Mangrove view near Telchac Pueblo, Yucatan, photo by Johan Siebols
The aerial view of Hotel Reef shows a complex of buildings separated by sand from the Gulf of Mexico to the north by about 20 yards. South of the complex, about 20 yards from the parking lot, there's a shallow lagoon that fills and empties with saltwater according to the tides. Many such lagoons parallel the beach all along the Yucatan coast, and they are home to an enormous variety of birds, crabs, fish and other organisms.
When the tide is low extensive mudflats are exposed, attracting several small wading bird species such as Semipalmated Plovers and Semipalmated Sandpipers. These birds stalk across the shiny mud busily probing with their beaks, occasionally extracting writhing worms with their needle-like bills. They must seldom catch anything because often I've seen that when suddenly a worm does appear in their bills the birds look surprised, flit their wings and jump backwards. At high tide White Pelicans, Neotropical Cormorants and others float on the water's surface, the pelicans reminding me of stately little white-sailed sailboats, the cormorants of dark, low submarines cruising at the surface.
At high tide in most places the lagoons' waters extend right up to dark green, shrubby walls usually eight to fifteen feet high. These shrubby walls are formed by woody shrubs known as mangroves. Mangrove wetlands such as these are among the most biologically rich and therefore ecologically important ecosystems on Earth.
In this part of the world we often speak of four different mangrove species. Next to Hotel Reef three of the species are very common, and I suspect the fourth is nearby.
In the lagoon next to the hotel two mangrove species predominate: Red Mangrove and Black Mangrove. From a distance they're very similar -- both with opposite, simple, shiny, evergreen, leathery leaves on much- branching, woody limbs. However, their flowers and fruits are completely different, and they belong to unrelated families.
Red Mangroves are RHIZOPHORA MANGLE, belonging to the Mangrove Family, the Rhizophoraceae. This species is easy to identify because the bottom part of its trunk branches profusely into numerous leafless "stilt roots" or "prop roots" that arch broadly in the air before entering water. Stilt roots provide the plant with stability in the loose mud and gather oxygen for underground parts. The airborne roots of one Red Mangrove intertwine with the next forming impenetrable thickets. Shellfish colonize the roots and fish and many other kinds of creature hide among them. The roots gather mud and build up the land. Red Mangrove is one of the most ecologically important woody plants I know.
Red Mangrove's fruits germinate while still on its branches. As the image at
the right shows, a green, sharp-pointed root emerges from the fruit's base forming
something like a dagger pointing earthward. When the fruit falls, the dagger-root stabs
into the mud, automatically planting the new tree.
The other super-abundant mangrove next to the hotel is Black Mangrove, AVICENNIA NITIDA, of the Verbena Family, the Verbenaceae. It's easy to identify because from its widely spreading, belowground roots hundreds of slender, gray-brown, pencil-like items emerge vertically from the mud to about a foot high. These are called pneumatophores and they collect oxygen for the submerged roots. Black Mangrove grows a little higher above the low-tide mark than Red Mangrove, so typically you notice their pneumatophores emerging from mud, not water. I often spot tiny crabs rushing through the Black Mangrove's pneumatophore jungle as I pass by.
Even higher above the low-tide mark, often on fairly dry ground at the edge of causeways crossing lagoons, there appears Buttonwood, CONOCARPUS ERECTA, of the Combretum Family, the Combretaceae. Unlike the three other species considered to be mangroves, Buttonwood has alternate leaves. At this time of year its fruits are clustered in spherical, brown, pea-sized, conelike heads.
The fourth species I expect to find soon is the White Mangrove, LAGUNCULARIA RACEMOSA, also of the Combretum Family.
You can see pictures of the Red Mango's stilt roots, the Black Mangrove's pneumatophores, and the other species as well, on our own Mangrove Page.