Land Use History and Patterns of

Biodiversity in Southern

Appalachian Forests

Scott M. Pearson

Mars Hill College & Coweeta LTER

Southern Appalachia / Southern Blue Ridge Province

Grayson

Madison

Buncombe

Macon

Environmental Variation

Gradients in local abiotic conditions

(moisture, temperature, light, nutrients) as

influenced by elevation, topographic

position, latitude , and edaphic factors.

Landscape change and land-use history.

Topography

influences

distribution of

community types

in

Southern

Appalachians.

Mt. LeConte,

Great Smoky Mountains

Spruce-Fir (boreal

coniferous)

Heath Bald

Northern Hardwoods

Xeric Oak-pine

Mixed Hardwood

Cove Forest

Climatic gradients

affect the local

distribution of

community types.

Robert Whittaker (1956)

related community types

to elevation and landform

in Great Smoky

Mountains.

Temperature decreases

and precipitation

increases with increasing

elevation.

Local landform

modulates moisture

abundance.

Snowball Mountain in Craggy Mtns, Buncombe Co., NC

Topography

influences

distribution of

community

types in

Southern

Appalachians.

Biological diversity & Landscape change

Natural variation in temperature, moisture,

and fertility creates a mosaic of abiotic

conditions that favor high species diversity.

Human-induced variation:

Socioeconomic driven changes in forest cover

over time influenced by terrain, transportation,

and location of market centers.

Land uses: late 1800s-early 1900s• Extensive farming for subsistence and market.

Lan

d u

ses:

ear

ly 1

90

0s

• Logging with mules - Sodom, Madison Co., NC

• and oxen -Big Ivy, Buncombe Co., NC

Land uses: 2006

Landscape change in

Madison County, NC

1950-1990.

Landscape change

in the vicinity of

Mars Hill NC

1950-1990

What are the patterns of landscape

change occurred in the 20th century?

Beginning in mid-1900s, agriculture declined and

there was an expansion of forest via secondary

succession.

In the mid- to late-1900s, there was an expansion

of residential/suburban/urban development with

decline in forest cover around populated areas.

In the late 1900s to present, there is an increase in

the number of buildings (homes) in the forest.

M. G. Turner, S. M. Pearson, P. Bolstad and D. N. Wear. 2003. Effects of land-cover change on

spatial pattern of forest communities in the Southern Appalachian Mountains (USA). Landscape

Ecology 18: 449–464.

Heterogeneous history of today’s forests

Post-agriculture (1900 farms - 2000 forest)

Post-logging (logged twice in 20th century)

Reference (least disturbed, not logged in past 75 yrs)

Categories of land-use history for field studies

Example research questions:

Do these categories of sites vary with respect to the

diversity and abundance of selected plant and animal

species? (salamanders, birds, arthropods, understory herbaceous plants)

Past Land use and

Salamander Diversity

Salamanders and invertebrates sampled at 12 sites in

Craggy Mountains.

Four sites per land use category.

49 pitfall traps (7 x 7 grid,

10 m spacing) per site.

Traps open one week/month over 12 months.

Salamanders - working hypotheses:

Salamander diversity and

abundance are greatest at least

disturbed sites.

Salamander diversity and abundances

are more similar for post-logging

and least disturbed sites.

Post-agricultural sites would be

more different from the other land

use categories.

Land use and Salamander Abundance

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00m

ea

n c

ap

ture

s +

/-S

E least distrbd post-logging post-agric

Land use category

Salamander HabitatsDifferences salamander abundances may be explained in part by differences in habitat characteristics among land-use categories.

Salamander abundances were positively correlated with…

Basal area of shade-tolerant, mesophytic tree species,

Abundance of coarse woody debris, and

Depth and coverage of leaf litter.

These habitat qualities were most available in the least disturbed stands.

N. G. Hicks and S. M. Pearson. 2003. Salamander diversity and abundance in forests with alternative

land use histories in the Southern Blue Ridge Mountains. Forest Ecol. Manage. 177:117-130.

Past Land use

and

Herbaceous

Plants

Species Groups based on

Taxonomy & Habitat

Liliaceae: Disporum spp., Uvularia grandiflora, Trillium erectum

Generalists: Sangunaria canadensis, Arisaema triphyllum, Polystichum acrostichoides, Tiarella cordifolia

Weedy spp.: Pilea pumila, Ranunculus spp.

