Tree Islands of the Everglades (original) (raw)

Monitoring of Tree Island Condition in the Southern Everglades

Tree islands, a prominent feature in both the marl prairie and ridge and slough landscapes of the Everglades, are sensitive to large-scale restoration actions associated with the Comprehensive Everglades Restoration Plan (CERP) authorized by the Water Resources Development Act (WRDA) 2000 to restore the south Florida ecosystem. More specifically, changes in hydrologic regimes at both local and landscape scales are likely to affect the internal water economy of islands, which in turn will influence plant community structure and function. To strengthen our ability to assess the “performance” of tree island ecosystems and predict how these hydrologic alterations would translate into ecosystem response, an improved understating of reference conditions of vegetation structure and function, and their responses to major stressors is important. In this regard, a study of vegetation structure and composition in relation to associated physical and biological processes was initiated in 2005 wi...

Everglades tree island restoration: testing a simple tree planting technique patterned after a natural process

Tree islands in the Everglades are critical landscape features, but anthropogenic modification of the Everglades during the past century has led to the degradation and loss of many of the tree islands that originally dotted the Everglades landscape. Many of the tree islands have lost elevation and the majority of their woody species such that they are now covered with emergent plants such as sawgrass (Cladium jamaicense). A simple, cost-effective tree planting technique is needed for restoring degraded Everglades tree islands. We patterned our design after a natural Everglades process that creates floating islands, which promotes tree survival and growth in both flooded and dry conditions and may lead to the development of fixed islands. Commercial peat bags were tested as a means to provide the medium for the growth and establishment of potted tree saplings native to Everglades tree islands. Three tree species (Annona glabra, Ficus aurea, and Acer rubrum) and five treatments were evaluated. The results indicate that the preferred deployed peat-bag configuration should provide the greatest additional elevation to minimize inundation and be planted with a single Everglades tree island species sapling, with a single commercial tree fertilizer spike inserted for nutrients. Although most plants survived and many thrived for the two-year period of this study, determining whether the trees planted using this technique can become established will require longer-term studies and extensive field tests.

Survival and growth responses of eight Everglades tree species along an experimental hydrological gradient on two tree island types

Applied Vegetation Science, 2010

Questions: How are the early survival and growth of seedlings of Everglades tree species planted in an experimental setting on artificial tree islands affected by hydrology and substrate type? What are the implications of these responses for broader tree island restoration efforts?Location: Loxahatchee Impoundment Landscape Assessment (LILA), Boynton Beach, Florida, USA.Methods: An experiment was designed to test hydrological and substrate effects on seedling growth and survivorship. Two islands – a peat and a limestone-core island representing two major types found in the Everglades – were constructed in four macrocosms. A mixture of eight tree species was planted on each island in March of 2006 and 2007. Survival and height growth of seedlings planted in 2006 were assessed periodically during the next two and a half years.Results: Survival and growth improved with increasing elevation on both tree island substrate types. Seedlings' survival and growth responses along a moisture gradient matched species distributions along natural hydrological gradients in the Everglades. The effect of substrate on seedling performance showed higher survival of most species on the limestone tree islands, and faster growth on their peat-based counterparts.Conclusions: The present results could have profound implications for restoration of forests on existing landforms and artificial creation of tree islands. Knowledge of species tolerance to flooding and responses to different edaphic conditions present in wetlands is important in selecting suitable species to plant on restored tree islands