tag:blogger.com,1999:blog-54611402510046408462024-02-08T10:13:41.979-06:00Tropical Dry ForestIanhttp://www.blogger.com/profile/01010178962574928062noreply@blogger.comBlogger13125tag:blogger.com,1999:blog-5461140251004640846.post-12126502633300461722014-09-12T09:01:00.003-05:002014-09-12T09:01:44.731-05:00Dry forest articles (Biotropica 46(1); January 2014)January 2014 Volume 46(1)<br />
<br />
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.<br />
<br />
Neves <i>et al</i>. examined how insect herbivory varies with successional stage and canopy height at <a href="http://www.protectedplanet.net/sites/Mata_Seca_State_Park">Mata Seca State Park</a> in Minas Gerais state, Brazil. This looks like an interesting site where a good body of research is being established. Their findings, overall:<br />
<blockquote class="tr_bq">
<span style="background-color: white; font-family: Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 12px; line-height: 18px;">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.</span></blockquote>
<br />
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>i.e</i>., 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 (<i>Acacia pennatula, Enterolobium cyclocarpum</i>, and <i>Guazuma ulmifolia</i>) to calves (to determine feeding preference), and then subjected seeds of the same species to a rather fascinating system designed to simulate gut passage. <blockquote class="tr_bq">
<span style="background-color: white; font-family: Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 12px; line-height: 18px;">To simulate the effects of gut passage on the seeds, we developed a three-step—(1) rumen; (2) abomasum-duodenum; (3) intestine—</span><em style="background: rgb(255, 255, 255); border: 0px; font-family: Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 12px; line-height: 18px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;">in vivo–in vitro</em><span style="background-color: white; font-family: Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 12px; line-height: 18px;"> standardized procedure..</span><span style="background-color: white; font-family: Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 12px; line-height: 18px;">. 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 </span><em style="background: rgb(255, 255, 255); border: 0px; font-family: Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 12px; line-height: 18px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;">N</em><span style="background-color: white; font-family: Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 12px; line-height: 18px;"> HCl adjusted to pH 1.9 with 1 g/l of pepsin... ).</span></blockquote>
<div>
<blockquote class="tr_bq">
<span style="background-color: white; font-family: Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 12px; line-height: 18px;">Finally, to reproduce the anaerobic intestinal environment, rectal feces samples from three different cows were collected in plastic bags saturated with CO</span><sub style="background: rgb(255, 255, 255); border: 0px; font-family: Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 0.8em; line-height: 0.7em; margin: 0px; outline: 0px; padding: 0px; white-space: nowrap;">2</sub><span style="background-color: white; font-family: Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 12px; line-height: 18px;"> and immediately placed in a water-bath with a buffer solution of salt minerals (NaCl, KCl, NaPO</span><sub style="background: rgb(255, 255, 255); border: 0px; font-family: Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 0.8em; line-height: 0.7em; margin: 0px; outline: 0px; padding: 0px; white-space: nowrap;">4</sub><span style="background-color: white; font-family: Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 12px; line-height: 18px;">, KPO</span><sub style="background: rgb(255, 255, 255); border: 0px; font-family: Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 0.8em; line-height: 0.7em; margin: 0px; outline: 0px; padding: 0px; white-space: nowrap;">4</sub><span style="background-color: white; font-family: Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 12px; line-height: 18px;">) 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 </span><em style="background: rgb(255, 255, 255); border: 0px; font-family: Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 12px; line-height: 18px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;">et