remains largely unstudied. Plant ecological investigations often have been been have often investigations ecological Plant unstudied. largely remains

1985, Gerrish 1990), the quantitative ecology of tropical Pacific island forests forests island Pacific tropical of ecology quantitative the 1990), Gerrish 1985,

Micronesica Micronesica

Saipan, MP 96950. 96950. MP Saipan,

' '

With the exception of the Hawaiian Islands (summaries in Mueller-Dombois Mueller-Dombois in (summaries Islands of Hawaiian the exception the With

alien species. species. alien

ingly native, suggesting that native forest is resistant to invasion by by invasion to resistant is forest native that suggesting native, ingly dominate under conditions of low forest disturbance. Despite centuries centuries Despite disturbance. low of forest conditions under dominate

fhmnrltd irpin frs cmoiin ean overwhelm­ remains composition forest disruption, human-related of

eefeun i bt te aoy n udrtr, a cm t pre­ to come may understory, and canopy the both in frequent were

lings. Commonly fruiting, shade tolerant species species like tolerant shade fruiting, lings. Commonly

posed in which which in posed

understory may be maintained in the forest through disturbance, which which disturbance, through forest the in maintained be may understory

were the major understory species. A model of forest dynamics is pro­ is dynamics forest of model species. A understory major the were

might facilitate vegetative propagation, flowering, or survival of seed­ of survival or flowering, propagation, vegetative facilitate might

were the principal canopy species, and and species, canopy principal the were

alence, the importance value, showed that that showed value, importance the alence,

highest densities in the understory. The relative measure of forest prev­ of forest measure relative The understory. the in densities highest

densely in the canopy, and and canopy, the in densely

whereas whereas

nae nae

the canopy and and canopy the

each, I found that mean canopy and understory basal area were, re­ were, area basal understory and canopy mean that found I each,

770. 770. spectively, 45140 45140 spectively,

point-quarter sampling technique on 400 canopy and understory trees trees understory and canopy 400 on technique sampling point-quarter

importance, tree basal area, and tree density in that habitat. Using the the Using habitat. that in density tree and area, basal tree importance,

pan, was studied to characterize the species composition, relative species species relative species the to was characterize pan, composition, studied

Abstract-A Abstract-A

Present Present

Ecological Characteristics of a Native Limestone Forest on on Forest Limestone Native a of Characteristics Ecological

dominated in the understory. understory. the in dominated

Pisonia grandis grandis Pisonia

25(1): 8S-97, 1992 1992 25(1): 8S-97,

address-. address-.

Cynometra ramif[ora, Pouteria obovata, obovata, Pouteria ramif[ora, Cynometra

remnant native limestone forest in the Marpi region, Sai­ region, Marpi the in forest limestone native remnant

Northern Marianas College, Box 1250, Commonwealth No. Mariana Islands, Islands, Mariana No. 1250, Commonwealth Box College, Marianas Northern

understory understory

P. grandis grandis P.

± ±

overwhelmingly dominated in canopy basal area, area, basal canopy in dominated overwhelmingly

24144 and 1460 1460 and 24144

Commonwealth No. Mariana Islands, Islands, Mariana No. Commonwealth

Saipan, Mariana Islands Islands Mariana Saipan,

Division of Fish and Wildlife, Wildlife, and Fish of Division

ROBERT ROBERT

were, were,

and other species largely absent from the the from absent largely species other and

Saipan, MP 96950 96950 MP Saipan,

C. C.

Introduction Introduction

ramif[ora ramif[ora

respectively, 794 794 respectively,

Cynometra ramif[ora ramif[ora Cynometra

J. J.

CRAIG

± ±

C. C.

749 m 749

ramif[ora ramif[ora

and G. G. and

P. grandis grandis P.

1 1

2

/ha. Mean trees/ha in in trees/ha Mean /ha.

and and

mariannae mariannae

C. C.

± ±

and G. G. and

and and

uma marian­ Guamia

ramif[ora, ramif[ora,

174 and 2579 2579 174 and

occurred most most occurred

C. C.

mariannae mariannae

ramif[ora ramif[ora

had the the had

which which

± ± de-

& &

(Sus (Sus

(Fosberg (Fosberg

Rinehart Rinehart

& &

L.) L.)

Cervus unicolor) unicolor) Cervus

m apart. The first transect transect apart. The m first

(Engbring et et (Engbring al. to 1986)

5% 5%

250 250

(Saccharum officinarum officinarum (Saccharum

savanna, savanna, mangrove swamp, freshwater swamp,

Micronesica Micronesica ), 25() 1992

(Fosberg (Fosberg 1960, Wiles et al. the 1989), present ap­

Study Study Area and Methods

Casuarina-Pandanus Casuarina-Pandanus

were present present were ca. 1960.

1980). In addition, Fosberg ( 1960) gave descriptions descriptions gave of the principal In 1960) addition, plant 1980). ( Fosberg

(Pteropus mariannus) mariannus) (Pteropus

To To obtain data the on composition structure the Marpi and forest, of species

The The Marpi region of Saipan has the most extensive and among the best

Because the Because native forests of Saipan have been subjected to centuries of

Native Native forest on Saipan is estimated to cover

To begin providing providing begin comprehensive To quantitative data on Mariana Island for­

5, 5,

mid- to lower elevations, where forest was usually best developed. High elevation elevation High developed. best usually mid-was forest where elevations, to lower

1960), which largely isolated isolated which the largely Marpi 1960), forest from other tracts of native forest.

the the last near its southern end. Transects were parallel to the slope contours at

as Suicide Cliff. Others Others placed south were the escarpment's along Cliff. as Suicide and slope west I established 10 transects with starting points points about starting with transects established 10 I

was was located near the northern comer of the steep limestone escarpment known

which which have been introduced to Saipan, but local residents report that pigs

scrofa) scrofa) There There are no feral ungulates in this area, bar even Deer Sam (

level level areas were cultivated for sugarcane

developed developed native forest remaining on Saipan. However, before World War II,

( 1991) has has been followed. 1991) (

alterations. alterations. In this study, the taxonomic nomenclature of Raulerson

pearance of Saipan's limestone forest likely reflects the combined effects of these of these the combined Saipan's pearance of effects reflects limestone forest likely

19% (Young (Young of 1989) 19% the island. Most surviving native forest occurs on steep factors. Hence, the following analysis must be considered in light of anthropogenic anthropogenic of light in considered must be analysis following the Hence, factors.

