Reynaldo Linares-Palomino

Plant diversity patterns in neotropical dry forests and their conservation implications

Seasonally dry tropical forests are distributed across Latin America and the Caribbean and are highly threatened, with less than 10% of their original extent remaining in many countries. Using 835 inventories covering 4660 species of woody plants, we show marked floristic turnover among inventories and regions, which may be higher than in other neotropical biomes, such as savanna. Such high floristic turnover indicates that numerous conservation areas across many countries will be needed to protect the full diversity of tropical dry forests. Our results provide a scientific framework within which national decision-makers can contextualize the floristic significance of their dry forest at a regional and continental scale.

Forgotten forests - issues and prospects in biome mapping using Seasonally Dry Tropical Forests as a case study

BackgroundSouth America is one of the most species diverse continents in the world. Within South America diversity is not distributed evenly at both local and continental scales and this has led to the recognition of various areas with unique species assemblages. Several schemes currently exist which divide the continental-level diversity into large species assemblages referred to as biomes. Here we review five currently available biome maps for South America, including the WWF Ecoregions, the Americas basemap, the Land Cover Map of South America, Morrones Biogeographic regions of Latin America, and the Ecological Systems Map. The comparison is performed through a case study on the Seasonally Dry Tropical Forest (SDTF) biome using herbarium data of habitat specialist species.ResultsCurrent biome maps of South America perform poorly in depicting SDTF distribution. The poor performance of the maps can be attributed to two main factors: (1) poor spatial resolution, and (2) poor biome delimitation. Poor spatial resolution strongly limits the use of some of the maps in GIS applications, especially for areas with heterogeneous landscape such as the Andes. Whilst the Land Cover Map did not suffer from poor spatial resolution, it showed poor delimitation of biomes. The results highlight that delimiting structurally heterogeneous vegetation is difficult based on remote sensed data alone. A new refined working map of South American SDTF biome is proposed, derived using the Biome Distribution Modelling (BDM) approach where georeferenced herbarium data is used in conjunction with bioclimatic data.ConclusionsGeoreferenced specimen data play potentially an important role in biome mapping. Our study shows that herbarium data could be used as a way of ground-truthing biome maps in silico. The results also illustrate that herbarium data can be used to model vegetation maps through predictive modelling. The BDM approach is a promising new method in biome mapping, and could be particularly useful for mapping poorly known, fragmented, or degraded vegetation. We wish to highlight that biome delimitation is not an exact science, and that transparency is needed on how biomes are used as study units in macroevolutionary and ecological research.

Large-scale patterns of turnover and Basal area change in Andean forests.

General patterns of forest dynamics and productivity in the Andes Mountains are poorly characterized. Here we present the first large-scale study of Andean forest dynamics using a set of 63 permanent forest plots assembled over the past two decades. In the North-Central Andes tree turnover (mortality and recruitment) and tree growth declined with increasing elevation and decreasing temperature. In addition, basal area increased in Lower Montane Moist Forests but did not change in Higher Montane Humid Forests. However, at higher elevations the lack of net basal area change and excess of mortality over recruitment suggests negative environmental impacts. In North-Western Argentina, forest dynamics appear to be influenced by land use history in addition to environmental variation. Taken together, our results indicate that combinations of abiotic and biotic factors that vary across elevation gradients are important determinants of tree turnover and productivity in the Andes. More extensive and longer-term monitoring and analyses of forest dynamics in permanent plots will be necessary to understand how demographic processes and woody biomass are responding to changing environmental conditions along elevation gradients through this century.

Forest conservation: Remember Gran Chaco—Response

WE AGREE WITH Kuemmerle et al. that the forests in the Gran Chaco region are under massive threat, underprotected, and deserving of greater attention from scientists and conservationists. We could have included the Chaco woodlands in our analyses, and their distinctive flora would have reinforced

The Effects of Area and Habitat Heterogeneity on Bird Richness and Composition in High Elevation Wetlands (“Bofedales”) of the Central Andes of Peru