al</em><span style="background-color: white; font-family: Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 12px; line-height: 18px;">. </span><a class="referenceLink" href="http://onlinelibrary.wiley.com/doi/10.1111/btp.12076/full#btp12076-bib-0004" rel="references:#btp12076-bib-0004" shape="rect" style="background: rgb(255, 255, 255); border: 0px; color: #007e8a; font-family: Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 12px; line-height: 18px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;" title="Link to bibliographic citation">2007</a><span style="background-color: white; font-family: Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 12px; line-height: 18px;">). The bags with the intestinal bacterial inoculum were incubated 24 h more with constant rotation at 39 °C in anaerobic conditions. </span></blockquote>
<div>
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.</div>
<div>
<br /></div>
<div>
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:</div>
<blockquote class="tr_bq">
<span style="font-family: Arial, Helvetica, sans-serif; font-size: x-small;">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.</span></blockquote>
<div>
<ul>
<li>Neves, Federico S., Silva, Jhonathan O., Espírito-Santo, Mário M., Fernandes, and Geraldo W. 2014. <a href="http://onlinelibrary.wiley.com/doi/10.1111/btp.12068/abstract">Insect Herbivores and Leaf Damage along Successional and Vertical Gradients in a Tropical Dry Forest</a>. <i>Biotropica </i><b>46(1)</b>:14-24 DOI: 10.1111/btp.12068</li>
<li>Peguero, Guille, and Espelta, Josep M. 2014. <a href="http://onlinelibrary.wiley.com/doi/10.1111/btp.12076/abstract">Endozoochory and Fire as Germination Triggers in Neotropical Dry Forests: an Experimental Test</a>. <i>Biotropica </i><b>46(1)</b>:83-89 DOI: 10.1111/btp.12076</li>
<li>Garcia, Letícia C., Hobbs, Richard J., Mäes dos Santos, Flavio A., Rodrigues, and Ricardo R. 2014. <a href="http://onlinelibrary.wiley.com/doi/10.1111/btp.12080/abstract">Flower and Fruit Availability along a Forest Restoration Gradien</a>t. <i>Biotropica </i><b>46(1)</b>:114-123 DOI: 10.1111/btp.12080</li>
</ul>
<div>
Two other articles earn 'honorable mention' in the dry forest category: Zeilhofer <i>et al</i>.'s jaguar habitat modelling paper (since it looks at cerrado which is, arguably, dry forest) and Domic <i>et al</i>.'s article about <i>Polylepsis tomentella </i>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.</div>
<div>
<ul>
<li>Zeilhofer, Peter, Cezar, Adelaine, Tôrres, Natália M., Jácomo, Anah T. de Almeida, and Silveira, Leandro. 2014. Jaguar <i>Panthera onca</i> Habitat Modeling in Landscapes Facing High Land-use Transformation Pressure—Findings from Mato Grosso, Brazil. <i>Biotropica </i><b>46(1)</b>:98-105 DOI: 10.1111/btp.12074</li>
</ul>
</div>
<div>
<ul>
<li>Domic, Alejandra I., Camilo, Gerardo R., and Capriles, José M. 2014. <a href="http://onlinelibrary.wiley.com/doi/10.1111/btp.12075/abstract">Small-scale Farming and Grazing Reduce Regeneration of <i>Polylepis tomentella</i> (Rosaceae) in the Semiarid Andes of Bolivia</a>. <i>Biotropica </i><b>46(1)</b>:106-113 DOI: 10.1111/btp.12075</li>
</ul>
</div>
</div>
</div>
Ianhttp://www.blogger.com/profile/01010178962574928062noreply@blogger.com0tag:blogger.com,1999:blog-5461140251004640846.post-19767766334409404922014-09-12T07:08:00.002-05:002014-09-12T07:08:36.203-05:00So what is this thing, really?Figured I'd try writing something for a more general audience.<blockquote class="tr_bq">
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.[<a href="http://iramjohn.hubpages.com/hub/Tropical-dry-forest">read more</a>]</blockquote>
Ianhttp://www.blogger.com/profile/01010178962574928062noreply@blogger.com0tag:blogger.com,1999:blog-5461140251004640846.post-26870024674139214282009-01-08T03:07:00.004-06:002009-01-08T03:25:34.150-06:00Recent literature (Journal of Tropical Ecology)<ul><li>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. <span style="font-style: italic;">Journal of Tropical Ecology</span> <span style="font-weight: bold;">24</span>(3):235-246 DOI:<a href="http://dx.doi.org/10.1017/S0266467408005014">10.1017/S0266467408005014</a><br /></li><li>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. <span style="font-style: italic;">Journal of Tropical Ecology</span> <span style="font-weight: bold;">24</span>(3):269-279 DOI:<a href="http://dx.doi.org/10.1017/S0266467408004872">10.1017/S0266467408004872</a><br /></li><li>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. <span style="font-style: italic;">Journal of Tropical Ecology</span> <span style="font-weight: bold;">24</span>(3):281-289 DOI:<a href="http://dx.doi.org/10.1017/S0266467408004951">10.1017/S0266467408004951</a></li><li>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. <span style="font-style: italic;">Journal of Tropical Ecology</span> <span style="font-weight: bold;">24</span>(3):309-316</li><li>Chidumayo, Emmanuel Ngulube. 