Bats Bats

war-related war-related damage, and virtual extirpation of seed-dispersing Marianas Fruit

human-related alteration, including cutting, burning, browsing by feral ungulates, ungulates, feral by human-related alteration, browsing cutting, burning, including and and strand forest are present also (Fosberg 1960).

on on limestone-derived soil), although examples of ravine forest on growing vol­

canic canic soil, limestone escarpments and may be classified as limestone forest (forest that that grows (forest forest limestone as classified be and may escarpments limestone

Furthermore, Furthermore, qualitative comparisons of this study area were made with other

tracts tracts of limestone forest to the assess of generality my findings.

197 197

the forest, inferences were made made the were concerning inferences forest, future trends in composition. forest

habitat. habitat. From comparative data on the canopy and understory components of

ests, ests, I studied the native limestone forests of Saipan. I characterized the species

composition, composition, importance, relative species area, tree and basal tree density in this

acterized acterized native forest found along transects single on Guam.

associations of Micronesia, Micronesia, and associations of and Moore Muniappan (1973) each char­ (1976)

have have concerned plant systematics and Stone (e.g. floristics Fosberg et 1970, al.

equator. equator. Most botanical studies that include the Mariana Islands, Micronesia,

Steadman Steadman (in press) provided quantitative data on Pacific islands south of the

Woodroffe Woodroffe 1985, although 1987), Ash (1987), Merlin (1991), and Franklin

scriptive scriptive accounts of distributions and plant associations (e.g. Maxwell 1982, 86 86

individuals to 242 cm dbh present. present. dbh cm 242 to individuals

in basal area (Table 1). It was the largest species in the forest, with massive massive with forest, the in species largest the was It 1). (Table area basal in

canopy trees/ha: trees/ha: canopy

but understory trees had the greatest density (canopy basal area (m area basal (canopy density greatest the had trees understory but

770, CV CV 770,

CV) similar in the canopy and understory. Canopy trees dominated in basal area area basal in dominated trees Canopy understory. and canopy the in similar CV)

transects, with the relative variance (as measured by the coefficient of variation, variation, coefficient of the by measured (as variance relative the with transects,

forest, basal area (Figure (Figure area basal forest,

= =

canopy or understory, thereby providing insights into shifting patterns of forest forest of patterns shifting into insights providing thereby understory, or canopy

species composition. composition. species

portance value ratio highlights those species which predominate in either the the either in predominate which species those highlights ratio value portance

t a ersne i te nesoy te lsr t vle a o - to was value its closer the understory, the in represented was it

those predominating in the understory. The more strongly a species was repre­ was species a strongly more The understory. the in predominating those

sented in the canopy, the closer its ratio was was to its ratio closer the canopy, the in sented

to species predominating in the canopy, and negative values were assigned to to assigned were values negative and canopy, the in predominating species to

nesoy a optd ydvdn te mle au b h lre,ad sub­ and larger, the by value smaller the dividing by computed was understory

tracting the quotient from from quotient the tracting

because they are distinct, absolute measures of overall tree occurrence. occurrence. tree overall of measures absolute distinct, are they because

& &

related to proportionate contribution of of a species (Holmes forest to foliage volume contribution proportionate to related

Dombois Dombois

ne fr ah pce nw a te motne au (eiwd y Mueller­ by (reviewed value importance the as known species each for index

forest (frequency). From these 3 measures, I computed a relative importance importance relative a computed I measures, 3 these From (frequency). forest

stems (basal area), no. stems/unit area (density), and dispersion of trees in the the in trees of dispersion and (density), area stems/unit no. area), (basal stems proved the most equitable measure of diameter. diameter. of measure equitable most the proved

For the variety of tree growth forms encountered in the limestone forest, dbh dbh forest, limestone the in encountered forms growth tree of variety the For the canopy but taller than than taller but canopy the

sample point to the center of the tree and the diameter at breast height (dbh). (dbh). height breast at diameter the and tree the of center the to point sample as those first intercepting sunlight, and understory trees were those growing growing were those below trees understory and sunlight, first intercepting as those

used to measure measure to used

Kagman, as well as on Guam, Rota, and Tinian. Tinian. and Rota, Guam, on as well as Kagman,

points). For comparison, limestone forests were studied qualitatively elsewhere elsewhere qualitatively studied were forests limestone comparison, For points).

on Saipan, particularly at Tapotchau, Gualo Rai, Naftan, Dandan, Talufofo, and and Talufofo, Dandan, Naftan, Rai, Gualo Tapotchau, at particularly Saipan, on

was sufficient to make each point independent (i.e. no overlap in trees between between trees in overlap no (i.e. independent point each make to sufficient was

forest on steep slopes was often characterized by stunted, exposed forest. On each each On forest. exposed stunted, by characterized was often slopes steep on forest

transect, I placed 10 sample points paced about 12 m apart (108 m total), which which total), m (108 apart 12 m about paced points 10 sample placed I transect,

45140 45140

Robinson 1981). Tree density and basal area were also examined separately, separately, examined also were area basal and density 1981). Tree Robinson

Pisonia Pisonia grandis

The The

For each species, a ratio of importance values in the canopy versus the the versus canopy the in values importance of ratio a species, each For

Point-quarter analysis yields data on the horizontal area covered by tree tree by covered area horizontal the on data yields analysis Point-quarter

The plotless point-quarter sampling technique (Cottam and Curtis 1956) 1956) was Curtis and (Cottam technique sampling point-quarter plotless The

= =

2 2

± ±

& &

absolute measures of overall tree occurrence in the Marpi limestone limestone Marpi the in occurrence tree overall of measures absolute

30). 30).

24144, CV= 53, understory basal area: area: basal understory 53, CV= 24144,

Ellenberg 1974). For broad-leaved forests, the importance value is is value importance the forests, broad-leaved For 1974). Ellenberg

x x

4 4

canopy and and canopy

= 794 794 =

R. Br. showed overwhelming canopy dominance among trees trees among dominance canopy Br. R. showed overwhelming

1) 1)

± ±

1. 1.

2 2

Craig: Ecology of Limestone Forest Forest Limestone of Ecology Craig:

and density (Figure (Figure density and

Results and Discussion Discussion and Results

m. For each tree, I measured the distance from the the from distance the measured I tree, each For m.

