Tropical Semideciduous Forest Research Articles

Ampliación de la distribución geográfica de Lampronycteris brachyotis en la península de Yucatán

We registered one juvenile female Lampronycteris brachyotis in a tropical semideciduous forest of Espita county, Yucatán. This is the first record of the species in the state of Yucatán, which extends its distribution in the Peninsula.

Recommendations for monitoring avian populations with point counts: a case study in southeastern Brazil

In the northern hemisphere, bird counts have been fundamental in gathering data to understand population trends. Due to the seasonality of the northern hemisphere, counts take place during two clearly defined moments in time: the breeding season (resident birds) and winter (after migration). Depending on location, Neotropical birds may breed at any time of year, may or may not migrate, and those patterns are not necessarily synchronous among species. Also in contrast to the northern hemisphere, population trends and the impact of rapid urbanization and deforestation are unknown and unmonitored. Throughout one year, we used point counts to better understand temporal patterns of bird species richness and relative abundance in the state of São Paulo, southeastern Brazil, to examine how to implement similar bird counts in tropical America. We counted birds twice each day on 10 point transects (20 points day‑1), separated by 200 m, with a 100 m limited detection radius in a semideciduous tropical forest. Both species richness and bird abundance were greater in the morning, but accumulation curves suggest that longer-duration afternoon counts would reach the same total species as in morning counts. Species richness and bird abundance did not vary seasonally and unique species were counted every month; relatively few species (20%) were present in all months. Most (84%) known forest species in the area were encountered. We suggest that point counts can work here as they do in the northern hemisphere. We recommend that transects include at least 20 points and that the simplest timing of bird counts would also be seasonal, using timing of migration of austral migrants (and six months later) to coordinate counts. We propose that bird counts in Brazil, and elsewhere in Latin America, would provide data to help understand population trends, but would require greater effort than in temperate latitudes due to greater species richness and different dynamics of reproduction and migration. With collaboration among ornithologists and coordinated bird surveys, we may develop a technique for the tropics that would yield information for population trends and conservation of birds, similar to counts in temperate latitudes.

Annual Variation in Flowering Phenology, Pollination, Mating System, and Pollen Yield in Two Natural Populations of Schima wallichii (DC.) Korth

Background. Schima wallichii is a highly valuable tree of tropical forest in north-east Himalaya region that grows naturally in a wide range of altitudes between 750 and 2400 m asl with varying environments. Flowering phenology of tropical tree species at population level is generally ignored and therefore a detailed knowledge of flowering and fruiting patterns of important multipurpose tree species is critical to the successful management of forest genetic resources. Materials and Methods. The study was conducted at two different altitudes (i.e., 750 m and 900 m asl) in the tropical semideciduous forest of north-east Himalaya. The floral phenology including flowering synchrony in the populations, anthesis, anther dehiscence, stigma receptivity, pollinators visitation frequency, and mating system including index of self-incompatibility were worked out in Schima wallichii according to the ear-marked standard methods given by various scientists for each parameter. Results. The flowering period in Schima wallichii varied from 33 to 42 days with mean synchrony of 0.54 to 0.68 between the populations. The stigma was receptive up to 2.5 days only and showed slightly protandrous type of dichogamy. Average pollen production ranged between 6.90 × 107 pollen per tree in 2007 and 15.49 × 108 pollen per tree in 2011. A three-year masting cycle was noticed in this species. The frequency of visitation of honey bees was fairly high (5.2 ± 1.12 visits/flower/hour) as compared to other pollinators. The hand pollination revealed maximum fruit (74.2 ± 5.72%) and seed (70.8 ± 7.46%) settings. Conclusions. The variation in flowering phenology and pollen yield individually and annually along with temporal separation in anther dehiscence and pollinator's visitation cause pollen limited reproduction, which ultimately influences the reproductive success in Schima wallichii.

Roving revisited, towards an optimum throughfall sampling design

AbstractAdditional aspects regarding the optimum fixed and roving sampling techniques, to those already explored in a previous authors’ throughfall study, are further investigated here. The roving technique consists in the random repositioning, with a frequency fr, of N throughfall gauges among M positions (M > N), oppositely to the fixed or stationary arrangement where N = M. Both fixed and roving optimum sampling techniques of 100 monitored throughfall events sampled with 200 fixed gauges under a semideciduous tropical rain forest in Panama were investigated by means of Monte‐Carlo numerical experiments. Mean dispersion was shown to be always smaller in the roving versus the fixed gauge arrangement, independently of the relocation frequency studied (fr = 0.1, 0.2, 0.5, 1), such that all roving schemes with N ≥ 50 gauges lay within ±5% of the mean cumulative throughfall. Results indicated that a low variability, high precision, and accuracy are obtained with a modest relocation frequency fr = 0.2 (i.e. a relocation every five episodes of the original 100 measured events) and N = 30 roving gauges, with no significant improvement worth the extra field work beyond fr > 0.2 and N >30. Only by increasing the number of roving positions from M < < 200 to M = 200, the precision and accuracy of the mean estimate were improved without comprising additional labour. Hence, a roving sampling scheme which relocates gauges over completely new fresh sites each roving cycle is recommended for future throughfall studies. Finally, we designed an a priori sampling strategy which permitted us to conclude that using only the first 20 out of the total 100 measuring events, for the remaining 80 throughfall field measurements, N = 40 roving gauges (i.e. five time less than the originally 200 gauges displayed) would have been sufficient for ensuring ≤5% error, expressed as percentage of the mean cumulative throughfall. Copyright © 2012 John Wiley & Sons, Ltd.

