Table Of ContentSelbyana 17: 58-70
DISTRIBUTION AND CONSERVATION OF
EPIPHYTES ON THE YUCATAN PENINSULA
INGRID OLMSTED AND MAURO GOMEZ JUAREZ
Centro de Investigaci6n Cientifica de Yucatan, A.P. 87, Cordemex,
Merida, Yucatan, Mexico
ABsTRACT. Approximately 100 species of epiphytes of the Orchidaceae, Bromeliaceae, Cactaceae, Ar
aceae, Piperaceae and Polypodiaceae occupy the canopy and tree trunks of the various tropical forests of
the Yucatan Peninsula. We established the geographic distributions of most of these epiphytes, and at the
same time assigned them to different habitats: tall and medium-statured semi-evergreen and subdeciduous
forest, and low-statured deciduous and seasonally inundated forests, as well as mangroves. The number of
epiphyte species vary between forests. The low-statured inundated forests, unique to the Peninsula and the
least disturbed, are home to about 56% of the epiphyte species, while the tall semi-evergreen forest hosts
approximately 78%. Perturbations oft he tropical forests are widespread but patchy. For example, in southern
Quintana Roo between 1975 and 1990, the increase (hectares) in agriculture and cattle ranching was 80%
whereas in secondary vegetation it was 48%. With> 50 % of the original forest gone, the Peninsula's eleven
protected natural areas occupying 10% of the surface area, will give some protection to the epiphytes.
INTRODUCTION Peninsula. In this paper, we describe the distri
bution and state of conservation of the epiphytes
Today's concern about the loss oftropical for and their habitat in this area.
ests has given rise to a large number of publi
cations on the subject (Dirzo & Garcia 1992, Tropical Forests of the Yucatan Peninsula
Houghton 1994, Krummer & Turner 1994, Ba The major potential vegetation types of the Pen
ker 1989 ) in every country within the tropics. insula were described by Miranda (1958). FIGURE
In a recent account of tropical deforestation rates 1 is a presentation of the potential forest types
throughout the world by the Environmental Pro assuggested by INEGI in 1981.
tection Agency, Mexico was listed with the high The Peninsula has five types of forest. From
est annual rate (Cairns pers. comm.). northwest to southeast, they include low-sta
The forests on the Yucatan Peninsula are part tured deciduous forest, medium-statured sub
of the major tropical vegetation in Mexico's deciduous forest, medium-statured, semi-ever
southeast. Once boasting a 90% forest cover, the green forest, tall semi-evergreen/evergreen forest
three states of Yucatan, Campeche and Quintana and low-statured inundated forest. The climatic
Roo may actually have a total of 1 million hec gradient with regard to precipitation influences
tares of mature forest left today, of which 99% the distribution of the forest; the annual rainfall
are located in Quintana Roo and Campeche. The increases from about 500 mm in the northwest
major pressures are intensive cattle ranching, to 1500 mm in the southeast and southwest.
large-scale commercial agriculture, tourist de Low-Statured Deciduous Forest-This forest
velopment, urbanization, timber harvest and il only occurs in the northwestern portion of the
legal collection of epiphytes. However, the dis state of Yucatan, on rocky entisols with very low
turbed forest may not be irrevocably converted water retention. The trees lose their leaves during
to agriculture, cattle ranching, urbanization or the spring dry season when many species flower
tourism, and has the potential of eventually re (Olmsted et al. 1994). The Leguminosae is the
verting to mature forest. dominant family in this community. The most
The epiphyte community ofthe Yucatan Pen common tree species are Bursera simarouba,
insula is composed of species in the Orchidaceae, Caesalpinia gaumeri, Acacia pennatula, Meto
Bromeliaceae, Piperaceae, Araceae, Cactaceae pium brownei, Gymnopodiumj!oribundum, Cae
and Polypodiaceae. By comparison with other salpinia yucattlnensis, Plumeria obtusa, etc., with
Mexican epiphyte communities and certainly a total of about 50 species12000 m2•
those of other South American countries, the ep The canopy is open, with the tallest trees
iphytes of the Yucatan Peninsula are not very reaching 10m, and an average tree height of 6-
diverse. We estimate 107 species for the above 8 m. Many trees have branches starting very low
mentioned families. on the stem. Coppicing is common in this forest.