For graphical clarity, positive values were assigned assigned were values positive clarity, graphical For

174, CV = 22, understory trees/ha: trees/ha: understory 22, = CV 174,

4 4

understory trees/point. Canopy trees trees were Canopy defined trees/point. understory

In In

contrast, the abundant but slender-trunked slender-trunked but abundant the contrast,

1 1

and, similarly, the more strongly strongly more the similarly, and,

2), 2),

varied substantially between between substantially varied

= =

1460 1460

± ±

749, CV = 51; 51; = CV 749,

2

x x

/ha: /ha:

= 2579 2579 =

1. 1.

x x

h im­ The

± ±

SD SD

± ± 87 87

C. C.

(Saff.) (Saff.)

(R.Br.) (R.Br.)

ramif[ora ramif[ora

was was com­

C. C.

P. P. grandis

h h

Pouteria obovata obovata Pouteria

The irregularly distributed The distributed irregularly

Guamia Guamia mariannae

g g

. .

understory understory

trees trees that suggested its distribution

-

e e

transect transect

bijuga bijuga

(Colebr.) 0. (Colebr.) Kuntze occurred commonly at

C C

canopy canopy

Micronesica 25(1), 1992 1992 25(1), Micronesica

were were the ), principal and canopy (Table species 1

were the major understory species (Table 2). Because Because 2). the major (Table were understory species

(j). (j).

had had the highest density, whereas

and and the Marianas endemic

D D

Intsia Intsia bijuga

L. had had L. basal area relatively low

(Gaud.) (Gaud.) dominated W.L. Chew at only one transect. In the

even even more strongly predominated in density than they had

ramiflora ramiflora

a a

C. C.

ramif[ora ramif[ora

G. mariannae mariannae G.

C. C.

was was not abundant, its importance value a was reflection largely of its

and and

north north (a) to south

and and

mariannae mariannae

. .

Figure Figure I. area Basal of canopy and understory trees at transects arranged IO from

4000 4000

The relative measure of forest prevalence, the importance the importance forest that prevalence, relative The of showed measure value,

8000 8000

G

Canopy Canopy tree densities exhibited a divergent pattern from basal areas (Table

12000 12000

16000 16000

Cynometra Cynometra ramif[ora

20000.------~ 20000.------~

ramiflora ramiflora

P. grandis grandis P.

P. grandis grandis P.

. . ) 1

in in basal area (Table 2).

Marpi forest which appeared In appeared which the Marpi to forest understory, have been logged.

and and

was was at least in part an artifact of It logging. was the only native species in the

the the southernmost 5 transects, but was virtually absent in the northern portion

~ ~ ns ns

of of the study area. Stumps /. of logged paratively paratively uncommon.

ns ns

~ ~ E E

Baehni Baehni also had a high average basal area (Table 2).

Merr. predominated, predominated, Merr. distributed although the irregularly

understory, understory, Cynometra Cynometra ramiflora

Dendrocnide Dendrocnide latifo/ia

~ ~

"iii "iii .0 .0

-

.c .c ro ro

"'--- 88 88

between the basal area of canopy and understory understory and canopy of area basal the between

basal area in the understory (canopy: (canopy: understory the in area basal

area (although not significantly; canopy: canopy: significantly; not (although area

286.4 286.4

understory trees showed little relationship to each other other each to relationship little trees showed understory

end of the study area (Figure 4). However, the basal areas of the canopy and and canopy the of areas basal the However, 4). (Figure area study the of end C. C.

area from north to south, but its basal area declined sharply near the southern southern the near sharply declined area basal its but south, to north from area

provided by World War II shrapnel embedded in their trunks, indicating an age age an indicating trunks, their in embedded shrapnel II War World by provided (sometimes appearing to be broken branches that had rooted) were observed, but but observed, were rooted) had that branches broken be to appearing (sometimes

understory understory basal area (Figure 3). Canopy heterogeneity in basal area (Figure 1) 1) largely mir­ (Figure area basal in heterogeneity Canopy 3). (Figure area basal infrequently. A minimum age for some of the larger larger the of some for age minimum A infrequently.

± ± rored its uneven basal area distribution. In contrast to its canopy dominance, no no dominance, canopy its to contrast In distribution. area basal uneven its rored

>47 yr, and possibly > 100 100 yr. > possibly and yr, >47

l l

CU CU

ramiflora, ramiflora,

101.3 101.3 m

1000 1000

2000 2000

3000 3000

4000 4000

5000~------~ 5000~------~

In both the canopy and understory, understory, and canopy the both In

± ±

Figure 2. Density of canopy and understory trees at 10 transects arranged from from arranged transects 10 at trees understory and canopy of Density 2. Figure

243.1 m 243.1

2

P. P. grandis

north (a) to south south to (a) north

/ha; /ha;

which averaged highest in canopy compared to understory basal basal understory to compared canopy in highest averaged which

t t

2

a a

/ha; /ha;

= =

5.3, df df 5.3,

were encountered on transect points. Saplings and seedlings seedlings Saplings and points. transect on were encountered

t t

b b

D D

= =

(j). (j).

1.0, 1.0, df

Craig: Ecology of Limestone Forest Forest Limestone of Ecology Craig:

= =

C C

canopy canopy

8, P P 8,

= =

d d

< <

8, P > 0.3), 0.3), > P 8,

x x

0.001). Again, little relationship existed existed relationship little Again, 0.001).

C. C.

transect transect

= =

e e

x x

-

ramiflora ramiflora

20.0 20.0

= =

464.4 464.4

f f

understory understory

± ±

G. mariannae G. mariannae (r

G. G. mariannae

23.7; understory: understory: 23.7;

g g

showed an increase in basal basal in increase showed an

± ±

P. P. grandis

(r

509.5; understory: understory: 509.5;

2 2

= =

h h

0.5, 0.5, df

had its highest highest its had

specimens was was specimens

2 2

= =

= =

x x

8). 8). Unlike

0.4, df df 0.4,

= =

175.9 175.9

x x

= =

= = 89 89

1 1

5 5

.

.

9 9

6 6

.

.

1.7 1.7

2.0 2.0

3.2 3.2

4.9 4.9 5.1 5.1

5.0 5.0

4.6 4.6

10.5 10.5

5.4 5.4

9.2 9.2

17.5 17.5

4.0 4.0

6 9.5 9.5

9

6.2 6.2 7.1 7.1

25.5 25.5

40

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

1 1

2 2

0 0

.

