservation Biology Volume 21, No. 1, 274–277 The Matrix Matters! The Matrix is… How would you improve the quality of the matrix? What kind of 0.5 acre suburban backyard or 50 acre agricultural field would: • Increase connectivity (allow for re- colonization events and reduce inbreeding depression) among patches? • Minimize loss of interior/high quality habitat area and reduce edge effects? • Provide a stop-over site or corridor for migratory animals? Recommended reading At a cocktail party or from a bathroom stall could you talk eloquently about:

• spatial scale • Fragmentation • Immigration • Corridors • Emigration • edge effect • Migration • filter effect • Colonization • Metapopulations • Dispersal • source-sink dynamics • landscape mosaic • island biogeography • species-area relationship • Metacommunity • The matrix (not the movie) • SLOSS debate • connectivity