The disturbance and loss of forests during the The composition includes a number of species
last 20 years, which coincides with a burst of with spines.
development in many sectors, has caused the loss Medium-Statured Subdeciduous Forest-The
of habitat for many epiphytes on the Yucatan subdeciduous forest was determined by Miranda
58
1996] OLMSTED & GOMEZ-JUAREZ: YUCATAN PENINSULA EPIPHYTES 59
FIGURE 1. Potential forest vegetation on the Yu FIGURE 2. Distribution of low-statured seasonally
cat{m Peninsula: 1. Low-statured deciduous forest 2. inundated forest on the Yucatan Peninsula.
Medium-statured subdeciduous forest 3. Medium-sta
tured semi-evergreen forest 4. Tall semi-evergreen or
evergreen forest.
chiana, Simarouba glauca, Swartzia cubensis,
Lonchocarpus castilloi, Aiseis yucatanensis, and
(1958) as one in which 50-75% oft he individuals Sabal yapa.
lose their leaves during the dry season. It occurs Tall Semi-Evergreen Forest-This forest type
in the eastern portion of Yucatan (FIGURE 1), occurs in the very southern portion of the Pen
northern Campeche and a small portion of west insula on the Guatemala and Belize borders. Al
ern Quintana Roo. Precipitation oscillates be most all of the individuals keep their leaves
tween 1000 and 1200 mm per year. However, throughout the year. Structurally the tallest for
this forest type may occur in small extensions if est, it reaches up to 30 m. Trees do not start to
edaphic conditions are appropriate, within the branch until at least halfway up the straight trunks
same area as the semi-evergreen forest. Trees or sometimes not until the last third. Many of
reach up to 18 m, and the density of trees and the trees have buttresses. Woody vines abound.
their cover are less than in the semi-evergreen The dense canopy does not allow much light to
forest. Epiphytes and vines are not very com penetrate to the forest floor which makes for a
mon. less abundant understory of palms and ferns.
Some of the more common tree species are The most important species are Swietenia ma
Vitex gaumeri, Brosimum alicastrum, Piscidia crophylla, Brosimum alicastrum, Talisia olivae
piscipula, Enterolobium cyc!ocarpum, Caesalpi jormis, and M anilkara zapota. Other species fre
nia gaumeri, and Cedrela odorata. Other im quently represented are Pouteria campechiana,
portant species are Cochlospermum vitifolium, Swartzia cubensis, Ceiba pentandra, Lysiloma
Gliricidia sepium, and Bursera simarouba. As for latisiliquum, Andira inermis, and Lonchocarpus
deciduous forest, very little area is left today with castilloi. Cryosophila argentea, and Sabal maur
mature subdeciduous forest. iliformis are some of the palms present in this
Medium-Statured Semi-Evergreen Forest-As forest.
in Figure 1, this is the most extensive forest type Low Inundated Forest-This forest is consid
on the Yucatan Peninsula. It is structurally very ered typical of the Yucatan Peninsula (FIGURE
similar to the tall evergreen forest. This forest 2), even though it is the least extensive of the
type develops in a climate with between 1100 forest types. Several different communities of this
and 1400 mm of rain over shallow entisols and forest type are known (Olmsted and Duran in
rendzinas as well as slightly deeper kankab. The press). The low seasonally inundated forest oc
trees reach between 15 and 25 m and develop curs in mosaic fashion within the tall and me
anywhere from 30-50 m 2/ha of basal area. Ac dium-statured forests, most of the time in small
cording to Miranda (1958), 25 % ofthe trees lose areas, especially along the coast. It is not a climax
their leaves during the dry period. forest type. Toward the south, this forest occurs
The typical tree species of this forest is Man inland in larger tracts. They occur in slight de
ilImra zapota, from which chicle gum is pro pressions which have poor drainage and cause
duced. Other common species are Brosimum al inundations during the rainy season. The forest
icastrum, Talisia olivaejormis, Pouteria campe- is semi-evergreen. Usually one tree species dom-
60 SELBYANA [Volume 17
inates in these associations and the overall di tification, and evaluated the conservation of the
versity is low by comparison to the other tropical habitat and the state of the populations.
