Friday, September 12, 2014

Dry forest articles (Biotropica 46(1); January 2014)

January 2014 Volume 46(1)

Three out of fourteen articles covered dry forest topics. Not bad coverage. Not surprisingly, given the pervasive human influence on tropical dry forests all of these studies focus on successional or disturbed sites.

Neves et al. examined how insect herbivory varies with successional stage and canopy height at Mata Seca State Park in Minas Gerais state, Brazil. This looks like an interesting site where a good body of research is being established. Their findings, overall:
We found that the richness of sap-sucking insect increased along the successional gradient at both spatial scales studied (tree and plot scales), but trends were mixed for the other tested variables. We also detected a vertical stratification in insect diversity which is affected by the interaction between guild and period of the rainy season. Such successional and vertical differences were also observed for leaf damage. Finally, we verified a decrease in morphospecies richness and abundance of both sap-sucking and chewing at the end of the rainy season.

Peguero and Espelta looked at tree regeneration triggers in the Miraflor-Moropotente plateau in northwestern Nicaragua. They described the area as "a partially protected landscape, i.e., silvo-pastoralism is allowed but some practices such as logging and fire are precluded" which has resulted in "a mosaic of wooded rangelands surrounded by secondary and remnant NDF [Neotropical Dry Forest] patches". They fed the fruits of three dry forest tree species (Acacia pennatula, Enterolobium cyclocarpum, and Guazuma ulmifolia) to calves (to determine feeding preference), and then subjected seeds of the same species to a rather fascinating system designed to simulate gut passage. 
To simulate the effects of gut passage on the seeds, we developed a three-step—(1) rumen; (2) abomasum-duodenum; (3) intestine—in vivo–in vitro standardized procedure... Fruits from five individuals of each species were hand-harvested and manually dehisced to obtain their seeds. Once in the laboratory, the seeds of each species from different individuals were pooled and put into sealed nylon bags in separate groups ... and then in the rumen of a cannulated cow. After 48 h of rumen suspension, the bags were placed in glass incubation bottles containing 2 l of 0.1 N HCl adjusted to pH 1.9 with 1 g/l of pepsin... ).
Finally, to reproduce the anaerobic intestinal environment, rectal feces samples from three different cows were collected in plastic bags saturated with CO2 and immediately placed in a water-bath with a buffer solution of salt minerals (NaCl, KCl, NaPO4, KPO4) at 39 °C. The feces were manually crumbled in order to re-suspend fiber-associated bacteria and the solution was filtered through a 250 μm mesh screen and completed with a buffer solution of salt minerals until reaching a dilution of 0.2 g fecal sample per ml of buffer (adapted from Bindelle et al2007). The bags with the intestinal bacterial inoculum were incubated 24 h more with constant rotation at 39 °C in anaerobic conditions. 
They then simulated fire by exposing the seeds to thermal shocks (60, 90, and 120 °C) and observed germination success. They found an additive effect of gut passage and 'fire' on seed germination. They ended with a lot of vague generalities about megafauna dispersal syndrome and the role of pasture trees as roosts for seed dispersers. Seeing someone else do it makes me acutely aware of how much of my dissertation must read.

The final one of these three articles deals with fruit and flower availability along a restoration gradient (which is, in fact, the very matter-of-fact, descriptive title of the article). This is another Brazilian study, this time semideciduous Atlantic forest in São Paulo state. All of these sites were former sugarcane plantations, and all were intentionally restored. The sites were 12, 23 and 55 years old, and were paired with a reference site in intact forest. Their findings:
Our data suggest that a wide range of plant growth forms provides resource complementarities to those of planted tree species. Different flower phenologies between trees and non-trees seem to be more evident in a forest with high non-tree species diversity. We recommend examples of ideal species for planting, both at the time of initial planting and post-planting during enrichment. These management actions can minimize shortage and periods of resource scarcity for frugivorous and nectarivorous fauna, increasing probability of restoring ecological processes and sustainability in restoration sites.
Two other articles earn 'honorable mention' in the dry forest category: Zeilhofer et al.'s jaguar habitat modelling paper (since it looks at cerrado which is, arguably, dry forest) and Domic et al.'s article about Polylepsis tomentella regeneration in semiarid Andean valleys. These are technically too dry and possibly too cold to meet most definitions of dry forest, but the underlying processes (and problems) related to regeneration would probably be familiar to dry forest species.
  • Zeilhofer, Peter, Cezar, Adelaine, Tôrres, Natália M., Jácomo, Anah T. de Almeida, and Silveira, Leandro. 2014. Jaguar Panthera onca Habitat Modeling in Landscapes Facing High Land-use Transformation Pressure—Findings from Mato Grosso, Brazil. Biotropica 46(1):98-105 DOI: 10.1111/btp.12074

So what is this thing, really?