Old growth spp: Viola canadensis, Osmorhiza claytonii, Hepatica acutiloba, Stellaria pubera

Mesophytes: Laportea canadensis, Impatiens spp., Cryptotenia canadensis

Effects of land-use history on wildflower groups

0

5

10

15

20

25

30

Pe

rc

en

t C

ov

era

ge

Lilly Weedy Old-growth Mesophyte

Species Group

least dist

logged

post-ag

Land-use

Species richness and composition were similar among reference and

post-logged sites, but abundances differed.

Weedy & exotic species present in post-ag sites and near forest edges.

Polygonatum biflorum

Sanguinaria canadensis

Disporum lanuginosum

Select focal herbaceous species included in this study. Others included Arisaema

triphyllum, Aster divaricatus, Astilbe biternata, Cimicifuga racemosa, Goodyera pubescens, Orchis

spectabilis, Osmorhiza sp., and Prenanthes altissima.

Land use, soils & wildflowers

How does prior land use affect the spatial distribution of soil nutrients?

Do understory plants respond to spatial structure in soil nutrients?

(Fratterigo et. al. 2005. Effects of past land use on spatial heterogeneity of soil nutrients in Southern Appalachian forests. Ecol. Monogr.

75:215-230.)

Spatial variability in soilsIncreasing intensity of prior land use increases variability between sites but reduces variability within/among plots.

Hypothesized mechanisms:Soil disturbance by agricultural or forestry practices.

Change in ecosystem function-- i.e., litter/organic inputs.

Nitrogen (g/kg)

Between-site Within-site Within-plot

0.0

0.4

0.8

1.2

1.6

Carbon (g/kg)

Between-site Within-site Within-plot

Vari

ance

0

20

40

60

80

Calcium (mg/kg)

Between-site Within-site Within-plot

0

10

20

30

40

50

Grazed Logged Reference

Spatial structure in plant abundance

Logged

0 5 10 15 20

0.0

0.4

0.8

1.2

1.6

2.0

Reference

0 5 10 15 20

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0.4

0.8

1.2

1.6

2.0

Distance (m)

0 5 10 15 20

0.0

0.4

0.8

1.2

1.6

2.0

Distance (m)

0 5 10 15 20

Sem

ivariance

0.0

0.4

0.8

1.2

1.6

2.0

ReferenceLogged

Figure 3. Standardized semivariograms showing differences in the spatial structure of herbaceous species in

formerly logged and undisturbed sites, and before (top two panels) and after (bottom two panels) variability

due to soil nutrient availability was removed. Three plots indicated by different colored dots are shown in

each panel.

Land use & fragmentation

Research question: Do land use history and

forest fragmentation interact to influence

biological diversity of herbaceous species?

Does forest

fragmentation and

the spatial pattern

of landscape

change influence

these

communities?

Species richness and abundance are greater in large (>200 ha) than small patches (<25 ha), and several native

mesic forest herbs are less abundant or absent in forest patches that experienced intensive past land use

(Pearson et al. 1998. Forest fragmentation, land use, and cove-forest herbs in the French Broad River Basin.

Castanea 63:382-394 ).

Forest patch size & herb diversity

0

1

2

3

4

5

6

7 P

er

ce

nt

C

ov

er

ag

e

Lilly Weedy Old-growth MesophyteSpecies Group

Large Small

Herbs Spp. and Patch SizeHigh Dis turbance -Transects 1996

Patch Size

Does forest

fragmentation and

the spatial pattern

of landscape

change influence

these

communities?

Surrounding landscape affects local plant community

4

6

8

10

12

14

16

He

rb

Sp

ec

ies

Ric

hn

es

s

50 60 70 80 90 100

Pre-1950 forest in landscape (%)

Landscape ContextDiversity in post-1950 stands

Land use & fragmentation

Research question: Do land use history and

forest fragmentation interact to influence

biological diversity of herbaceous species?

Hypotheses regarding fragmentation:

Small patches have inferior habitat.

Fragmentation interferes with dispersal.

Dispersal Limited Species

Many forest-interior wildflowers have no adaptations for long-range dispersal of seeds.

Many species, such as Trillium spp. and Uvularia spp., are dispersed by ants. Dispersal distances due to ants seldom exceed 10 m.

Limited dispersal means that these species are slow to colonize new habitat and their populations may decline from the effects of habitat fragmentation.