2008. Growth of <span style="font-style: italic;">Bauhinia thonningii</span> trees and saplings over a decade in a savanna in Zambia: interactions of climate, fire and source of regeneration. <span style="font-style: italic;">Journal of Tropical Ecology</span> <span style="font-weight: bold;">24</span>(4):407-415 DOI:<a href="http://dx.doi.org/10.1017/S0266467408005099">10.1017/S0266467408005099</a><br /></li><li>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. <span style="font-style: italic;">Journal of Tropical Ecology</span> <span style="font-weight: bold;">24</span>(4):445-455 DOI:<a href="http://dx.doi.org/10.1017/S0266467408005166">10.1017/S0266467408005166</a><br /></li><li>Pavón, Numa P., and Irving de Luna Ramírez. 2008. Sex ratio, size distribution and nitrogen resorption in the dioecious tree species<span style="font-style: italic;"> Bursera morelensis</span> (Burseraceae). <span style="font-style: italic;">Journal of Tropical Ecology</span> <span style="font-weight: bold;">24</span>(4):463-466 DOI:<a href="http://dx.doi.org/10.1017/S026646740800518X">10.1017/S026646740800518X</a><br /></li><li>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. <span style="font-style: italic;">Journal of Tropical Ecology</span> <span style="font-weight: bold;">24</span>(5):559-562 DOI:<a href="http://dx.doi.org/10.1017/S0266467408005221">10.1017/S0266467408005221</a></li></ul>Ianhttp://www.blogger.com/profile/01010178962574928062noreply@blogger.com1tag:blogger.com,1999:blog-5461140251004640846.post-62264777492549865252008-11-27T23:14:00.003-06:002008-11-28T00:09:05.301-06:00Recent literatureRecent papers related to tropical dry forests and savannas in the journal <span style="font-style: italic;">Biotropica</span>:<br /><br />Tabarelli, Marcelo, Ariadna V. Lopes, and Carlos A. Peres. 2008. Edge-effects Drive Tropical Forest Fragments Towards an Early-Successional System. <span style="font-style: italic;">Biotropica</span> <span style="font-weight: bold;">40(6):</span>657-661 <a href="http://dx.doi.org/10.1111/j.1744-7429.2008.00454.x">doi:<span class="doi">10.1111/j.1744-7429.2008.00454.x</span></a><br /><br /><a href="http://www.fem.wur.nl/UK/Staff/PhD+students/trejos/default.htm">Lebrija-Trejos, Edwin</a>, 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. <span style="font-style: italic;">Biotropica</span> <span style="font-weight: bold;">40(4)</span>:422-431 <a href="http://dx.doi.org/10.1111/j.1744-7429.2008.00398.x">doi:10.1111/j.1744-7429.2008.00398.x</a><br /><br />Poorter, Lourens and Lars Markesteijn. 2008. Seedling Traits Determine Drought Tolerance of Tropical Tree Species. <span style="font-style: italic;">Biotropica</span> <span style="font-weight: bold;">40(3)</span>:321-331 <a href="http://dx.doi.org/10.1111/j.1744-7429.2007.00380.x">doi:10.1111/j.1744-7429.2007.00380.x</a><br /><br />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. <span style="font-style: italic;">Biotropica </span><span style="font-weight: bold;">40(3)</span>:285-294 <a href="http://dx.doi.org/10.1111/j.1744-7429.2007.00382.x">doi:10.1111/j.1744-7429.2007.00382.x</a><br /><br />Delsinne, Thibaut, Maurice Leponce, Laurence Theunis, Yves Braet, and Yves Roisin. 2008. Rainfall Influences Ant Sampling in Dry Forests. <span style="font-style: italic;">Biotropica </span><span style="font-weight: bold;">40(5)</span>:590-596 <a href="http://dx.doi.org/10.1111/j.1744-7429.2008.00414.x">doi:<span class="doi">10.1111/j.1744-7429.2008.00414.x</span></a><br /><br />Kaminski, Lucas A. 2008. Polyphagy and Obligate Myrmecophily in the Butterfly Hallonympha paucipuncta (Lepidoptera: Riodinidae) in the Neotropical Cerrado Savanna. <span style="font-style: italic;">Biotropica</span> <span style="font-weight: bold;">40(3)</span>:390-394 <a href="http://dx.doi.org/10.1111/j.1744-7429.2007.00379.x">doi:10.1111/j.1744-7429.2007.00379.x</a><br /><br />Santos, Evanira M. R., Elizabeth Franklinand William E. Magnusson. 