forest types on the peninsula. Species that grow We listed epiphyte species by their family,
here have to be adapted to prolonged inundation habitat(s), and geographic distribution. For all of
and sometimes prolonged dry periods. The tallest the epiphytes found we noted the occurrence to
trees reach 10-12 m, but the average height is the closest village on a topographic map. The
6-8 m or less. The trunks of the trees are often information was then put on a map divided into
twisted, with branching at soil level and many quadrats of liz degree on the side. The habitats
species possessing spines. were identified according to Olmsted and Duran
Each community ofthis forest type has a dom (1990). The conservation status of the habitats,
inant species, such as Haematoxyium campe where we found epiphytes was determined by
chianum in the tin tal (logwood community), or the structure and composition ofthe community.
Bucida buceras in the pucteal (from 'pucte' in For instance, a secondary forest usually did not
Maya ), or Dalbergia glabra in the mucal (from have any epiphytes. Most of the forests were ma
'muk' in Maya). One important aspect of these ture, with perturbations such as selective cutting
communities is the abundance of epiphytes, es of trees for timber and for domestic use by in
pecially orchids and Tillandsia species. Other tree digenous people.
species are Erythroxylum confusum, E. rotun Size of populations varied from one habitat to
dijolium, Byrsonima bucidaefolia, Jacquinia au the next. Because of our previous studies ofbro-
rantiaca, and Cameraria lalijolia. . meliads and orchid distributions (Olmsted &
Mangroves-The mangrove habitats on the Duran 1986, Zimmerman & Olmsted 1992), we
Peninsula are divided into three major catego could judge the relative size of populations. For
ries: fringe, basin and dwarf mangroves. Rhizo instance, if we found about 10 plants or groups
phora mangle, Avicennia germinans, and Lagun of plants on different trees in a small area in the
cularia racemosa are the mangroves growing in inundated forest, we considered the species to
these communities along with Conocarpus er have a good population size. The same number
ecta. The coastal fringe and slightly more inland ofe piphytes was required over a much larger area
basin mangroves reach heights of up to 15 m, in the medium-statured or taller forest to be con
but most grow to 8-10 m. Dwarf mangroves are sidered a sufficient population size.
only 1.5-4 m, with varying densities. Epiphytes The state ofthe forests from the 1970's to the
occur mostly in dwarf and fringe mangrove com 1990's on the Peninsula was examined with sat
munities, growing on red and white mangroves ellite images, aerial photography and groundtru
as well as on Conocarpus. thing. This vegetation study is part of an ongoing
project with EPA and Instituto de Geographia
of UNA M. We considered only the Mexican por
tion of the Yucatan Peninsula in the geographic
METHODS
distributions.
We studied the epiphytes of the families Or
chidaceae, Bromeliaceae, Piperaceae, Araceae,
Cactaceae and Polypodiaceae. As a basis for the
RESULTS AND DISCUSSION
presence of the epiphytic orchids, we used the
list by Andrews & Gutierrez (1988) for the Yu Epiphytes-During our field work, we did not
catan Peninsula and the updated list of orchids see every species that occurred in our checklists
for Mexico by Soto Arenas (1988). We also looked (Andrews & Gutierrez 1988, Soto 1988, Torres
at the specimens and their origin in the CICY 1991, Garcia-Franco 1987). Some of the rare
Regional Herbarium. The locations of collected orchids, that were originally found in one or two
live specimens in the CICY Regional Botanical places on the peninsula, are examples of species
Garden were used as well. For Bromeliaceae, we that we have been unable to relocate. Based on
used Garcia-Franco (1987), as wen as the Et our visits and on literature, we list 63 epiphytic
nofiora Yucatanense (Sosa et at. 1985). The latter species of Orchidaceae, 19 species of Bromeli
was also used for the Piperaceae, Araceae and aceae, 5 species of Cactaceae, 2 species of Pi
Cactaceae. For ferns, we referred to the bachelor peraceae, 2 species of Araceae and 10 ferns (TA
thesis by Silvia Torres (1991). Other references BLE 1).
