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M671 Pithecellobium unguis-cati - Opuntia spp. - Agave spp. Scrub Macrogroup
Type Concept Sentence: This dry scrub macrogroup, found in the Florida Keys and most of the Caribbean islands, varies widely in floristic composition across its distribution but has a broadly similar set of ecological factors, including highly seasonal precipitation and limiting substrate conditions, such as ultramafic soils, exposed limestone, dogtooth limestone, or coastal rock pavements, limestone terraces, and boulderfields exposed to wind and salt spray. The vegetation is typically open, with a low-statured canopy formed by small trees and shrubs, where often cacti are dominant or codominant. Floristic diversity is relatively low and endemism levels are very high.
Common (Translated Scientific) Name: Catclaw Blackbead - Prickly-pear species - Agave species Scrub Macrogroup
Colloquial Name: Caribbean Dry Scrub
Hierarchy Level: Macrogroup
Type Concept: This macrogroup encompass tropical and subtropical dry scrub distributed in the Florida Keys and most of the Caribbean islands. The physiognomy of the vegetation types included is varied: from an open, primarily herbaceous community with scattered shrubs and columnar and tree-shaped cacti, to a mixed evergreen, drought-deciduous scrub (stunted trees, shrubs and low palms) with succulents, which can be dense and varying in height from 0.4 to 4 m. Stands of serpentine scrubs that alternate with small grassy clearings also occur, as well as sand savannas. Common plant growth forms include evergreen sclerophyllous and microphyllous shrubs, small or arborescent cacti, plants in rosettes (such as agaves and terrestrial bromeliads), semi-deciduous shrubs, and emergent palms. The ecology is characterized by a dry season of 2-6 months and occurs on limiting substrate conditions related to the presence of ultramafic soils, exposed limestone, dogtooth limestone, or rocky areas of Key Largo limestone with little soil or leaf litter. Most commonly these environmental characteristics are present in coastal areas; however, inland communities can occur growing on ferrallitic soils, which are derived from serpentine in isolated locations in the lowlands. Habitat diversity in this edaphoxerophylous system is spatially very heterogeneous and patchy. Given that this type develops under limiting environmental factors, variation in the dry season period, topography, and substrate determines the specific characteristics of the vegetation communities in this macrogroup since all of these factors have great importance as determinants of variation in water availability and physiological adaptations.
Diagnostic Characteristics: Stands are characterized by an overstory of scattered shrubs (Cordia spp. Erithalis fruticosa), stunted trees (Eugenia, Bursera, Thouinia, Coccoloba spp.) or short-statured palms (Coccothrinax spp.), and herbaceous communities with grasses or sedges codominated by Agave spp. and small or columnar cacti (Melocactus, Opuntia, Harrisia, Pilosocereus). The canopy layer varies from very open to closed depending on the site conditions.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: No Data Available
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: The physiognomy of the vegetation types included is varied: from an open, primarily herbaceous community with scattered shrubs in the Florida Keys, to a mixed evergreen, drought-deciduous scrub of stunted trees, shrubs, low palms, and succulents, which can be dense and varying in height from 0.4 to 4 m with scattered emergent trees or palms; the latter physiognomy is more common of the communities in the Caribbean islands. Stands of serpentine scrubs that alternate with small grassy clearings also occur in Cuba and Puerto Rico. The macrogroup includes edaphic savannas growing on silica sands that support short grass and sedge savanna with palms and sometimes with pines (WWF and IUCN 1997). In the scrub community types, common plant growth forms include evergreen sclerophyllous and microphyllous shrubs, small or arborescent cacti, plants in rosettes (such as agaves and terrestrial bromeliads), semi-deciduous shrubs, and emergent palms. The scrub physiognomy is determined by a combination of low rainfall, which may be less than 700 mm per year (WWF and IUCN 1997) and the harsh conditions imposed by the substrate.