2008. Cost-efficiency of Subsampling Protocols to Evaluate Oribatid-Mite Communities in an Amazonian Savanna. <span style="font-style: italic;">Biotropica </span><span style="font-weight: bold;">40(6)</span>:728-735 <a href="http://dx.doi.org/10.1111/j.1744-7429.2008.00425.x">doi:<span class="doi">10.1111/j.1744-7429.2008.00425.x</span></a><br /><br />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). <span style="font-style: italic;">Biotropica </span><span style="font-weight: bold;">40(6)</span>:719-727 <a href="http://dx.doi.org/10.1111/j.1744-7429.2008.00432.x">doi:<span class="doi">10.1111/j.1744-7429.2008.00432.x</span></a>Ianhttp://www.blogger.com/profile/01010178962574928062noreply@blogger.com0tag:blogger.com,1999:blog-5461140251004640846.post-88203618646657304442008-04-02T13:22:00.002-05:002008-04-02T13:31:05.595-05:00Recent literatureMore recent literature on tropical dry forests and savannas<br /><br />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. <span style="font-style: italic;">Forest Ecology and Management</span> <span style="font-weight: bold;">255(5-6)</span>:1479-1488 <a href="http://dx.doi.org/10.1016/j.foreco.2007.11.004" target="doilink" onclick="var doiWin; doiWin=window.open('http://dx.doi.org/10.1016/j.foreco.2007.11.004','doilink','scrollbars=yes,resizable=yes,directories=yes,toolbar=yes,menubar=yes,status=yes'); doiWin.focus()">doi:10.1016/j.foreco.2007.11.004</a><br /><br />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. <span style="font-style: italic;">Forest Ecology and Management</span> <span style="font-weight: bold;">255(5-6)</span>:1626-1636 <a href="http://dx.doi.org/10.1016/j.foreco.2007.11.033" target="doilink" onclick="var doiWin; doiWin=window.open('http://dx.doi.org/10.1016/j.foreco.2007.11.033','doilink','scrollbars=yes,resizable=yes,directories=yes,toolbar=yes,menubar=yes,status=yes'); doiWin.focus()">doi:10.1016/j.foreco.2007.11.033</a><br /><br />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. <span style="font-style: italic;">Forest Ecology and Management</span> <span style="font-weight: bold;">255(5-6)</span>:1684-1691 <a href="http://dx.doi.org/10.1016/j.foreco.2007.11.030" target="doilink" onclick="var doiWin; doiWin=window.open('http://dx.doi.org/10.1016/j.foreco.2007.11.030','doilink','scrollbars=yes,resizable=yes,directories=yes,toolbar=yes,menubar=yes,status=yes'); doiWin.focus()">doi:10.1016/j.foreco.2007.11.030</a><br /><br />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 CO<sub>2</sub> effluxes, soil carbon balance, and early tree growth following savannah afforestation in Congo: Comparison of two site preparation treatments. <span style="font-style: italic;">Forest Ecology and Management</span> <span style="font-weight: bold;">255(5-6)</span>:1926-1936 <a href="http://dx.doi.org/10.1016/j.foreco.2007.12.026" target="doilink" onclick="var doiWin; doiWin=window.open('http://dx.doi.org/10.1016/j.foreco.2007.12.026','doilink','scrollbars=yes,resizable=yes,directories=yes,toolbar=yes,menubar=yes,status=yes'); doiWin.focus()">doi:10.1016/j.foreco.2007.12.026</a>Ianhttp://www.blogger.com/profile/01010178962574928062noreply@blogger.com0tag:blogger.com,1999:blog-5461140251004640846.post-63578826548127379672008-03-31T12:11:00.003-05:002008-03-31T12:25:39.719-05:00ReForLan<a href="http://reforlan.bournemouth.ac.uk/">ReForLan</a> (Restoration of Forest Landscapes for Biodiversity Conservation and Rural Development in the Drylands of Latin America) is a new project focusing on<br /><blockquote>the restoration of dryland forest landscapes for biodiversity conservation and rural development in Latin America.</blockquote>The project has received three years of funding (2007-2010) and are working in <a href="http://reforlan.bournemouth.ac.uk/research_sites.html">seven sites</a> around Latin America:<br /><ol><li>Chiapas, Mexico</li><li>Central Veracuz, Mexico</li><li>Oaxaca, Mexico</li><li>Central Valley, Central Chile</li><li>Coastal range, Central Chile</li><li>Northwestern Argentina</li><li>Southwestern Argentina.