A Second Locality in Jalisco, México, for the CentipedeEctonocryptoides quadrimeropusShelley & Mercurio, 2005 (Scolopendromorpha: Scolopocryptopidae: Ectonocryptopinae)

We report a second locality from coastal Jalisco, the third from Mexico, and four newly collected individuals of the rarely encountered centipede, Ecto no cryp toides quadrimeropus Shelley and Mercurio, 2005, and the subfamily Ecto no cryptopinae. Three of the individuals were found on the substrate be neath a rock and one in humus. They were taken by the first author on 30 June and 5 and 8 July 2009 at two sites in a suburb of Puerto Vallarta, Jalisco, Mexico (Site 1: three specimens in the gardens of the University of Guadalajara campus northeast of Puerto Vallarta, about 1 km from Ixtapa, 20o 42' N, 5o 13' W, 10 m elev. Site 2: one specimen in humus of tropical semideciduous forest northeast of Puerto Vallarta, around 1 km from Las Palmas, 20o 49' N, 105o 4' W, 160 m elev.). Two of the centipedes were sent to Department of Organismic and Evo lu tionary Biology, Museum of Comparative Zoology, Harvard University, Cam bridge, Massachusetts, USA, for a comparative anatomical study and mole cu lar phylogenetic analyses (Koch et al., 2010; Vahtera et al., 2012), one was deposited in the Coleccion Entomologica del Centro de Estudios en Zoologia de la Universidad de Guadalajara (CZUG), and the last one in the Virginia Museum of Natural History, Martinsville, Virgina, USA. The type locality, where two syntypes were taken –Biological Station Chamela, Universidad Nacional Autonoma de Mexico– is on the southern coast of Jalisco ca. 157 km south of Puerto Vallarta (Shelley and Mercurio, 2005), and Shelley (2009) reported a specimen from Tehuacan, Puebla, in central Mexico. These seven Ectonocryptopinae are augmented by a purported new species in Belize, Ectonocryptoides sandrops Schileyko, 2009 (Schileyko 2009), and the holotype of Ectonocryptops kraepelini Crabill 1977, from Colima (Crabill, 1977; Shelley and Mercurio, 2005; 2008) to make nine total specimens of the subfamily. Anatomically the Puerto Vallarta centipedes agree closely with the original description of Ectonocryptoides quadrimeropus and display the yellowish color reported for preserved individu378 ENTOMOLOGICAL NEWS

Primeros registros de Calocitta colliei para Michoacán, México, localidad de distribución más suroriental de la especie

Reportamos la primera localidad en el estado de Michoacán con presencia de la urraca-hermosa cara negra (Calocitta colliei). Obtuvimos cuatro registros distintos durante el período de 2006 a 2010, en los meses de noviembre a mayo, con un total de 11 individuos. Obtuvimos los registros mediante el método de puntos de conteo en el interior de una cañada tropical localizada dentro del parque estatal “Chorros del Varal”, entre los municipios de Los Reyes y Peribán, en un área cubierta por bosque tropical subperennifolio y bosque tropical caducifolio; siendo en este último tipo de vegetación donde obtuvimos tres de los cuatro registros. Con estos nuevos registros se amplía la distribución de C. colliei aproximadamente 130 km al sureste de su distribución reconocida. También se incrementa el número de especies del listado de aves del estado de Michoacán a 548, y de la familia Corvidae a 7.

Hydro-physical characterization of soils under tropical semi-deciduous forest

The study of the hydro-physical behavior in soils using toposequences is of great importance for better understanding the soil, water and vegetation relationships. This study aims to assess the hydro-physical and morphological characterization of soil from a toposequence in Galia, state of Sao Paulo, Brazil). The plot covers an area of 10.24 ha (320 × 320 m), located in a semi-deciduous seasonal forest. Based on ultra-detailed soil and topographic maps of the area, a representative transect from the soil in the plot was chosen. Five profiles were opened for the morphological description of the soil horizons, and hydro-physical and micromorphological analyses were performed to characterize the soil. Arenic Haplustult, Arenic Haplustalf and Aquertic Haplustalf were the soil types observed in the plot. The superficial horizons had lower density and greater hydraulic conductivity, porosity and water retention in lower tensions than the deeper horizons. In the sub-superficial horizons, greater water retention at higher tensions and lower hydraulic conductivity were observed, due to structure type and greater clay content. The differences observed in the water retention curves between the sandy E and the clay B horizons were mainly due to the size distribution, shape and type of soil pores.