Floristics: In the Florida Keys the cactus barren community pertaining to this macrogroup consists of a wide variety of herbaceous and succulent species which characteristically includes cacti, agaves, stunted trees, and several rare herbs. These frequently occur with grasses and sedges, such as Leptochloa dubia, Paspalidium chapmanii, and Cyperus elegans (Avery 1982, as cited in FNAI 2010a). Spiny species, particularly the rare Opuntia triacantha, are characteristic but their abundance is variable. Other spiny species include Agave decipiens, Acanthocereus tetragonus, and Opuntia stricta. Scattered clumps of stunted trees may be present, including Bursera simaruba, Conocarpus erectus, Eugenia foetida, and Pithecellobium unguis-cati (Avery 1982, as cited in FNAI 2010a). Diagnostic species vary across the Caribbean islands; the Cuban scrub on limestone substrate is dominated by the shrubs Auerodendron cubense, Coccothrinax munizii, Cordia leucosebestena, Eugenia cowellii, Jacquinia berteroi, Picrodendron macrocarpum, Polygala guantanamana, Randia spinifex, and cacti and succulents Agave albescens, Consolea macracantha, Dendrocereus nudiflorus, Harrisia fernowii, Melocactus acunae, and Pilosocereus brooksianus (Huggins et al. 2007), while this type in Puerto Rico features endemic Harrisia portoricensis, and shrubs Croton discolor, Croton betulinus, Erithalis fruticosa, Plumeria obtusa, and Reynosia uncinata (Rojas-Sandoval and Melendez-Ackerman 2012b, Medina et al. 2014).
In the Lesser Antilles typical species of the mixed cactus scrub on limestone pavement include Agave karatto, Capparis cynophallophora, Capparis indica, Clerodendrum aculeatum, Haematoxylon campechianum, Leucaena leucocephala, Pilosocereus royenii, Pisonia aculeata, Pisonia subcordata, and Pithecellobium unguis-cati (Areces-Mallea et al. 1999). In Bahamas, when the limestone pavement community occurs right above the water table and there is more moisture available, characteristic species include Sideroxylon americanum (= Bumelia americana), Bursera simaruba, Cephalocereus sp., Cladium mariscus ssp. jamaicense, Coccoloba northropiae, Coccoloba tenuifolia, Guettarda scabra, Manilkara jaimiqui ssp. emarginata (= Manilkara bahamensis), Pithecellobium bahamense, Psidium longipes, Randia aculeata, Stigmaphyllon sagraeanum, and Tabebuia bahamensis (Areces-Mallea et al. 1999). On serpentine derived soils present in Puerto Rico and Cuba, characteristic species include Comocladia dodonaea, Croton lucidus, Pictetia aculeata, Pilosocereus royenii, Plumeria alba, Thouinia striata var. portoricensis and evergreen trees Acrosynanthus minor, Annona bullata, Antirhea abbreviata, Antirhea orbicularis, Byrsonima bucheri, Exostema purpureum, Hemithrinax savannarum, Jacquinia shaferi, Myrtus cabanesensis, Neobracea valenzuelana, Phyllanthus comosus, Phyllanthus orbicularis, Rondeletia camarioca, Spirotecoma apiculata, and Tabebuia linearis.
In the Lesser Antilles typical species of the mixed cactus scrub on limestone pavement include Agave karatto, Capparis cynophallophora, Capparis indica, Clerodendrum aculeatum, Haematoxylon campechianum, Leucaena leucocephala, Pilosocereus royenii, Pisonia aculeata, Pisonia subcordata, and Pithecellobium unguis-cati (Areces-Mallea et al. 1999). In Bahamas, when the limestone pavement community occurs right above the water table and there is more moisture available, characteristic species include Sideroxylon americanum (= Bumelia americana), Bursera simaruba, Cephalocereus sp., Cladium mariscus ssp. jamaicense, Coccoloba northropiae, Coccoloba tenuifolia, Guettarda scabra, Manilkara jaimiqui ssp. emarginata (= Manilkara bahamensis), Pithecellobium bahamense, Psidium longipes, Randia aculeata, Stigmaphyllon sagraeanum, and Tabebuia bahamensis (Areces-Mallea et al. 1999). On serpentine derived soils present in Puerto Rico and Cuba, characteristic species include Comocladia dodonaea, Croton lucidus, Pictetia aculeata, Pilosocereus royenii, Plumeria alba, Thouinia striata var. portoricensis and evergreen trees Acrosynanthus minor, Annona bullata, Antirhea abbreviata, Antirhea orbicularis, Byrsonima bucheri, Exostema purpureum, Hemithrinax savannarum, Jacquinia shaferi, Myrtus cabanesensis, Neobracea valenzuelana, Phyllanthus comosus, Phyllanthus orbicularis, Rondeletia camarioca, Spirotecoma apiculata, and Tabebuia linearis.