.

.

1.5 1.5 ± 4.6

1.6 1.6

1.5 1.5

1.6 1.6

1.9 1.9

0.6 0.6

0.6 0.6 ± 1.9

0.7 0.7

2

2.3 2.3

5 7.4 7.4

6.3 6.3

7.3 7.3 ± 8.4 4.6 4.6 ± 13.8

8.0 8.0

8.5 8.5

9

9.0 9.0 ± 11.4

9.5 9.5

14.2 14.2 ± 12.9

16.6 16.6 ± 29 11.9 11.9

15.6 15.6

57.4 57.4 ± 28.6

21.4 21.4

73.5 73.5

Importance Importance value

were were detected only in

1 1

5 5

6 6

5 5

2 2

.

. .

.

.

. 1 1

.

.

12.1 12.1

18

19

6.1 6.1

6.1 6.1

6.1 6.1

14.2 14.2

35.1 35.1

110.0 110.0

22.5 22.5

39.9 39.9

64.0 64.0

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

8 8

7 7

bijuga, bijuga,

7 7 ± 18.5

3 3 ± 54

9 9 ± 22

9 9

9 9 ± 32.7

5 5 ± 33 8 8 7 ± 31.

3 3

0 0 ± 31.1

2 2 ± 82.0

.

.

.

.

.

.

.

.

.

.

. .

1.9 1.9 ± 6.1

1.9 1.9

1.9 1.9 ± 6

1.9 1.9

1.9 1.9

5.8 5.8 ± 13.0 3

7

5.8 5.8 ± 13.0

7

Trees/ha Trees/ha

17

17.3 17.3

17.3±24.7 17.3±24.7

24

24

26

23

26.9 26.9

36 28

21.1 21.1

32.6 32.6

65 40

44.1 44.1 ± 41.5

65.2 65.2 ± 45.4

214.9 214.9

and and /.

7 7

4 4

9 9 .

6 6 .

3 3 .

.

. .

2 2

.

104.2 104.2

192

7

131.8 131.8

2.5 2.5

28.4 28.4

100

6.4 6.4

66.1 66.1

46.0 46.0

396.9 396.9

23.7 23.7

365

230.1 230.1

982

4901.4 4901.4

which appears to flower and and fruit regularly, appears to flower which

± ±

± ±

± ±

± ± /ha) /ha)

± ± 22.1

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

2

3 3

.

(m

1.7 1.7 ± 5.1

0.8 0.8

2.4 2.4

8.8 8.8

3.1 3.1

P. P. grandis

Basal area area Basal

13

12.6 12.6 ± 26.3

53.0 53.0 ± 158

34.7 34.7

66.7 66.7 ± 200.1

78.7 78.7

64.2 64.2

37.6±41.1 37.6±41.1 25.1 25.1 ± 38.1

88.6 88.6 ± 88.1

49.3 49.3

40.5 40.5

20.0 20.0

91.0 91.0

163.2 163.2 ± 158.9

153.0 153.0 ± 171.5

179.7 179.7

274.6 274.6

509.2 509.2

302.1 302.1

464.4 464.4 ± 509.5

Micronesica 25( 1 ), ), 1992 1 25( Micronesica

5747.4 5747.4

flowers only only flowers rarely (although it heavily in flowered

order order by importance values.

SD) SD) of canopy trees in the Marpi forest, arranged in descending

D. latifolia, D. latifolia,

± ±

(Mm) (Mm)

also also appears to infrequently flower on Saipan, although

(No) (No)

(Am) (Am)

(Om) (Om)

(LI) (LI)

(Dd) (Dd)

(Ai) (Ai)

(Ag) (Ag)

(Cr) (Cr)

(DI) (DI)

bijuga bijuga

(Gm) (Gm) (Ps) (Ps)

(Ev) (Ev)

(Pt) (Pt)

(Pr) (Pr)

(Cs) (Cs)

(Mc) (Mc)

(Pd) (Pd)

(Aa) (Aa)

(Po) (Po)

Pisonia Pisonia grandis

(Pg)" (Pg)"

(Ac) (Ac)

(Al) (Al)

(Cp) (Cp)

(Ft) (Ft)

(Fp) (Fp)

(lb) (lb)

leucocepha/a leucocepha/a

The The ratio of importance values for canopy and understory trees (Figure 6)

Table Table 1. Mean occurrence (

so so may also profit from disturbance or other unusual circumstances.

suggests that that suggests this and other regularly fruiting canopy species with importance

rarity in the understory the in rarity understory of

value value ratios approaching may 1 have that seeds germinate poorly in shade, and

Furthermore, Furthermore, /.

in in the understory may indicate that reproduction occurs primarily after distur­

some fruits and seedlings were found found were during the study. fruits The and rarity species these some seedlings of

bance, bance, such as after typhoons, or after some other unusual circumstance. The

Feb.-Mar. 1991), and propagates vegetatively from broken branches (Stone (Stone broken 1970). branches from vegetatively and propagates Feb.-Mar. 1991),

the the canopy.

showed that showed 2 common species,

8), 8), and the distribution of basal areas in the study area showed no consistent

pattern pattern (Figure 5).

Cordia subcordata subcordata Cordia

• • Abbreviations of names species in parentheses are used in Figure 6

Drypetes do/ichocarpa do/ichocarpa Drypetes

Pandanus tectorius tectorius Pandanus Aidia cochinchinensis cochinchinensis Aidia

Pandanus dubius dubius Pandanus Acacia confusa confusa Acacia

Ochrosia mariannensis mariannensis Ochrosia Marinda citrifo/ia citrifo/ia Marinda Artocarpus mariannensis mariannensis Artocarpus

Psychotria mariana mariana Psychotria Artocarpus a/ti/is a/ti/is Artocarpus

Neisosperma oppositifo/ia oppositifo/ia Neisosperma

Guamia mariannae mariannae Guamia Carica papaya papaya Carica Leucaena Leucaena

Pouteria obovata obovata Pouteria Albizia /ebbeck /ebbeck Albizia

Erythrina variegata variegata Erythrina

Ficus pro/ixa pro/ixa Ficus

Ficus tinctoria tinctoria Ficus Aglaia mariannaensis mariannaensis Aglaia

Cynometra ramiflora ramiflora Cynometra Premna obtusifo/ia obtusifo/ia Premna

Melanolepsis multiglandulosa multiglandulosa Melanolepsis

I ntsia bijuga bijuga ntsia I

Dendrocnide /atifolia /atifolia Dendrocnide

Pisonia grandis grandis Pisonia

Species Species 90 90

Aidia cochinchinesis cochinchinesis Aidia

(Stone 1970, Raulerson and Rinehart 1991 1991 Rinehart ) and 1970, Raulerson (Stone