CARACTERIZAÇÃO MORFOLÓGICA DAS PLÂNTULAS DE CINCO ESPÉCIES ARBÓREAS DA FLORESTA ESTACIONAL SEMIDECIDUAL, BRASIL

As espécies arbóreas Astronium graveolens (Anacardiaceae), Cedrela fissilis (Meliaceae), Gallesia integrifolia (Phytolaccaceae), Parapiptadenia rigida (Fabaceae) e Tabebuia avellanedae (Bignoniaceae) ocorrem em remanescentes da Floresta Estacional Semidecidual do norte e noroeste paranaense e interior do estado de São Paulo. As plântulas dessas espécies foram descritas morfologicamente com o objetivo de subsidiar sua identificação em campo. As plântulas analisadas mostraram-se distintas desde suas folhas cotiledonares até os eófilos e metáfilos, podendo ser localizadas facilmente na comunidade vegetal. As folhas das cinco espécies são pecioladas e apenas C. fissilis e T. avellanedae apresentaram eófilos. Cedrela fissilis apresenta eófilos do tipo composto, trifoliado, com margem íntegra, e T. avellanedae, eófilos do tipo simples com margem serreada. As plântulas de G. integrifolia possuem metáfilos simples, e as de C. fissilis, T. avellanedae e A. graveolens têm metáfilos compostos, enquanto que nas plântulas de P. rigida os metáfilos são recompostos. Como as plântulas são visualmente distintas, a identificação em campo torna-se possível.

An assessment of natural and human disturbance effects on Mexican ecosystems: current trends and research gaps

Mexico harbors more than 10% of the planet’s endemic species. However, the integrity and biodiversity of many ecosystems is experiencing rapid transformation under the influence of a wide array of human and natural disturbances. In order to disentangle the effects of human and natural disturbance regimes at different spatial and temporal scales, we selected six terrestrial (temperate montane forests, montane cloud forests, tropical rain forests, tropical semi-deciduous forests, tropical dry forests, and deserts) and four aquatic (coral reefs, mangrove forests, kelp forests and saline lakes) ecosystems. We used semi-quantitative statistical methods to assess (1) the most important agents of disturbance affecting the ecosystems, (2) the vulnerability of each ecosystem to anthropogenic and natural disturbance, and (3) the differences in ecosystem disturbance regimes and their resilience. Our analysis indicates a significant variation in ecological responses, recovery capacity, and resilience among ecosystems. The constant and widespread presence of human impacts on both terrestrial and aquatic ecosystems is reflected either in reduced area coverage for most systems, or reduced productivity and biodiversity, particularly in the case of fragile ecosystems (e.g., rain forests, coral reefs). In all cases, the interaction between historical human impacts and episodic high intensity natural disturbance (e.g., hurricanes, fires) has triggered a reduction in species diversity and induced significant changes in habitat distribution or species dominance. The lack of monitoring programs assessing before/after effects of major disturbances in Mexico is one of the major limitations to quantifying the commonalities and differences of disturbance effects on ecosystem properties.

Seasonal variations in litter production and its relation with MODIS vegetation indices in a semi-deciduous forest of Mato Grosso

Litter production is related to canopy processes including the timing and amount of leaf development, reproduction and net primary production. However, quantifying spatial and temporal patterns in litter production is complicated in Amazonian semi-deciduous forests because of high spatial heterogeneity and seasonal variation in rainfall. Here, we use monthly measurements of litter production and Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) composites over a 6-year period to assess whether MODIS can be used to quantify litter production of tropical semi-deciduous forests. Original MODIS NDVI and EVI values were poorly related to the seasonal periodicity in litter production, but after using singular spectrum analysis (SSA) signal extraction techniques, clear relationships between litter production and the NDVI and EVI emerged. These results indicate that MODIS NDVI and EVI data are useful for detecting temporal patterns in litter production for Amazonian semi-deciduous forests if signal extraction analyses such as SSA are conducted.