Dynamics: The natural process giving rise to cactus barrens in the Florida Keys is not known, but since they occur on sites where the thin layer of organic soil over limestone bedrock is missing, they may have formed by soil erosion following destruction of the plant cover by fire, storm, or artificial clearing. The edaphic shortgrass savannas have been characterized in Cuba as a natural community (Schizachyrium tenerum, Leptocoryphium lanatum, Byrsonima) by Fiala and Herrera (1988) but other studies (Borhidi 1988) state that the original vegetation of these soil types is a thorny scrub/woodland consisting of endemic palms and trees which has been converted long ago to open palm grasslands, and used intensively as pastures. Thus, ~Caribbean Moist Shortgrass Savanna Group (G465)$$, included in this macrogroup, should be considered a seral stage resulting from the past intense disturbance of the thorny scrub referred to by Borhidi (1988).
Environmental Description: Climate: At sea level, temperatures in February, which is often the coolest and driest month, rarely fall to 12°C. Rainy seasons are usually warmer, but temperature maxima rarely reach 33°C. Overall averages at sea level are mostly in the range 25-27°C. Annual precipitation ranges from 600 to 1500 mm for the distribution range of this macrogroup and the dry season is usually limited to one period that can last for 2-6 months, or divided into two periods together lasting up to 8 months. The main dry period is usually between January and April; there may be a second dry period in more southerly latitudes in July to September.
Soil/substrate/hydrology: The limestone substrate has low water-retention capacity, and rainfall leaches easily after accumulating in cracks and crevices of variable depth. The underlying calcareous rock is prone to erosion in the presence of water acidified with CO2 from the atmosphere or contributed by root respiration and decomposition of organic matter in the litter layer (Lugo et al. 2001 cited in Medina et al. 2014). The major nutrient sources in these areas are probably cations adsorbed by the clay accumulated in cracks and crevices, and deposited on the bottom of the depressions (Medina et al. 2014). The macrogroup includes edaphic savannas growing on silica sands and in seasonal conditions that result in actual drought during periods of low rainfall and physiological drought due to impeded drainage and waterlogging during periods of high rainfall. These savannas are level and usually have topsoils of silica sands with impervious subsoil horizons. They occur in Cuba, Jamaica, Puerto Rico and Trinidad and are renowned for their local floristic diversity in contrast to savannas derived from removal of the woodlands and periodical fire and grazing. (WWF and IUCN 1997).
Soil/substrate/hydrology: The limestone substrate has low water-retention capacity, and rainfall leaches easily after accumulating in cracks and crevices of variable depth. The underlying calcareous rock is prone to erosion in the presence of water acidified with CO2 from the atmosphere or contributed by root respiration and decomposition of organic matter in the litter layer (Lugo et al. 2001 cited in Medina et al. 2014). The major nutrient sources in these areas are probably cations adsorbed by the clay accumulated in cracks and crevices, and deposited on the bottom of the depressions (Medina et al. 2014). The macrogroup includes edaphic savannas growing on silica sands and in seasonal conditions that result in actual drought during periods of low rainfall and physiological drought due to impeded drainage and waterlogging during periods of high rainfall. These savannas are level and usually have topsoils of silica sands with impervious subsoil horizons. They occur in Cuba, Jamaica, Puerto Rico and Trinidad and are renowned for their local floristic diversity in contrast to savannas derived from removal of the woodlands and periodical fire and grazing. (WWF and IUCN 1997).