(Merr.) Fosb. are small trees that rarely grow large enough to invade the canopy canopy the invade to enough large grow rarely that trees small are Fosb. (Merr.)

dance during periods of low forest disturbance. disturbance. forest low of periods during dance

rdc rcutet no h udrtr. uhseislkl nraei abun­ in increase likely species Such understory. the into recruitment produce

though these suffer high mortality in the dry season, clearly enough survive to to survive enough clearly season, dry the in mortality suffer high these though

opnns fte oet ebcos ae n h wt esn(ueNv) Al­ (June-Nov.). season wet the in layer herbaceous forest the of components

approaching or <0. In fact, seedling seedling fact, In <0. or approaching Ficus tinctoria tinctoria Ficus

reproduced readily in shade as demonstrated by their importance value ratios ratios value importance their by demonstrated as shade in readily reproduced

tatively propagate, however. however. propagate, tatively

rnhs rm oh pce otd srue lae,ad lwrddrn Oct.­ during flowered and leaves, sprouted rooted, species both from branches

some other mechanism, such as fruiting after a period of unusual weather. weather. unusual of period a after fruiting as such mechanism, other some

Nov. Other native tree species, including/. including/. species, tree native Other Nov.

Marpi was littered with numerous branches of of branches numerous with littered was Marpi

• Abbreviations of species names in parentheses are used in Figure 6. 6. Figure in used are parentheses in names species of Abbreviations • species was obtained after a September, 1991 typhoon, when the forest floor at at floor forest the when typhoon, 1991 September, a after obtained was species

Leucaena Leucaena leucocephala

Albizia /ebbeck /ebbeck Albizia Melanolepsis Melanolepsis multiglandu/osa Dendrocnide Dendrocnide latifolia

Erythrina variegata variegata Erythrina Pandanus Pandanus tectorius

Ficus Ficus pro/ixia

Maytenus thompsonii thompsonii Maytenus Neisosperma Neisosperma oppositifolia

Premna obtusifolia Premna obtusifolia

Aglaia mariannensis Aglaia mariannensis Marinda Marinda citrifolia Psychotria Psychotria mariana

Ficus Ficus tinctoria

Aidia cochinchinensis cochinchinensis Aidia Eugenia Eugenia pa/umbis Carica Carica papaya

Pandanus Pandanus dubius

Pouteria Pouteria obovata

Ochrosia Ochrosia mariannensis

Species Species Cynometra Cynometra ramiflora

Guamia mariannae mariannae Guamia

Table 2 Table

Of those species predominating in the understory (Figure 6) (Figure understory the in species predominating those Of

In contrast to these species, heavily fruiting, common canopy species like like species canopy common fruiting, heavily species, these to contrast In

Support for the notion of disturbance-related reproduction by certain tree tree certain by reproduction disturbance-related of notion the for Support

. .

Mean occurrence ( ( occurrence Mean

G. Forst. v. v. Forst. G.

(Ep)• (Ep)•

(Mt) (Mt)

Lour., Lour.,

± ±

D fudrtr tesi h ap forest Marpi the in trees understory of SD)

Eugenia palumbis palumbis Eugenia

Craig: Ecology of Limestone Forest Forest Limestone of Ecology Craig:

neo-ebudarum neo-ebudarum

lntsia bijuga bijuga lntsia

order by importance values. values. importance by order

8. 243 ± 286.4

189.8 ± 511.7 511.7 ± 189.8

175.9 ± 101.3 668.2 ± 395.7 76.9 ± 39.0 39.0 ± 76.9 395.7 ± 668.2 101.3 ± 175.9

35± 98 ± 43.5

33.7 ± 60.3 60.3 ± 33.7 44± 34 02± 68 16± 12 11.6 ± 56.8 ± 60.2 53.4 ± 44.4

85± 47 ± 28.5 46.9 ± 92.1 78.3 ± 160.6 160.6 ± 78.3 92.1 ± 46.9

30± 54 36 15.4 ± 13.0 29± 86 30 28.6 12.9 ±

14± 12 ± 11.4

33.9 ± 36.4 36.4 ± 33.9

13.9 ± 18.0 18.0 ± 13.9

. ± . 60± 90 0 19.0 ± 6.0 0.5 ± 0.2

. 77 6 7.7 ± 2.6

. 60 12 6.0 ± 2.9

. 10 ± 3.5

. 10 ± 4.4 2.8 2.8

. 2. 6 26.5 ± 8.8

. 1. 30 12.4 ± 7.4

5.5 5.5

Basal area area Basal

(m

C. C.

± ±

± 16.4 12.0 ± 38.1 2.4 ± 7.3 7.3 ± 2.4 38.1 ± 12.0 16.4 ±

2

/ha) Trees/ha Trees/ha /ha)

8.4 8.4

ramif[ora ramif[ora

.

.

. .

.

6 6

42 7

3. 5. 8 58.2 ± 36.1 6 1 12.0 ± 25.4 25.4 ± 12.0 1

9. 110 ± 90.3 9

.

. .

745± 9. 8. 44 ± 83.9 398.3 ± 764.5 1

may maintain itself in the forest by by forest the in itself maintain may

(Summerh.) Fosb. and and Fosb. (Summerh.)

Other more robust, commonly fruit- commonly robust, more Other

bijuga, bijuga,

Merr

P. grandis grandis P.

162.5 ± 130.2 16.3 ± 9.2 9.2 16.3 ± 130.2 ± 162.5

114.4 ± 156.6 17.7 ± 21.4 21.4 17.7 ± 156.6 ± 114.4

5. 70 ± 156.5

were one of the most abundant abundant most of the one were

12.0 ± 38.1 1.8 ± 5.4 5.4 ± 1.8 38.1 ± 12.0

66

6

.

.

.

.

.

. .

.

.

0 ± 19.0 19.0 ± 0

± 19 0±

0 ± 25.4 1.8 ± 3.6 3.6 ± 1.8 25.4 ± 0

0 ± 19.0 2.0 ± 6.1 6.1 ± 2.0 19.0 ± 0

.