Figured I'd try writing something for a more general audience.
Visit the tropical dry forest in the wet seasons and no one would fault you if you went home and told your friend about your trip to the rainforest. But come back a few months later and you'll wonder where all the green went. Many of the trees are now leafless; most of the rest still have some of their leaves, but they've lost a lot of them. The leaves that are left have a yellowed, bleached-out quality to them. And with their leaves gone, you notice how thorny a lot of the trees are. Not what you remember from your first visit, not at all.[read more]

Thursday, January 8, 2009

Recent literature (Journal of Tropical Ecology)

  • Kunz, Britta Kerstin, and Karl Eduard Linsenmair. 2008. The role of the olive baboon (Papio anubis, Cercopithecidae) as seed disperser in a savanna-forest mosaic of West Africa. Journal of Tropical Ecology 24(3):235-246 DOI:10.1017/S0266467408005014
  • Groen, Thomas A., Frank van Langevelde, Claudius A.D.M. van de Vijver, Navashni Govender and Herbert H.T. Prins. 2008. Soil clay content and fire frequency affect clustering in trees in South African savannas. Journal of Tropical Ecology 24(3):269-279 DOI:10.1017/S0266467408004872
  • Shannon, Graeme, Dave J. Druce, Bruce R. Page, Holger C. Eckhardt, Rina Grant and Rob Slotow. 2008. The utilization of large savanna trees by elephant in southern Kruger National Park. Journal of Tropical Ecology 24(3):281-289 DOI:10.1017/S0266467408004951
  • Zelikova, Tamara J., and Michael D. Breed. 2008. Effects of habitat disturbance on ant community composition and seed dispersal by ants in a tropical dry forest in Costa Rica. Journal of Tropical Ecology 24(3):309-316
  • Chidumayo, Emmanuel Ngulube. 2008. Growth of Bauhinia thonningii trees and saplings over a decade in a savanna in Zambia: interactions of climate, fire and source of regeneration. Journal of Tropical Ecology 24(4):407-415 DOI:10.1017/S0266467408005099
  • van Ingen, Laura T., Ricardo I. Campos and Alan N. Andersen. 2008. Ant community structure along an extended rain forest–savanna gradient in tropical Australia. Journal of Tropical Ecology 24(4):445-455 DOI:10.1017/S0266467408005166
  • Pavón, Numa P., and Irving de Luna Ramírez. 2008. Sex ratio, size distribution and nitrogen resorption in the dioecious tree species Bursera morelensis (Burseraceae). Journal of Tropical Ecology 24(4):463-466 DOI:10.1017/S026646740800518X
  • Garrido-Pérez, Edgardo I., Juan Manuel Dupuy, Rafael Durán-García, Mario Ucan-May, Stefan A. Schnitzer and Gerhard Gerold. 2008. Effects of lianas and Hurricane Wilma on tree damage in the Yucatan Peninsula, Mexico. Journal of Tropical Ecology 24(5):559-562 DOI:10.1017/S0266467408005221

Thursday, November 27, 2008

Recent literature

Recent papers related to tropical dry forests and savannas in the journal Biotropica:

Tabarelli, Marcelo, Ariadna V. Lopes, and Carlos A. Peres. 2008. Edge-effects Drive Tropical Forest Fragments Towards an Early-Successional System. Biotropica 40(6):657-661 doi:10.1111/j.1744-7429.2008.00454.x

Lebrija-Trejos, Edwin, Frans Bongers, Eduardo A. Pérez-García and Jorge A. Meave. 2008. Successional Change and Resilience of a Very Dry Tropical Deciduous Forest Following Shifting Agriculture. Biotropica 40(4):422-431 doi:10.1111/j.1744-7429.2008.00398.x