Geographic Range: This macrogroup is distributed in the Florida Keys and most of the islands of the Greater and Lesser Antilles.
Nations: BS,CU,DO,HT,JM,PR,TT,US,VI,XC,XD
States/Provinces: FL
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.884847
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 2 Shrub & Herb Vegetation Class | C02 | 2 |
| Subclass | 2.A Tropical Grassland, Savanna & Shrubland Subclass | S01 | 2.A |
| Formation | 2.A.1 Tropical Lowland Grassland, Savanna & Shrubland Formation | F019 | 2.A.1 |
| Division | 2.A.1.Ea Caribbean-Mesoamerican Lowland Grassland, Savanna & Shrubland Division | D094 | 2.A.1.Ea |
| Macrogroup | 2.A.1.Ea.1 Catclaw Blackbead - Prickly-pear species - Agave species Scrub Macrogroup | M671 | 2.A.1.Ea.1 |
| Group | 2.A.1.Ea.1.a Prickly-pear species - Chapman''s Bristlegrass Caribbean Coastal Cactus Scrub Group | G485 | 2.A.1.Ea.1.a |
| Group | 2.A.1.Ea.1.b Caribbean Karstic Dry Scrub Group | G479 | 2.A.1.Ea.1.b |
| Group | 2.A.1.Ea.1.c Caribbean Serpentine Dry Scrub Group | G463 | 2.A.1.Ea.1.c |
| Group | 2.A.1.Ea.1.d Bluestem species - Grama species - Rabo-de-Gato Caribbean Moist Shortgrass Savanna Group | G465 | 2.A.1.Ea.1.d |
Concept Lineage: M288 is redundant with M671 (DFL 5-17-13); M295 concept is covered by M671 (CJ 5-14-13); M297 replaced by M671 (DFL 3-26-13); M670 - Antillean Mixed Evergreen & Deciduous Shrubland concept covered by M671 (CJ 5-14-13)
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: No Data Available
- Areces-Mallea, A. E., A. S. Weakley, X. Li, R. G. Sayre, J. D. Parrish, C. V. Tipton, and T. Boucher. 1999. A guide to Caribbean vegetation types: Preliminary classification system and descriptions. The Nature Conservancy, Arlington, VA. 166 pp.
- Borhidi, A. 1988. Vegetation dynamics of the savannization process on Cuba. Vegetatio 77:177-183.
- FNAI [Florida Natural Areas Inventory]. 2010a. Guide to the natural communities of Florida: 2010 edition. Florida Natural Areas Inventory, Tallahassee, FL. 228 pp. [https://fnai.org/naturalcommguide.cfm]
- Faber-Langendoen, D., J. Drake, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2019a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]
- Fiala, K., and R. Herrera. 1988. Living and dead belowground biomass and its distribution in some savanna communities in Cuba. Folia Geobotanica et Phytotaxonomica 23(2):113-224.
- Huggins, A. E., S. Keel, P. Kramer, F. Núñez, S. Schill, R. Jeo, A. Chatwin, K. Thurlow, M. McPherson, M. Libby, R. Tingey, M. Palmer, and R. Seybert. 2007. Biodiversity conservation assessment of the insular Caribbean using the Caribbean Decision Support System, Technical Report, The Nature Conservancy.
- Medina, E., E. H. Helmer, E. Meléndez-Ackerman, and H. Marcano-Vega. 2014. Natural vegetation groups and canopy chemical markers in a dry subtropical forest on calcareous substrate: The vegetation of Mona Island, Puerto Rico. Caribbean Naturalist 13:1-15.
- Rojas-Sandoval, J., and E. Melendez-Ackerman. 2012b. Factors affecting establishment success of the endangered Caribbean cactus Harrisia portoricensis (Cactaceae). International Journal of Tropical Biology 60 (2):867-879.
- WWF and IUCN [World Wildlife Fund and The World Conservation Union]. 1997. Centres of Plant Diversity. A guide and strategy for their conservation. Volume 3. IUCN Publications Unit. Cambridge, U.K.