4. 9 44.4 ± 2

1 ± 51.1 3.9 ± 6.4 6.4 ± 3.9 51.1 ± 1

1 ± 51.2 3.9 ± 6.3 6.3 ± 3.9 51.2 1 ±

1 ± 29.1 5.7 ± 3.7 3.7 ± 5.7 29.1 ± 1

1 ± 31.1 31.1 1 ±

, and and ,

eent bevd o vege­ to observed not were

.

. 0 0

and and

19 7 Maytenus thompsonii thompsonii Maytenus

.

8 11.4 ± 13.5 13.5 ± 11.4 8

, ,

D. latifolia. latifolia. D.

arranged in descending descending in arranged

Importance value value Importance

, ,

G. mariannae, mariannae, G.

13.4 ± 25.2 25.2 ± 13.4

0.7 0.7

2

I.I I.I

5.8 ± 4.9 4.9 ± 5.8

.

.

.

.

6 ± 1.9 1.9 ± 6

.

C. C.

0 0

1 ± 4.4 4.4 ± 1

5 ± 15.5 15.5 ± 5

6 ± 5

± ±

± 3.4 3.4 ±

± ±

ramiflora ramiflora

2.2 2.2

6.7 6.7

.

2 2

.

.

2 2

9 9

Many Many 91 91

L. L.

E. E.

Q. Q.

0 0

C: C:

0 0

Cl) Cl)

:::J :::J

Cl) Cl)

~ ~ .§ .§

1 1

0 0

20 20

40 40

100 100

60 60

120 120

80 80

140 140

Aglaia Aglaia mar­

Carica Carica papaya

Acacia Acacia confusa

at at transects 10 ar­

value value

A. A. DC., and

h h

de de Wit and

g g

importance importance

(L.) (L.)

Pisonia Pisonia grandis

-

e e

transect transect

(i). (i).

is is fed upon and probably dispersed by birds.

d d

Pisonia grandis grandis Pisonia

Micronesica 25(1), 1992 1992 25(1), Micronesica

C C

papaya papaya

C. C.

b b

basal basal area

Leucaena Leucaena /eucocephala

Benth. Benth. (introduced) limited was to transect, and 1 there- was

P. P. obovata, Ochrosia mariannensis

a a

D D

(L.) (L.)

ranged ranged from north (a) to south

Merr. Merr. based may, on their negative importance value ratio, in increase

o__,_-~ o__,_-~

Figure Figure 3. Basal area and importance value of

4000 4000

8000 8000

The The introduced

These are only preliminary preliminary data recruitment only on are limestone dynamics forest; These in

12000 12000

16000~------

gj gj

ti! ti!

Q) Q)

only only the fleshy-fruited

.E .E

Merr. Merr. occurred predominantly in the canopy (Figure 6), and therefore appeared (introduced) (introduced) in regular was the understory. Notably, of these introduced species,

to to have little reproductive success in this forest. However,

times times and in areas of limited disturbance. Albizia Albizia /ebbeck s s

of of mostly sexually reproducing, shade tolerant species are maintained during

species composition composition species is regulated by the frequency and intensity of external (i.e. after mechanical after mechanical injury are maintained in the system by disturbance, and a suite

typhoon) disturbance. A suite of vegetatively reproducing species that that typhoon) reproducing disturbance. vegetatively suite A species flower of also

.0 .0

as as survivorship, survivorship, and importance of vegetative propagation are needed. However, this this system. A model may be proposed for limestone forest dynamics: forest

for for a thorough assessment, data on such parameters as seed viability, dispersal, the the data provide initial insights into the mechanisms of forest maintenance in

iannensis iannensis

.§. .§.

.r::. .r::.

cu cu

the the forest canopy under conditions of low disturbance.

ing species, such such as species, ing

N-._ N-._ 92 92

species in the Marpi study area: area: study Marpi the in species above the Last Command Post, an area never cultivated, is a likely consequence likely consequence a is cultivated, never area an Post, Command Last the above

of a very large explosion. explosion. large very a of

Japanese Last Command Post of World War II, was heavily bombed during the the during bombed heavily was II, War World of Post Command Last Japanese

American invasion of Saipan. A circular patch of of patch circular A Saipan. of invasion American

(26.3% of the canopy importance values). The vicinity of this transect, near the the near transect, this of vicinity The values). importance canopy (26.3% the of

northern end of the study area had relatively high cover by introduced species species introduced by cover high relatively had area study the of end northern

the native woody vegetation of Mangaia, Cook Islands, this finding suggests suggests finding that this Islands, Cook Mangaia, of vegetation woody native the

native forest is resistant to invasion by alien species. Only the transect at the the at transect the Only species. alien by invasion to resistant is forest native

story. Like the similarly high percent native cover found by Merlin (1991) for for (1991) Merlin by found cover native percent high similarly the Like story. based on their importance values (Tables 1, 2), require further study to determine determine to study 1, further 2), (Tables require values importance their on based

their potential role in future forest composition. Based on importance values, values, importance on Based composition. forest future in role potential their

they presently comprise 6.4 6.4 comprise presently they

likeArtocarpus altilis), altilis), likeArtocarpus

production. production.

oeto nomn o n dfntv saeet o emd cnenn t re­ its concerning made be to statement definitive any for uncommon too fore

N--

! !

.c .c

ni ni

-

.c .c co co

m m

~ ~

n, n,

n, n,

E E

In addition to those located during sampling, I found the following tree tree following the found I sampling, during located those to addition In

Recently introduced species (not including prehistorically introduced species species introduced prehistorically including species (not introduced Recently

1000 1000

1500 1500

2000--r------, 2000--r------,

500 500

Figure 4. Basal area of canopy and understory understory and of canopy Basal area 4. Figure

arranged from north (a) to south south to (a) north from arranged

a a

although now oflimited significance significance forest limestone in the now oflimited although

D D

Craig: Craig: Ecology Limestone Forest of

± ±

C C

canopy canopy

7.5% of the canopy and 2.9 2.9 and canopy 7.5% the of

Annona reticulata reticulata Annona

Cynometra ramiflora ramiflora Cynometra

d d

(i). (i).

transect transect

e e

-

Cynometra ramiflora ramiflora Cynometra

f f

understory understory

L. L.

L. L.

g g

leucocephala leucocephala

itoue; ctee in- scattered (introduced;

± ±

h h

3.5% under­ 3.5% the of

at 10 10 transects at

on the cliffs cliffs the on 93 93

or­

(na­

Guet­

(DC.) (DC.)

v. v.