which helped us with identification and distri The number of epiphytes found to date on the
bution were Gardner (1982) and volume 6 of peninsula is probably conservative for several
Flora Mesoamericana. reasons. First, the Orchidaceae and Bromeli
During 1992-1994, we made numerous field aceae are better known than the other families
trips throughout the Yucatan Peninsula looking treated here, so that we would expect some ferns,
for epiphytes. We noted their location and iden- cacti, peperomias and anthuriums to be unac-
1996] OLMSTED & GOMEZ-JUAREZ: YUCATAN PENINSULA EPIPHYTES 61
counted for on the peninsula. We expect that the The low inundated forest has few fern species,
orchids and bromeliads will increase slightly as as far as we could ascertain.
more species are encountered in the southern The five epiphytic cacti are quite clearly sep
forests along the border with Guatemala and Be arated by habitat, with Epiphyllum phyllanthus
lize. (Between 1988 and 1994, five more species . and Rhipsalis bacci/era only occurring in the tall
of orchids were added to the list for the penin and medium-statured semi-evergreen forest, the
sula.) However, some of the orchids which have two Selenicereus species being almost generalists,
not been found again during the last 10-20 years and the edible Hylocereus growing in the decid
may have to be deleted, because they probably uous forest.
do not exist here anymore. (Joann Andrews, from We do not have sufficient habitat information
Pronatura A.c., has worked on orchids of the for Piperaceae and Araceae. Our observations
Peninsula for the last 25 years and estimates that suggest that the two peperomias and Anthurium
50% of the populations of orchids have disap schlechtendalii are found mostly in the semi-ev
peared.) ergreen forests.
The environmental differences of the forest
Distribution of Epiphytes by Habitat-TABLE types determine to a great extent the richness of
1 shows our assignment of the epiphytes to the species and abundance of individuals of epi
different habitats. We should mention that even phytes. The tall forest or semi-evergreen forest
though it is possible to find a certain species in and its medium-statured variety provide shade
a certain habitat once, it does not mean that it and humidity in their closed canopy. The low
is the usual habitat for that epiphyte. For in inundated forest has an open canopy throughout
stance, several epiphytes, whose major habitat is most ofthe peninsula (Olmsted & Duran 1986),
either the semi-evergreen or inundated forest, but the canopy tends to close in the south, when
also occur infrequently in the subdeciduous for Bucida buceras is the dominant tree species. The
est; and this information is included here. subdeciduous and deciduous forests are much
We classified epiphytes that occur in almost drier than the other forest types. The deciduous
all forest types as generalists (e.g., Aechmea brac forest tends to have a discontinuous canopy, let
teata). Others, such as Epidendrum isthmi, ting iIi large amounts of sunlight. The subdeci
grow only in one habitat. TABLE 2 indicates the duous forest is also more open than the semi
total number of epiphytes/family that occur in a evergreen forest.
certain habitat. For the orchids, the tall forest is The low inundated forest is dominated by dif
the most important habitat, followed by the low ferent tree species which have morphological
inundated and the medium-statured forests. Sev characteristics that make them very good pho
eral points should be made here that are not rophytes (Olmsted & Duran 1986). The branch
obvious from the results. Although the tall forest ing architecture and small spines of Bucida spi
has the highest diversity, the inundated forest nosa and B. buceras (Dejean et at. 1995) seem
has the greater abundance ofi ndividuals/species. to catch the seeds of Tillandsia. While annually
The tall forest occurs only in the south, while the these forests may completely dry out for extend
inundated forest occurs all over the peninsula. ed periods in the northern half of the Peninsula,
However, the canopy of the inundated forests is such dry periods are shorter and less pronounced
higher in the south and consequently much richer in the south, resulting in higher epiphyte richness
in orchid specids than in the north. in the southern low inundated forests than the
The OrchidaCeae is the most diverse family, northern ones.
but also represents the greatest number ofs pecies
which we did not locate (about 20 species); how Geographic Distribution of Epiphytes - Based
ever, they are still included, because we were not on our field visits, current literature, and other
able to visit all the sites previously explored by investigators' results, we made geographic dis
other researchers. tribution maps for most species. However, in
The Bromeliaceae has 19 species in 3 genera, order to reduce the number of maps for this pa
with 17 species in the genus Tillandsia, and is per, we produced some general maps for several
most abundant in the low-statured inundated species that had similar distribution patterns.
forest. Though the difference in species between Orchids, in particular, had similar distributions.
the inundated and the tall and medium-statured For some orchids, for which we only had one or
evergreen forest is only 2, the abundance of in two points, we. were unable to map those for this
dividuals is greatest in the inundated forest. paper. .