Poorter, Lourens and Lars Markesteijn. 2008. Seedling Traits Determine Drought Tolerance of Tropical Tree Species. Biotropica 40(3):321-331 doi:10.1111/j.1744-7429.2007.00380.x

Forrest Jessica L., Eric W. Sanderson, Robert Wallace, Teddy Marcelo Siles Lazzo, Luis Humberto Gómez Cerveró and Peter Coppolillo. 2008. Patterns of Land Cover Change in and Around Madidi National Park, Bolivia. Biotropica 40(3):285-294 doi:10.1111/j.1744-7429.2007.00382.x

Delsinne, Thibaut, Maurice Leponce, Laurence Theunis, Yves Braet, and Yves Roisin. 2008. Rainfall Influences Ant Sampling in Dry Forests. Biotropica 40(5):590-596 doi:10.1111/j.1744-7429.2008.00414.x

Kaminski, Lucas A. 2008. Polyphagy and Obligate Myrmecophily in the Butterfly Hallonympha paucipuncta (Lepidoptera: Riodinidae) in the Neotropical Cerrado Savanna. Biotropica 40(3):390-394 doi:10.1111/j.1744-7429.2007.00379.x

Santos, Evanira M. R., Elizabeth Franklinand William E. Magnusson. 2008. Cost-efficiency of Subsampling Protocols to Evaluate Oribatid-Mite Communities in an Amazonian Savanna. Biotropica 40(6):728-735 doi:10.1111/j.1744-7429.2008.00425.x

Vieira, Letícia, Júlio N. C. Louzada and Sacha Spector. 2008. Effects of Degradation and Replacement of Southern Brazilian Coastal Sandy Vegetation on the Dung Beetles (Coleoptera: Scarabaeidae). Biotropica 40(6):719-727 doi:10.1111/j.1744-7429.2008.00432.x

Wednesday, April 2, 2008

Recent literature

More recent literature on tropical dry forests and savannas

Martinia, Adriana M.Z., Renato A.F. Lima, Geraldo A.D.C. Franco and Ricardo R. Rodrigues. 2008. The need for full inventories of tree modes of disturbance to improve forest dynamics comprehension: An example from a semideciduous forest in Brazil. Forest Ecology and Management 255(5-6):1479-1488 doi:10.1016/j.foreco.2007.11.004

Ribeiroa, Natasha S., Herman H. Shugart and Robert Washington-Allen. 2008. The effects of fire and elephants on species composition and structure of the Niassa Reserve, northern Mozambique. Forest Ecology and Management 255(5-6):1626-1636 doi:10.1016/j.foreco.2007.11.033

Rista, Lucy, R. Uma Shaanker, E.J. Milner-Gullanda and Jaboury Ghazoul. 2008. Managing mistletoes: The value of local practices for a non-timber forest resource. Forest Ecology and Management 255(5-6):1684-1691 doi:10.1016/j.foreco.2007.11.030

Nouvellona, Yann, Daniel Epron, Antoine Kinana, Olivier Hamel, André Mabiala, Rémi D’Annunzio, Philippe Deleporte, Laurent Saint-André, Claire Marsden, Olivier Roupsard, Jean-Pierre Bouillet and Jean-Paul Laclau. 2008. Soil CO2 effluxes, soil carbon balance, and early tree growth following savannah afforestation in Congo: Comparison of two site preparation treatments. Forest Ecology and Management 255(5-6):1926-1936 doi:10.1016/j.foreco.2007.12.026

Monday, March 31, 2008


ReForLan (Restoration of Forest Landscapes for Biodiversity Conservation and Rural Development in the Drylands of Latin America) is a new project focusing on
the restoration of dryland forest landscapes for biodiversity conservation and rural development in Latin America.
The project has received three years of funding (2007-2010) and are working in seven sites around Latin America:
  1. Chiapas, Mexico
  2. Central Veracuz, Mexico
  3. Oaxaca, Mexico
  4. Central Valley, Central Chile
  5. Coastal range, Central Chile
  6. Northwestern Argentina
  7. Southwestern Argentina.
There's a write-up about the project in the March 2008 issue of Ecological Restoration.

Other definitions

Last year, Jeremy Bruno posted a description of dry forest at The Voltage Gate. (He has since moved to ScienceBlogs.) It's a pretty good overview - covers the main points, though I'm a tad uncertain about the assertion that erosion (post-deforestation) is higher than in rainforests.