</li></ol>There's a write-up about the project in the March 2008 issue of <span style="font-style: italic;">Ecological Restoration</span>.Ianhttp://www.blogger.com/profile/01010178962574928062noreply@blogger.com0tag:blogger.com,1999:blog-5461140251004640846.post-23674726829057826692008-03-31T12:05:00.003-05:002008-03-31T12:10:30.548-05:00Other definitionsLast year, Jeremy Bruno posted <a href="http://thevoltagegate.blogspot.com/2007/02/know-your-biomes-iii-tropical-dry.html">a description of dry forest</a> at The Voltage Gate. (He has since moved to <a href="http://scienceblogs.com/voltagegate">ScienceBlogs</a>.) 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.Ianhttp://www.blogger.com/profile/01010178962574928062noreply@blogger.com0tag:blogger.com,1999:blog-5461140251004640846.post-17488387274099953882008-03-31T11:45:00.004-05:002008-03-31T12:02:46.327-05:00So what is tropical dry forest?So what <span style="font-style: italic;">is</span> tropical dry forest? In trying to compile a list of recent dry forest-related literature that question comes to the fore. It's a very familiar question - I spent a lot of time wondering about that early in my grad school career when I thought that I should get a handle on <span style="font-style: italic;">all</span> the literature related to tropical dry forest. (What can I say, I was <s>ambitious</s> naive.) Part of the problem comes from relying on Holdridge's definition - if you define dry forest in relation to precipitation and potential evapotranspiration (which basically boils down to precipitation and temperature), you end up including riparian forests and some forests dependent on ground water - forests that which resemble wetter forests in terms of physiognomy and species composition. When it boils down to it, regardless of rainfall, they don't <span style="font-style: italic;">function</span> as dry forests. In addition, there's the issue of savannas - many savannas fall within the dry forest life zone, but if you look at them as "former" or "potential dry forest" you ignore the fact that they have been grassland for thousands and years. (Other grasslands though, <span style="font-style: italic;">are</span> recent human creations.) Then there are areas that <span style="font-style: italic;">function</span> as dry forest, but get too much rainfall.<br /><br />In selecting literature I am trying to use broad criteria. I'm including deciduous and semi-deciduous forest even if they seem to be a bit on the wet side. I'm also including savannas. In a case like this, it's probably more useful to use a broad definition.Ianhttp://www.blogger.com/profile/01010178962574928062noreply@blogger.com0tag:blogger.com,1999:blog-5461140251004640846.post-59819853994290639112008-03-31T11:16:00.005-05:002008-03-31T11:42:39.161-05:00Recent literatureIn my continuing attempt to catch up on recent literature on tropical dry forests and savannas<br /><br />Oswalt, Sonja N., Thomas J. Brandeis, Christopher W. Woodall. 2008. Contribution of Dead Wood to Biomass and Carbon Stocks in the Caribbean: St. John, U.S. Virgin Islands. <span style="font-style: italic;">Biotropica</span> <span style="font-weight: bold;">40(1)</span>:20–27 <a href="http://dx.doi.org/10.1111/j.1744-7429.2007.00343.x">doi:10.1111/j.1744-7429.2007.00343.x</a> <br /><br />Bellairs, Sean M., Donald C. Franklin, Nicholas J. Hogarth. 2008. A Tropical, Gregariously Semelparous Bamboo Shows No Seed Dormancy. <span style="font-style: italic;">Biotropica</span> <span style="font-weight: bold;">40(1)</span> :28–31 <a href="http://dx.doi.org/10.1111/j.1744-7429.2007.00336.x">doi:10.1111/j.1744-7429.2007.00336.x </a><br /><br />Keuroghlian, Alexine, Donald P. Eaton. 2008. Fruit Availability and Peccary Frugivory in an Isolated Atlantic Forest Fragment: Effects on Peccary Ranging Behavior and Habitat Use. <span style="font-style: italic;">Biotropica</span> <span style="font-weight: bold;">40(1) :</span>62–70 <a href="http://dx.doi.org/10.1111/j.1744-7429.2007.00351.x">doi:10.1111/j.1744-7429.2007.00351.x </a><br /><br />Maffei, Leonardo, Andrew J. Noss. 2008. How Small is too Small? Camera Trap Survey Areas and Density Estimates for Ocelots in the Bolivian Chaco . <span style="font-style: italic;">Biotropica</span> <span style="font-weight: bold;">40(1)</span> :71–75 <a href="http://dx.doi.org/10.1111/j.1744-7429.2007.00341.x">doi:10.1111/j.1744-7429.2007.00341.x </a><br /><br />Martins, Eduardo Guimarães, Márcio Silva Araújo, Vinícius Bonato, Sérgio Furtado dos Reis. 2008. Sex and Season Affect Individual-Level Diet Variation in the Neotropical Marsupial <i>Gracilinanus microtarsus</i> (Didelphidae). <span style="font-style: italic;">Biotropica</span> <span style="font-weight: bold;">40(1)</span> :132–135 <a href="http://dx.doi.org/10.1111/j.1744-7429.2007.00319.x">doi:10.1111/j.1744-7429.2007.00319.x </a><br /><br />Casandra Reyes-García, Howard Griffiths, Emmanuel Rincón, Pilar Huante. 