We have insufficient habitat information about Orchidaceae-FIGURES 3-7 are an indication
the 10 fern species. However, the medium-sta of some distribution patterns. Eight species occur
tured and tall semi-evergreen and evergreen for over most of the peninsula (FIGURE 3), in most
ests are the dominant habitat of these species. of the forest types. We should point out that in
62 SELBYANA [Volume 17
TABLE 1. Epiphyte species by family and habitat. Forest types: LIF = Low inundated MSD = Med-stat.
subdeciduous. MSE = Med-stat. semi-evergreen, LDF = Low deciduous, TR = Tall evergreen, MG =
Mangroves. + Indicates not seen by authors.
LIF MSD MSE LDF TR MG
Fam. Orchidaceae
1. Brassavola eueullata (L.) R. Br. * * *
2. B. nodosa (L.) Lind!. * * *
3. Brassia cf. maculata R. Br. + *
5. Bulbophyllum oerstedii (Rchb. f.) Hems!. + *
6. Campyloeentrum micranthum (Lind.) Rolfe * * *
7. C. paehyrrhizum (Rchb. f.) Rolfe * * *
8. C. peoppigii (Rchb. f.) Rolfe * * *
9. C. porreetum (Rchb. f.) Rolfe * *
10. Catasetum integerrimum Hook. * * * *
11. Coryanthes cf. picturata Rchb. f. + *
12. Dimerandra emarginata (G. Mey.) Hoehne + *
13. Eneyclia alata (Bateman) SchUr. * * * * *
14. E. belizensis (Rchb. f.) SchUr. * * * * *
15. E. boothiana (Lind!.) Dressler * * *
16. E. bractescens (Lind!.) Hoehne * *
17. E. cochleata (L.) Lemee * *
18. E. livida (Lind!,) Dressler + *
19. E. nematoeaulon (A. Rich.) Acuna *
20. E. papillosa (Bateman) Aguire-Olavarrieta + * *
21. Epidendrum ciliare L. + *
22. E. difforme Jacq. * * *
23. E. imatophyllum Lind!. + *
24. E. isthmi SchUr. *
25. E. noeturnum Jacq. * * *
26. E. raniferum Lind!. + * *
27. E. rigidum Jacq. * * *
28. E. secundum Jacq. * *
29. E. stamfordianum Batem. * * *
30. E. strobiliferum Rchb. f. + *
31. Gongora unicolor Schltr + *
32. Ionopsis utrieularioides (Sw.) Lind!. * *
33. Isoehilus carnosif/orus Lind!. * * *
34. Laelia rubeseens Lind!. * *
35. Leoehilus scriptus (Scheidw.) Rchb. f. + *
36. Maxillaria aciantha Rchb. f. + *
37. M. erassifolia (Lind!.) Rchb. f. + *
38. M. tenuifolia Lind!. * *
39. Mormoiyea ringens (Lind!.) Schltr. *
40. Myrmeeophila cf. brysiana (Lem.) G.c. Kenn. + *
41. M. tibicinis (Bateman) Rolfe * * * * *
42. Nidema boothii (Lind!.) SchUr. * * *
43. Notylia cf. barkeri Lind!. * * *
44. Oncidium aseendens Lind!. * * * * *
45. O. earthagenense (Jacq.) Sw. * * * *
46. O. eebolleta (Jacq.) Sw. * *
47. O. lindenii Brongn. + *
48. O. iuridum Lind!. + *
49. O. sphacelatum Lind!. * *
50. Ornithocephalus inf lexus Lindl. * *
51. Pleurothallis grobyi Batem. ex Lind!. *
52. P. tikalensis Correll & C. Schweinf. * *
53. P. yueatanensis Ames & C. Schweinf. + * *
54. Polystaehyafoliosa (Hook.) Rchb. f. * * *
55. Ponera striata Lind!. * *
56. Rhyneholaelia digbyana (Lind!.) Schltr. * * * * *
57. Scaphyglottis behrii (Rchb. f.) Hems!. *
58. S. major (C. Schweinf.) Correll + *
59. Stelis gracilis Ames. + * *
1996] OLMSTED & GOMEZ-JUAREZ: YUCATAN PENINSULA EPIPHYTES 63
TABLE 1. Continued.