We assessed area and habitat heterogeneity effects on avian richness and composition in bofedales that differed in size and microhabitat diversity. We analyzed data collected in 2 seasons and 24 bofedales using General Linear Models, Ordinary Least Square models to establish the relationship of predictor variables on richness and Akaike Information Criterion for model selection. We evaluate composition classifying species into groups using Bray Curtis ordination, followed by Multiple Response Permutation Procedure to test for differences among groups, and Indicator Species Analysis to identify species. Bofedales differed in richness (F = 5.1, p < 0.001) and microhabitat diversity (F = 23.4, p < 0.001), but no seasonal differences emerged (p > 0.05). The best model indicates that 54% of variance in richness was explained by area and microhabitat diversity, however, a tendency to decrease in microhabitat diversity as area increases, suggests a relatively more important role of area. Results are supported by composition, as microhabitats not only differed pairwise (T = −94.14, A = 0.601, p < 0.001) and had significant indicator species (p < 0.05), but because its differential contribution to richness, as some microhabitats were more speciose than others. As such, few species-rich microhabitats may contribute more to richness than many species-poor ones which is not predicted by the habitat heterogeneity hypothesis. Disentangling the influence of area and habitat heterogeneity on species richness is important to establish conservation priorities that ensure bofedales integrity under imminent climate change.ResumenEvaluamos el efecto del área y la heterogeneidad del hábitat en la riqueza y composición de aves en bofedales que difieren en tamaño y diversidad de microhábitats. Los datos recopilados en 2 estaciones y 24 bofedales fueron analizados usando Modelos Generales Lineales, Modelos de Mínimos Cuadrados Ordinarios para establecer la relación entre las variables predictivas y la riqueza, y el Criterio de Información de Akaike para seleccionar los modelos. Evaluamos la composición de especies clasificándolas en grupos con el Ordenamiento de Bray Curtis, seguido por el Análisis de Permutación de Respuesta Múltiple para detectar diferencias entre los grupos, y el Análisis de Especies Indicadoras para identificar las especies. Los bofedales difieren en riqueza (F = 5.1, p < 0.001) y diversidad de microhábitats (F = 23.4, p < 0.001), pero no hallamos diferencias estacionales (p > 0.05). El modelo seleccionado indica que el área y la diversidad de microhábitats explican 54% de la varianza en la riqueza, sin embargo, encontramos una tendencia inversa entre la diversidad de microhábitats y el área, la cual sugiere un papel relativamente más importante del área en la riqueza de especies. Nuestros resultados son respaldados por los datos de composición, ya que los microhábitats no sólo fueron diferentes en comparaciones pareadas (T = −94.14, A = 0.601, p < 0.001) y estuvieron representados significativamente por especies indicadoras (p < 0.05), sino que contribuyeron diferencialmente con la riqueza. Así, pocos microhábitats ricos en especies contribuirían más a la riqueza que varios microhábitats pobres en especies lo cual no concuerda con las predicciones de la hipótesis de heterogeneidad del hábitat. Determinar la influencia que el área y la heterogeneidad tienen en la riqueza de especies es importante para establecer prioridades de conservación que garanticen la integridad de los bofedales ante el inminente cambio climático.

Forest conservation: Humans' handprints—Response

WE AGREE WITH Levis et al. that humans have influenced dry forests since their first arrival in the neotropics. This long interaction has had major effects, not least in leading to widespread destruction of this now highly threatened vegetation ([ 1 ][1]). It is also possible, as pointed out by

Identifying and Avoiding Sensitive Habitats in Petroleum Operations

Defining and understanding the habitats in which a company is operating is a key step toward the reduction of impacts on biodiversity. Identification of vegetation types is a commonly-used method for mapping an area of operations, and these vegetation types are often used as a surrogate for plant and animal habitats, but defining these types too finely may result in limited biological importance of these types for plants and animals, and may complicate the conservation planning process. Instead, habitat maps based on more coarse-scale but biologically important data such as elevation and geologic history can result in more useful maps of plant and animal communities and can lead to better land management during operations. We created habitat maps for Blocks 39 and 57 in northeastern and south central Peru, respectively, using Landsat imagery and elevation data. In Block 39, three different geological formations, or habitat types, were identified in the map, while four were identified in Block 57. In order to confirm that the habitats identified in this study are biologically distinct in terms of plant and animal communities, CCES researchers assessed soil samples and a variety of taxonomic groups including ferns, birds, bats, amphibians and reptiles in each. The protocol requires a minimum of five days sampling for each taxonomic group in a minimum of four different areas within each distinct habitat in order to ensure thorough data collection. We then use this data to test and redefine the boundaries of habitats, and to identify habitats with communities of plants and animals of special conservation concern. In the cases of Blocks 39 and 57, recommendations were made to the company regarding where to avoid or limit operations, in order to reduce negative impacts on special habitats and improve the likelihood and cost-effectiveness of habitat restoration post-operations.