2008. Niche Differentiation in Tank and Atmospheric Epiphytic Bromeliads of a Seasonally Dry Forest <br /><span style="font-style: italic;">Biotropica </span><span style="font-weight: bold;">40(2)</span> :168–175 <a href="http://dx.doi.org/10.1111/j.1744-7429.2007.00359.x">doi:10.1111/j.1744-7429.2007.00359.x</a> <br /><br />Philip D. Round, George A. Gale (2008) Changes in the Status of <i>Lophura</i> Pheasants in Khao Yai National Park, Thailand: A Response to Warming Climate? <br /><span style="font-style: italic;">Biotropica </span><span style="font-weight: bold;">40(2)</span> :225–230 <a href="http://dx.doi.org/10.1111/j.1744-7429.2007.00363.x">doi:10.1111/j.1744-7429.2007.00363.x</a> <br /><br />Reuber A. Brandão, Alexandre F. B. Araújo (2008) Changes in Anuran Species Richness and Abundance Resulting from Hydroelectric Dam Flooding in Central Brazil <br /><span style="font-style: italic;">Biotropica </span><span style="font-weight: bold;">40(2)</span> :263–266 <a href="http://dx.doi.org/10.1111/j.1744-7429.2007.00356.x">doi:10.1111/j.1744-7429.2007.00356.x </a>Ianhttp://www.blogger.com/profile/01010178962574928062noreply@blogger.com3tag:blogger.com,1999:blog-5461140251004640846.post-31141597149491704432008-03-29T14:19:00.003-05:002008-03-29T15:24:51.608-05:00Recent literatureSome recent literature published on tropical dry forests and savannas.<br /><br />Poorter, Lourens, William Hawthorne, Frans Bongers, Douglas Sheil. 2008. Maximum size distributions in tropical forest communities: relationships with rainfall and disturbance. <span style="font-style: italic;">Journal of Ecology</span> <a href="http://dx.doi.org/10.1111/j.1365-2745.2008.01366.x">doi:10.1111/j.1365-2745.2008.01366.x</a> (early online)<br /><br />Klop, Erik and Janneke van Goethem. 2008. Savanna fires govern community structure of ungulates in Bénoué National Park, Cameroon. <span style="font-style: italic;">Journal of Tropical Ecology</span> 24(1):39-47 <a href="http://dx.doi.org/10.1017/S0266467407004609">doi: 10.1017/S0266467407004609</a><br /><br />de Lima, Renato A. Ferreira, Adriana M. Zanforlin Martini, Sérgius Gandolfi and Ricardo Ribeiro Rodrigues. 2008. Repeated disturbances and canopy disturbance regime in a tropical semi-deciduous forest. <span style="font-style: italic;">Journal of Tropical Ecology</span> 24(1):85-93 <a href="http://dx.doi.org/10.1017/S0266467407004658">doi: 10.1017/S0266467407004658</a><br /><br />González-Ruiz, Teresa, Víctor J. Jaramillo, Juan José Peña Cabriales and Arturo Flores. 2008. Nodulation dynamics and nodule activity in leguminous tree species of a Mexican tropical dry forest. <span style="font-style: italic;">Journal of Tropical Ecology</span> 24(1):107-110 <a href="http://dx.doi.org/10.1017/S0266467407004634">doi: 10.1017/S0266467407004634</a><br /><br />Castanho, Camila de Toledo and Alexandre Adalardo de Oliveira. 2008. Relative effect of litter quality, forest type and their interaction on leaf decomposition in south-east Brazilian forests. <span style="font-style: italic;">Journal of Tropical Ecology</span> 24(2):149-156 <a href="http://dx.doi.org/10.1017/S0266467407004749">doi: 10.1017/S0266467407004749</a><br /><br />Janos, David P., John Scott and David M. J. S. Bowman. 2008. Temporal and spatial variation of fine roots in a northern Australian Eucalyptus tetrodonta savanna. <span style="font-style: italic;">Journal of Tropical Ecology</span> 24(2):177-188 doi: <a href="http://dx.doi.org/10.1017/S0266467408004860">10.1017/S0266467408004860</a>Ianhttp://www.blogger.com/profile/01010178962574928062noreply@blogger.com0tag:blogger.com,1999:blog-5461140251004640846.post-54460640354254941752008-03-25T11:10:00.001-05:002008-03-25T11:13:00.652-05:00Disturbance and recovery in tropical dry forests[Crosspost from <a href="http://ianramjohn.wordpress.com/2008/03/25/disturbance-and-recovery-in-tropical-dry-forests/">Further Thoughts</a>]<br />When people think about the destruction and degradation of tropical forests, they tend to focus on rainforests. Tropical dry forests tend to get overlooked. They aren’t as striking - no cathedral-like understorey, no mind-boggling biodiversity. But