L. L.

Psycho­

Volkens Volkens

L. L.

Trema or­ Trema

Callicarpa Callicarpa

Casuarina Casuarina

(Endl.) F. von von F. (Endl.)

at at transects IO

Wedd. Wedd. (native; forest

Kurz Kurz (introduced; sin­

h h

f.) f.)

specimen specimen was combined

(introduced; (introduced; forest edge),

Hernandia sonora sonora Hernandia

L. L.

Kurz Kurz (native; in intermittent

Allophy/us timorensis timorensis Allophy/us

g g

Po/yscias grandiflora grandiflora Po/yscias

(Forst. (Forst.

Excoecaria agallocha agallocha Excoecaria

(L.) (L.)

understory understory

Streb/us pendulinus pendulinus Streb/us

f f

Guamia Guamia mariannae

-

e e

transect transect

P. hombroniana P. hombroniana

(j)) (j))

Bauhinia monandra monandra Bauhinia

d d

L. (native; (native; L. in intermittent stream valley),

(Planch.) (Planch.) Laut. (native; forest edge),

Muntingia ca/abura ca/abura Muntingia

Guamia Guamia mariannae

Pipturus argenteus argenteus Pipturus

Micronesica 25(1), 1992 1992 25(1), Micronesica

Markg. Markg. (native; scattered individuals},

canopy canopy

C C

] ]

Barringtonia asiatica asiatica Barringtonia

::

f

argentea argentea

b b

(Baill.) Fosb. Fosb. (native; (Baill.) scattered individuals) were encountered.

a a

(native; (native; scattered individuals),

Hibiscus tiliaceus tiliaceus Hibiscus

L. L. (native; scattered individuals},

Basal area area Basal of canopy and understory

(Bojer) (Bojer) Raf. (introduced; single tree at high elevation},

L. L.

Blume Blume v.

5. 5.

Muell.-Arg. (native; (native; Muell.-Arg. scattered individuals),

Cerbera dilatata dilatata Cerbera

arranged arranged from north (a) to south

(Burm.) (Burm.) Roehr. (native; forest edge),

(L.) (L.)

Figure Figure

Besides these Besides species, vegetative specimens identified tentatively as

100 100

200 200

300 300

400""T-"------, 400""T-"------,

tria hombroniana hombroniana tria On On the study transects, one possible

edge and and edge openings).

Blume (native; (native; Blume scattered individuals),

Muell. Muell. (native; southern end of study area only},

gle clump clump gle of individuals), and ientalis ientalis

fa fa

candicans candicans

as as ; ;

(native; (native; scattered individuals),

Delonix regia regia Delonix

stream stream valleys), tarda speciosa speciosa tarda

E E

thostichalis thostichalis

tive; several at slope base), base), at slope several tive;

equisetifolia equisetifolia

......

~ ~

dividuals), dividuals),

.c .c

al al

-

cii' cii'

cf:. cf:.

...... 94 94

limestone forest system retains some of its natural features. features. natural its of some retains system forest limestone

iual ntrs fseisdsrbtos n rltv bnac) u te uni­ the but abundance), relative and species distributions of terms in ticularly formity of its appearance even between islands suggested that the present present the that suggested islands between even appearance its of formity

teristics are likely in part a byproduct of human and feral animal activity (par­ activity animal feral and human of byproduct a part likely in are teristics

a similar species assemblage was found throughout. The existing forest charac­ forest existing The throughout. found was assemblage species similar a

elsewhere on Saipan and Tinian. Species proportions varied between sites, but but sites, between varied Species proportions Tinian. and Saipan on elsewhere

indicated a general similarity in appearance with low to mid-elevation forest forest mid-elevation to low with appearance in similarity general a indicated

in the figures, tables, and text. text. figures, and tables, the in

Eugenia reinwardtiana reinwardtiana Eugenia during their July flowering appeared to be be flowering to July appeared their during

with with

or fruiting or fruiting was between sampling distinguish I not during the observed period, did

-0.5 -0.5

Qualitative comparison of the Marpi forest with other limestone forests forests limestone other with forest Marpi the of comparison Qualitative

0.5 0.5

P. mariana mariana P.

-1-t-----,---,--r--T"",r-T-,---,---r-,--,--,--.---,---,-,--r--,,.....,.-,----,---,--,--,.._..,.---,-~-.----,------1 -1-t-----,---,--r--T"",r-T-,---,---r-,--,--,--.---,---,-,--r--,,.....,.-,----,---,--,--,.._..,.---,-~-.----,------1

Figure 6. Ratio of canopy and understory importance values for tree species in the the in species tree for values importance understory and canopy of Ratio 6. Figure

atively important forest constituents, whereas species toward the graph center center graph the toward species whereas constituents, forest important atively

are relatively unimportant. See Table l, 2 for abbreviations of species names. names. species of abbreviations for 2 l, Table See unimportant. relatively are

lf)udrtr iprac vle Hne pce t h rp egsae rel­ are edges graph the at species Hence, value. importance understory (left)

arranged from greatest (left) to lowest (right) canopy importance value. Species Species value. importance canopy (right) lowest (left) to greatest from arranged

predominating in the understory are arranged from greatest (right) to lowest lowest to (right) greatest from arranged are understory the in predominating

Marpi limestone forest. Species predominating in the canopy (values (values canopy the in predominating Species forest. limestone Marpi

Pg Pg

lb Pr Mm Ev No Al Aa Ac Cs Ps Ag Pd Po Gm Gm Po Pd Ag Ps Cs Ac Aa Al No Ev Mm Pr lb

Bartl. Bartl.

1

D1

1 1

Ft

(Bl.) DC. and and (Bl.) DC.

ex. ex.

1 1

Fp

. .

DC. in analyses. Furthermore, because no flowering flowering no because Furthermore, analyses. in DC.

r-

Craig: Craig: Ecology Forest Limestone of

1 1

Cp Cp

'u 'u

tree species species tree

E. pa/umbis. pa/umbis. E.

Pt Pt

E. pa/umbis, pa/umbis, E.

Am Dd Mt Mc Om Om Mc Mt Dd Am

Most individuals, as verified verified as individuals, Most

and are reported as such such as reported are and

Ep Ep

> >

1

AI AI

0) are are 0)

'er 'er 95 95

& &

rein­

Aglaia Aglaia

Gilg Gilg

Elaeocarpus Elaeocarpus

found found

Eugenia Eugenia

41: 41: 191-199.