LIF MSD MSE LDF TR MG
60. S. ciliaris Lindl. *
61. Trichosalpinx!oliata (A. Griseb.) Luer + *
62. Trigonodium egertonianum Batern. ex Lindl. * *
63. Vanilla odorata Pres1 * *
64. V. planifolia G. Jackson * * *
Farn. Brorneliaceae
1. Aechmea bracteata (Sw.) Griseb. * * * * * *
2. Catopsis berteroniana (Schultes f.) Mez * *
3. Tillandsia balbisiana Schultes f. * * * * *
4. T. brachycaulos SchItdl. * * * * *
5. T. bulbosa Hook. * * *
6. T. dasyliriifolia Hook. * *
7. T. elongata var. subimbricata (Baker) L. B. Sm. . *
8. T. !asciculata Sw. * * * *
9. T. !estucoides Brong. ex Mez * * *
10. T. f/exuosa Sw. *
11. T. paucifolia Baker *
12. T. polystachia (L.) L. * *
13. T. pseudobaileyi C. S. Gardner * * *
14. T. recurvata (L.) L. * *
15. T. schiedeana Steud. * * * * *
16. T. streptophylla Scheidw. ex Morren * * * *
17. T. usneoides (L.) L. * * * * *
18. T. utriculata L. *
19. T. variabilis Sch1tdl. * * *
Fam. Polypodiaceae
1. Adiantum tenerum Sw. * * *
2. Campyloneurum phyllitidis (L.) Presl * *
3. Microgramma nitida (1. Smith) A. R. Smith * * * *
4. Nephrolepis biserrata (Sw.) Schott * *
5. Nephrolepis exaltata (L.) Schott * *
6. Pecluma!erruginea (Mart. & Gal.) M. G. Price * *
7. Phlebodium decumanum (Willd) J Smith * *
8. Polypodium polypodioides (L.) Watt. * * * *
9. Polypodium triseriale Sw. * *
10. Vittaria lineata (L.) J. E. Smith * * *
Fam. Cactaceae
1. Epiphyllum phyllanthus (L.) Haworth * * *
2. Hylocereus undatus (Haworth) Britton & Rose * * *
3. Selenicereus donkelaarii (Salm-Dyck) Britton & Rose * * * * *
4. S. testudo (Karw.) Buxbaum * * *
5. Rhipsalis baccifera (J. Miller) W. T. Stearn * *
Fam. Piperaceae
1. Peperomia crassiuscula Millsp. * * *
2. P. obtusifolia (L.) Dietr. * * *
Fam. Araceae
, 1. Anthurium schlechtendalii Kunth * * * *
2. Anthurium sp. * * * *
the central portion of Yucatan, where there is tall semi-evergreen and inundated forests, an
only secondary vegetation derived from low de other 12 species (FIGURE 4) are broadly distrib
ciduous forest, these orchids do not exist. uted. Another six species (FIGURE 5) only occur
In an area that covers practically all oft he state in the very southern portion of the peninsula, in
of Quintana Roo and the southern portion of the tall semi-evergreen forest. However, as in
Campeche, where we find medium statured and dicated in TABLE I, there are many species that
64 SELBYANA [Volume 17
TABLE 2. Total number of epiphytes per family and habitat.