more importantly, they often just aren’t there. Over much of their potential range they have simply been erased from the landscape. They may have covered as much as 42% of the land area in the tropics<sup>1</sup>, but have been reduced to less than 27% of their former range in Mexico<sup>2</sup>, and as little as 2% in Central America<sup>3</sup> and New Caledonia<sup>4</sup>. <p>Despite the fact this, tropical dry forests are often seen as being quite well-adapted to human disturbance. Being less species-rich than wetter forests, they tend to support fewer rare species, and may be less extinction-prone. In addition, dry forests are dominated by trees that sprout after being cut. This means that if you cut down a patch of dry forest, most of the stumps will re-sprout. This type of recovery is much quicker than you would get if the trees had to germinate from seeds - not only does it take much longer for seedlings to grow large (stump sprouts can draw on resources stored in the roots of the tree), but there’s likely to be a time lag as seeds disperse into the area from surviving trees (tropical forests tend to lack long-lived seedbanks).</p> <p>Much of our understanding of succession in tropical dry forests comes from Jack Ewel’s dissertation work. Ewel looked at the effect of cutting and herbicide application on succession in a series of plots across the Neotropics. One of his important findings was the dry forests were quicker to recover their stature that wetter forests. Since most of the recovery comes from stump sprouts, the recovering forest is also close to the original forest in terms of species composition.</p> <p>While lightly used dry forest sites recover rapidly, recovery is slower in more intensively used sites. Seedling survival rates are very low in dry forests - while seedlings establish in the wet season, most (often all) of them die in the subsequence dry season. So while intensively used sites in Guánica Forest recovered well in terms of structure, biomass and leaf fall in 50 years after abandonment, the recovery of species composition was very slow<sup>6</sup>.</p> <p>Resilience is the rate of recovery of disturbed sites to their pre-disturbed state. Ewel’s work helped to establish the idea that dry forests are more resilient than wetter forests. But there is no single rate - or pathway - of recovery. Measures of “recovery” depend on the parameter measured - canopy height, biomass, species richness, nutrient cycling… It also depends on the baseline against which recovery is measured: if the same site is measured before and after disturbance, you need to know if the site represented “mature” forest before disturbance. If another site is used, you need to wonder if it is really representative of initial conditions in your experimental plot.</p> <p>In a forthcoming paper<sup>7</sup> in the journal <i>Biotropica</i>, Edwin Lebrija-Trejos and coauthors looked at what it really means to say that tropical dry forests are more resilient than wetter forests. They looked at a sequence of 15 sites in Oaxaca, Mexico, which had been cultivated and then abandoned for 0-40 years, and compared them with nearby mature forest. All of the sites had been cultivated for a short period (1-2 years) and then abandoned without being converted to pasture<sup>8</sup>. They considered a variety of different ways to measure resilience - they looked at forest height, plant density, basal area (the area occupied by tree stems), crown cover, species richness, species density (number of species per 100 m<sup>2</sup>), Shannon evenness and Shannon diversity. Not surprisingly, they found that certain features (canopy height, plant density, crown cover) recovered rapidly (in less than 20 years) while others (including basal area and species richness) had not recovered after 40 years.</p> <p>When compared their sites with other comparable studies, they found that their sites were among the quickest to recover canopy cover and height. On the other hand, they found that their sites were among the slowest to recover species diversity and average in terms of the recovery of species richness. Overall, in terms of the structural measures that Ewel focussed on, it’s reasonable to conclude that dry forests <i>are</i> more resilient that wetter forests. On the other hand, with regards to things like basal area and species richness, the assertion of resilience for dry forests isn’t well supported.