Pisonia Pisonia umbel­

Wildt. Serv. Rep. Rep. Serv. Wildt.

and and

& &

Indo-Pacific species, species, Indo-Pacific

L., L.,

(1976) (1976)

spp., spp.,

Marianas genus. Some Some Marianas genus.

1970) 1970)

Micronesian Micronesian forest bird sur­

1970) 1970)

Muell.-Arg. were characteristic. characteristic. were Muell.-Arg.

Pandanus Pandanus

(Raf.) (Raf.) Kost. and

1986. 1986.

forests forests also may be in strand com­

Cycas circinalis Cycas circinalis

found that limestone forest dominants dominants that forest limestone found

on on Saipan.

to to be the dominant limestone forest spe­

1973) 1973)

References References

Krauska Krauska assisted with work. field I especially

E. Merr., E. Merr.,

The use of distance measures in phytosociological phytosociological in measures distance of use The

K. K.

Acknowledgments Acknowledgments

V. J. J. V. Wildman.

Micronesica Micronesica I), 992 25( I

F. F. galilai

Mammea Mammea odorata

than than the elevation lower forests, and had high den­

& &

Claoxy/on Claoxy/on marianum

1956. 1956.

Raulerson, Raulerson, D. Steadman, and S. Villagomez G. Wiles

37: 37: 451-460.

L. L.

odorata-dominated odorata-dominated

1989) 1989)

. .

M

Ramsey Ramsey

Guamia Guamia mariannae

L. L.

T. Curtis. Curtis. T.

Saipan, Tinian, Agiguan, and and Rota. Tinian, Fish U.S. Saipan, Agiguan,

Young Young

Stunted Stunted cloud forest in Taveuni, Fiji. Sci. Pacific

J. J.

and and

& &

Similar Similar

1982: 1982:

Guettarda Guettarda speciosa, Hernandia /abrynthica, Fagraea gali/ai

Macaranga Macaranga thompsonii

1960, 1960,

1987. 1987.

J. J.

vey, vey,

sampling. sampling. Ecology

I I thank M. Lefor,

(Forst.) Seemann, and and Seemann, (Forst.)

The The native limestone forest of the Marpi region may be characterized as

Merr. joined joined Merr. these as common tree The species. latter are 3 rare species on

In contrast to this study, Moore ( Moore study, this to contrast In

In contrast to these forests, remnant limestone forest at the highest elevations elevations at remnant the highest limestone forests, forest these to contrast In

Engbring, J., J., F. Engbring,

Cottam, G. Cottam,

Ash, Ash,

Robertson Robertson Federal Aid to Wildlife.

Mariana Mariana Islands, Division of Fish and Wildlife, in conjunction with Pittman­

in in the Pacific. This work was funded by the Commonwealth of the Northern

thank thank my wife, Barbara, for her support and encouragement on all my studies

for for their insights concerning this study. L. Raulerson verified my plant identifi­

cations, cations, and V. Camacho and

species. species.

Despite centuries of human-related human-related centuries Despite of disruption, composition forest remains over­

whelmingly native, suggesting that that native, whelmingly native suggesting forest is resistant to invasion by alien

fected by by the fected frequency and severity of typhoons and other natural disturbance.

to recruit successfully into into to recruit a successfully forest closed canopy. In the of absence human and

feral feral ungulate disturbance, and relative proportions of these may species be af­

species may may be species maintained in the system by disturbance, others whereas appear

and an understory and an understory dominated an endemic by (Stone

having a canopy dominated dominated (Stone widespread canopy a two by having

wardtiana. wardtiana.

of of Rota and Guam appear more diverse than those of Saipan, but whether this

represents represents the original condition of the forests is uncertain. marianennsis marianennsis

munities munities on Saipan. At Hilaan Beach, Guam Muniappan

cies. In In cies. the general, more southerly, apparently xerophytic less limestone forests

at at Pagat Point, Guam were

Saipan, Saipan, and I have not found

Benedict, Benedict,

On On Rota,

lifera lifera

sities sities of epiphytic lichens, mosses, ferns, and orchids. The forest floor was also

typically moss-covered, moss-covered, and typically tree such species as

strong strong in differences appearance. These fog-prone areas are cooler and wetter

(Fosberg (Fosberg

of Mt. Tapotchau, Mt. Tapotchau, Rota elevation and of Saipan, exhibited the high plateau of forest

joga joga 96 96

Young, F. J. 1989. Soil Survey of the Islands of Aguijan, Rota, Saipan, and Tinian, Tinian, and Saipan, Rota, of Aguijan, Islands the of Survey Soil 1989. J. F. Young,

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Moore

Merlin, M. D. 1991. Woody vegetation on the raised coral limestone ofMangaia, ofMangaia, limestone coral raised the on vegetation Woody 1991. D. M. Merlin,

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bats bats

etns Pcfc cec 4: 166-185 41: Science Pacific settings.

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ation. Pacific Sci. 39: 150-170. 150-170. 39: Sci. Pacific ation.

Micronesica 9: 45-58. 45-58. 9: Micronesica

southern Cook Islands. Pacific Sci. 45: 131-151. 131-151. 45: Sci. Pacific Islands. Cook southern

eastern Caroline Islands. Micronesica 18: 109-120. 109-120. 18: Micronesica Islands. Caroline eastern

sectivorous birds in a northern hardwood forest. Oecologica 48: 31-35. 31-35. 48: Oecologica forest. hardwood northern a in birds sectivorous

trosideros trosideros

lynesian birds through habitat mapping and species translocation. Cons. Biol. Biol. Cons. translocation. species and mapping habitat through birds lynesian

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119. 119.

B. B.

, ,

P. H. 1973. Composition of a limestone forest community on Guam. Guam. on community forest limestone a of Composition 1973. H. P.

(Pteropus (Pteropus mariannus)

C. 1970. The flora of Guam of flora The 1970. C.

J. J.

. .

R., M. M. R.,

& &

. .

& &

forests. Ecology 71: 1 1 176-1184. 71: Ecology forests.

.W Seda. n rs. h ptnil o cnevto o Po­ of conservation for potential The press. in Steadman. W. D.

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