LIF MSD MSE LDF TR MG
Orchidaceae 35 10 32 5 52 3
Bromeliaceae 14 9 12 9 10 4
Polypodiaceae 3 3 10 10
Cactaceae 3 2 5 2 4
Piperaceae 2 2 2
Araceae 1 2 2
Total number of epiphytes
per habitat 58 25 63 16 80 7
occur in the tall forest, where we lack geographic T. dasyliriifolia (FIGURE 13) have a coastal dis
information about them. For instance, Dean, Or tribution in hammocks and inundated forests as
tega and Andrews (unpubl.) list 50 epiphytes for well as in mangroves, but do not occur inland,
Calakmul Biosphere Reserve (4 are new registers except in some of the extensive low inundated
for the Peninsula). Calakmul has the three most forests (FIGURE 2). Tillandsia variabilis (not
important habitats for orchids, but we do not mapped), which grows mostly in the subdeci
know exactly where they occur. duous forest, surrounded by semi-evergreen for
However, other species, such as Laelia rubes est, and in the drier semi-evergreen forest, occurs
cens, seems to occur only in the western portion mostly in central Quintana Roo and central
of the peninsula, in the drier forests. The newly Campeche.
registered orchid for the peninsula, Epidendrum Tillandsia paucifolia, T. polystachia and T.
isthmi, only occurs in a small area of the tall utriculata (not mapped) have only two or three
forest on the Belizean border. Epidendrum im point distributions in the deciduous forest ofYu
atophyllum, several Campylocentrum species and catan for the first two and the inundated forest
the rarer Epidendrum and Encyclia species would on the island of Cozumel for the latter one. Til
have distributions like FIGURE 7, just one or two landsia pseudobaileyi (not mapped) occurs com
points. monly in the inundated forest of Quintana Roo
The geographic distribution of the orchids on and Campeche. Catopsis berteroniana (not
the Yucatan Peninsula is concentrated in the mapped) has currently a discontinuous distri
states of Quintana Roo and Campeche for two bution between northern Quintana Roo, Sian
main reasons: the state of Yucatan is very dis Ka'an and western Campeche.
turbed, and the deciduous and subdeciduous for Where epiphyte species of certain forest types
ests that grew there are not major orchid habitats. today show discontinuous distributions, we sug
If orchids do occur in northern Campeche and gest several reasons; the once continuous habitat
Yucatan, it is mostly along the coast where there is now disturbed, the habitat is very restricted
are inundated forests and semi-evergreen ham and not continuously distributed, our geographic
mocks. distribution information is not sufficient, or the
Bromeliaceae-The most common species of distribution is naturally disjunct.
this family is Aechmea bracteata, occurring in all Cactaceae, Piperaceae, Araceae and Polypo
vegetation types over the whole peninsula diaceae-The species of the Cactaceae are in
(FIGURE 8). Tillandsia Jasciculata (FIGURE 9) is dicated in FIGURES 14-16. Selenicereus donke
also common, occurring along with T. brachy laarii occurs over most of the peninsula in most
caulos, T. balbisiana and T. schiedeana. Certain habitats, while Selenicereus testudo seems to be
Tillandsia species, such as T. elongata var. sub restricted to the more humid forests in Quintana
imbricata (FIGURE 10), only occur in a small area Roo and Campeche. Epiphyllum phyllanthus
of the deciduous and subdeciduous forest in the seems to have a similar distribution to S. testudo
state of Yucatan. TillandsiaJestucoides (FIGURE in the semi-evergreen forest. Rhipsalis baccifera
11) grows in the tall and medium semi-evergreen is a rare species today and has a disjunct distri
forest in the very southern portion of Quintana bution. Hylocereus occurs in the deciduous forest
Roo and probably Campeche. Tillandsia f/exu types in Yucatan and scantily in the semi-ever
osa (FIGURE 12), only registered in 1984 for the green forest of the other two states.