</p> <ol><li>Brown, S., and A. E. Lugo. 1982. The storage and production of organic matter in tropical forests and their role in the global carbon cycle. <i>Biotropica</i> <b>14</b>:161-187.</li><li>Trejo, I., and R. Dirzo. 2002. Floristic diversity of Mexican seasonally dry tropical forests. <i>Biodiversity and Conservation</i> <b>11</b>:2063–2084</li><li>Janzen, D. H. 1988. Tropical dry forests: The most endangered major ecosystem. <i>In</i> E. O. Wilson (Ed.). <i>Biodiversity</i>, pp. 130–137. National Academy Press, Washington, DC</li><li>Gillespie, T. W., and T. Jaffré. 2003. Tropical dry forests in New Caledonia. <i>Biodiversity and Conservation</i> <b>12</b>:1687–1697.</li><li>Ewel, J. J. 1971. <i>Experiments in arresting succession with cutting and herbicide in five tropical environments</i>. Ph.D. University of North Carolina, Chapel Hill.</li><li>Molina Colón, S., and A. E. Lugo. 2006. Recovery of a subtropical dry forest after abandonment of different land uses. <i>Biotropica</i> <b>38</b>:354–364.</li><li>Lebrija-Trejos, E., Bongers, F., Pérez-García, E.A., Meave, J.A. 2008. Successional Change and Resilience of a Very Dry Tropical Deciduous Forest Following Shifting Agriculture. <span style="font-style: italic;">Biotropica</span> DOI: <a href="http://dx.doi.org/10.1111/j.1744-7429.2008.00398.x">10.1111/j.1744-7429.2008.00398.x</a></li><li>Conversion to pasture tends to slow recovery significantly; not only does the prolonged period eliminate almost all root stocks, it also establishes a grassy layer that makes it more difficult for tree seedlings to establish.<br /></li></ol>Ianhttp://www.blogger.com/profile/01010178962574928062noreply@blogger.com1tag:blogger.com,1999:blog-5461140251004640846.post-19829373192480433752008-02-27T20:46:00.004-06:002008-03-31T11:46:57.893-05:00Introducing tropical dry forests - part IAlthough most people are familiar with tropical rainforests, fewer people are familiar with tropical dry forests. Despite this, they are an important tropical biome - according to Leslie Holdridge's definition of dry forests, they may once have covered 42% of the land mass in the tropics. But most people, when you say "tropical dry forest" reply by asking "tropical rainforest?"<br /><br />So what are dry forests? While Holdridge's system was complicated, in the simplest terms they are forests were potential evapotranspiration exceeded precipitation. In other words, averaged over the year, the amount of rain that falls is less than the total amount of water that <span style="font-style: italic;">could</span> be lost through transpiration and evapouration, if it were available. On average, the vegetation is water stressed. Classic dry forests are dominated by dry-season deciduous trees (trees that drop their leaves in the dry season), and they have five or more months with less than 100 mm of rainfall. There are exceptions - dry forests in Hawai'i don't have that pronounced a dry season, but they are still dry overall. Holdridge's system was a first approximation - there are areas that meet his definition for dry forest which appear and behave like wetter forests, and they there are forests in higher rainfall areas that resemble dry forests in their species composition and ecological function because they grow on steep slopes with thin soils, or because they are subject to desiccating winds.Ianhttp://www.blogger.com/profile/01010178962574928062noreply@blogger.com0tag:blogger.com,1999:blog-5461140251004640846.post-90106078066504499602008-02-27T12:29:00.000-06:002008-02-27T14:28:36.923-06:00An experiment"If you build it they will come"<br /><br />Really? This is inspired by a <a href="http://bayblab.blogspot.com/2008/02/state-of-science-blogging.html">controversial post</a> at Bayblab regarding the popularity (or lack thereof) of solid peer reviewed science. It's just an experiment.<br /><br />The rules are<br /><ol><li>Science only (except as noted under the meta tag).<br /></li><li>Posts can cover any topic related to tropical dry forests.<br /></li><li>Posts can cover other relevant material about forest ecology which, while not specifically <span style="font-style: italic;">about</span> dry forest ecology is still otherwise relevant.</li><li>Wherever possible, blog posts should comment on peer-reviewed literature.<br /></li></ol>Ianhttp://www.blogger.com/profile/01010178962574928062noreply@blogger.com0