Species Common name Species Common name

Anemone quinquefolia Windflower Uvularia

grandiflora

Large-flowered bellwort

Asarum canadense Wild ginger Uvularia perfoliata Perfoliate bellwort

Carex spp. Sedges Uvularia pudica Mountain bellwort

Disporum lanuginosum Yellow mandarin Uvularia

sessilifolia

Sessile bellwort

Disporum maculatum Speckled mandarin Viola blanda Sweet white violet

Hepatica acuta Sharp-lobed liver leaf Viola canadensis Canada violet

Hepatica americana Round-lobed liver leaf Viola hastata Halberd-leaved violet

Erythronium americanum Trout lily Viola pubescens Hairy violet

Sanguinaria canadensis Blood root Viola rotundifolia Round-leaved yellow violet

Tiarella cordifolia Foam flower Viola sororia Common blue violet

Trillium grandiflorum Large-flowered trillium

Trillium erectum Wakerobin

Myrmecochores = ant-dispersed plants

Seeds of most species include a lipid-rich body (eliasome).

The purpose of this study was to

examine a potential mechanism that

might explain the reduced abundance and diversity of

myrmecochores (ant-dispersed plant species) in small forest

patches with high intensities of past land use.

The primary research questions were:

•Do ant species richness and ant abundance vary among mesic

forest patches that differ in size and intensity of prior land use?

•Are myrmecochores most abundant and diverse in locations

where ants are also most abundant and diverse?

Forest fragmentation &

ant diversity

Mitchell, C., M. G. Turner, and S. M. Pearson. 2002. Effects of historical land use and forest patch size on myrmecochores and ant

communities. Ecological Applications 12:1364-1377.

0

2

4

6

8

10

12

14

16

18

General Adult Juvenile Seedling

Me

an

# o

f M

yrm

ec

oc

ho

re S

pe

cie

s

Pe

r S

ite

+ 2

SE

Age Class

Myrmecochore Richness

small-high

large-high

large-low

a

aaa

a b a a b

a a

a bb

a

Myrmecochore richness

0

1

2

3

4

5

6

7

Small / High Large / High Large / Low

Mean

An

t S

pecie

s R

ich

nes

s P

er

Sit

e +

2S

E

Patch Size / Land Use Intensity

Ant Species Richness

a ba,b

Ant abundance/diversity was negatively correlated with patch

size and positively correlated with past land use intensity.

Ant diversity, land use, patch size

0

2

4

6

8

10

12

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18

20

0 2 4 6 8

Myrm

eco

ch

ore

Ric

hn

ess

(# m

yrm

eco

ch

ore

s / s

ite)

Ant Richness (# species / site)

Myrmecochore Richness vs. Ant Richness

Large/High

Large/Low

Small/HighLarge-high

Myrmecochore vs ant richness

Aphaenogaster spp. = seed dispersers; Camponotus spp.= seed predators

Mean # colonies sampled

per site

Patch size-land use

treatment

Species name

Total # of

colonies

sampled

N = 9

Small-

high

N = 10

Large-

high

N = 5

Large-

low

Aphaenogaster fulva 376 10.1 a

19.0 b

19.0 b

Aphaenogaster rudis 75 7.9 a

0.4 b

0.0 b

Camponotus pennsylvanica 38 3.8 a

0.2 b

0.4 a,b

Camponotus chromaiodes 29 2.1 a

0.9 a

0.2 a

Lasius alienus 12 0.6 0.7 0.0

Formica schaufussi 9 0.4 0.5 0.0

Lasius umbratus 3 0.3 0.0 0.0

Crematogaster cerasi 2 0.2 0.0 0.0

Crematogaster vermiculata 2 0.2 0.0 0.0

Myrmecina americana 2 0.2 0.0 0.0

Prenolepis imparis 2 0.0 0.2 0.0

Camponotus castaneus 1 0.1 0.0 0.0

Paratrechina melanderi 1 0.1 0.0 0.0

Total # Collections 552

Ant species

SummaryDifferences in topography and land use history create spatial heterogeneity in biodiversity of our region.

The importance of this land use legacy varies among taxonomic groups.

Ecosystem dynamics, such as succession, drive changes in habitat suitability over time.

Spatial patterns can interact with life history characteristics, such as dispersal ability, to affect community composition in dynamic landscapes.

These landscapes are resilient and can recover from human disturbances but the legacy of past uses persists for decades.