Peninsula, was found in the seasonally inundated The peperomias (not mapped) also have a wide
forest in northeastern and central Quintana Roo. distribution, occurring in Quintana Roo and
Tillandsia bulbosa (not mapped) does not occur Campeche and much less in Yucatan. .
north of Sian Ka'an. Tillandsia streptophylla and Anthurium schlechtendalii is widely distrib-
1996] OLMSTED & GOMEZ-JUAREZ: YUCATAN PENINSULA EPIPHYTES 65
---
'-"' "
./
/. ,,/1 j
\ , // I /
.i
( I 'tv'/ ~
l) I ~ t;
,
!
tdii ~~. .... . r-5 ,!I -.-. f~11' Ii :(vj
\: -, i ..-,
"-. --. _. _. . 11 {, 7
FIGURES 3-7. Distribution patterns of orchid species on the Yucatan Peninsula: 3. Encyciia belizensis. E.
alata. Oncidium ascende ns. O. carthagenense. Rhyncholaelia digbyana. Brassavola nodosa. Catasetum integer
rimum. Myrmecophila tibicinis. 4. Vanilla odorata. Brassavola cucullata. Encyciia boothiana. E. cochleata.
Pleurothallis grobyi. Epidendrum rigidum. E. difforme. E. stamfordianum. Oncidium sphacelatum. Ornithoce
phalus inflexus. Polystachya!oliosa. 5. Ponera striata. Scaphyglottis behrii. Isochilus carnosiflorus. Maxillaria
tenuifolia. Nidema boothii. Trigonidium egertonianum. 6. Laelia rubescens 7. Epidendrum isthmi.
66 SELBYANA [Volume 17
r--I--' I}
j.---"
L
IJ
~ ~/
1\. l-/' II V
\./ ,,~
(
C.
V ~
15 ~ 1 [Q
~ ~...,. ,
l~l.f' ~'
111
FIOURES 8-13. Distribution patterns of Bromeliaceae. 8. Aechmea bracteata 9. Tillandsia fasciculata 10,
Tillandsia elongata var. subimbricata II. Tillandsia festucoides 12. Tillandsia f/exuosa 13. Tillandsia strepto
phylla.
uted over the Peninsula (similar to the orchid For the epiphytic ferns we have scant infor
distribution pattern of FIGURE 3), while the un mation for southeastern Quintana Roo and
known species is only found in the southern por therefore have not included the maps.
tion of Campeche and Quintana Roo in the tall
medium semi-evergreen forest. ConseYJIation ofH abitats and Epiphytes - Dur-
1996J OLMSTED & GOMEZ-JUAREZ: YUCATAN PENINSULA EPIPHYTES 67
--
I--J.--'" /~
/'
~-
'i V
i'\ .,/'.
( I \,. . / 'r, r;!. ~
/ , ~
5 ! 7f, ! 10
ffi. ~.4
{I'\- ((~7 [f IV
16
FIGURES 14-16. Distribution patterns ofCactaceae: 14. Selenicereus a'onkelaarii 15. Epiphyllum phyllanthus
16. Rhipsalis baccifera.
ing the last 20 years, we have witnessed a large epiphytes. The epiphytes usually do not survive
reduction of mature forest and an increase in fire. Natural recolonization would take many
disturbed vegetation and agricultural and cattle more years than the recuperation of the trees.
land on the Yucatan Peninsula. FIGURE 1 is an We have looked at many different ages of sec
indication of potential vegetation. By 1981 INE ondary vegetation (5-30 years) without finding
GI estimated that the state of Yucatan was totally epiphytes. In the Yucatan, the medium-statured
disturbed, and that the remaining non-disturbed semi-evergreen forest is still the most extensive
land was located in Quintana Roo and Campe and continues to provide a habitat for epiphytes
che. During the last 13 years much more forest
has become disturbed or permanently lost. In an
ongoing study about vegetation change in Mex TABLE 3. Change of vegetation cover 1975-1994 in
ico between the 1970's and the early 1990's, we southern Quintana Roo.
have begun an evaluation of the Peninsula, start
ing with the southern portion of Quintana Roo, 1975 1994
based on Landsat satellite images. Table 3 shows Hectares Hectares % change
the percent conversion that has occurred from Low inundated for-
mature semi-evergreen and inundated forest to est 381 566 280646 -26.4
agriculture and cattle ranching as well as other Medium semi-ever-
developments. green forest 520594 321 655 -38.2
Much secondary vegetation of the semi-ever Agriculture-cattle 12519 66472 430
Secondary vegeta-
green forest, usually as a result of burning and
tion 236307 405351 71
abandonment after milpa, is totally devoid of