Population ecology of small rodents and marsupials in a semi-deciduous tropical forest of the southeast Pantanal, Brazil

The Pantanal is a South American biome characterized by extensive plains and stark environmental seasonality. Several habitats are subject to annual flooding, forcing small mammal species to aggregate in dry forest patches, which most likely influences their population dynamics and life history strategies. In order to investigate the seasonal influence on the life history traits of these small mammals, we conducted a 2-year mark-recapture study in the southeastern region of the Brazilian Pantanal (Nhecolândia) and analyzed the population dynamics of the most abundant small mammal species with the jackknife estimator. A trapping effort of 21,560 trap-nights resulted in 615 individuals in 1,171 captures (success = 5.43%). Three species of rodents - Oecomys mamorae (Thomas, 1906), Thrichomys pachyurus (Wagner, 1845), and Clyomys laticeps (Thomas, 1841) - and three species of marsupials - Gracilinanus agilis (Burmeister, 1854), Thylamys macrurus (Olfers, 1818), and Monodelphis domestica (Wagner, 1842) - were obtained. The most abundant species was O. mamorae, followed by G. agilis and T. pachyurus. Oecomys mamorae was more abundant in the wet season and presented an opportunistic reproductive strategy. Gracilianus agilis displayed increased population sizes in the dry season and synchronized, seasonal reproduction during the rainy season. Thrichomys pachyurus had a small population size, delayed response to variations in environmental conditions and higher reproductive rates in the dry season. All species revealed different life history strategies (seasonal, opportunistic or delayed response to environmental variations), coinciding with periods of higher resource availability in order to maximize survival.

Temporal patterns of net CO2exchange for a tropical semideciduous forest of the southern Amazon Basin

[1] The carbon cycling of tropical ecosystems has received considerable attention over the last 1–2 decades; however, interactions between climate variation and tropical forest net ecosystem CO2 exchange (NEE) are still uncertain. To reduce this uncertainty, and assess the biophysical controls on NEE, we used the eddy covariance method over a 3 year period (2005–2008) to measure the CO2 flux and energy balance for a 25–28 m tall, mature tropical semideciduous forest located near Sinop Mato Grosso, Brazil. The study period encompassed warm-dry, cool-wet, and cool-dry climate conditions, and based on previous research, we hypothesized that the net CO2 accumulation of the semideciduous forest would be lower during periods of drought. Using time series of the enhanced vegetation index (EVI), a NEE-light-use model, and path analysis, we found that the estimated quantum yield (a′, μmol CO2μmol photons−1) was directly affected by temporal variations in the EVI, precipitation, and photosynthetically active radiation (PAR), while the optimal rate of gross primary production (FGPP,opt, μmol m−2 s−1) was directly affected by the EVI and PAR. However, indirect effects of precipitation on the a′ and FGPP,opt were stronger than direct effects because variations in precipitation also lead to variations in the EVI and the atmospheric vapor pressure deficit (VPD). Daytime ecosystem respiration (FRE,day, μmol m−2 s−1) was directly affected by temporal variations in temperature and VPD and indirect effects of other variables were of lesser importance. Net ecosystem CO2 uptake was often higher in the dry season than the wet season, not because of a dry season “green-up” but because rates of ecosystem respiration declined relatively more than rates of canopy photosynthesis. Over interannual timescales, average daily NEE increased over the 3 year study period and was highest in 2007–2008, which was also the driest year in terms of rainfall. However, 2007–2008 was also the coolest year during the 3 year study period, and the low temperature appeared to compensate for the low rainfall. Overall, our data suggest that the NEE of tropical semideciduous forests is sensitive to temporal variations in surface water availability but that indirect effects of other variables, such as temperature and VPD, are important in controlling CO2 gain and loss. Such interactions will be important for the future NEE under warmer and drier conditions that are anticipated with anthropogenic climate change.

Feeding ecology and activity pattern of black-fronted titi monkeys (Callicebus nigrifrons) in a semideciduous tropical forest of southern Brazil

Most aspects of the ecology and behavior of Callicebus nigrifrons are still unknown. The information available about this species is mainly based on a few studies that also focused on other Callicebus. We examined the feeding behavior and activity pattern of a free-ranging pair of C. nigrifrons between March and November 2007 in an area of semideciduous tropical forest of southeastern Brazil. The study site is located at the southern limit of the Tropical Zone and is characterized by pronounced seasonality. As observed for other Callicebus monkeys, fruits were the most consumed food resource, accounting for 53% of the diet, which was complemented mainly by leaves (16%) but also by invertebrates and flowers (10% of each). A great variety of plant families (28) and species (62) were included in the diet. The titis spent 35% of their time feeding, distributing the remaining time between resting (30%) and traveling (24%). Data presented here indicate that C. nigrifrons prefer high-quality food items (fruit pulp), adding low-quality food items (such as leaves) as the availability of the higher-quality foods decreases. The amount of time spent traveling and resting did not change between seasons, but the time invested in feeding increased during the lean period. The activity pattern was not related to fruit availability, but in months with lower temperatures, monkeys spent more time feeding. We suggest that the feeding ecology and activity pattern of C. nigrifrons reflect adaptations related to annual fluctuations in food availability and temperature, respectively.

Additive partitioning of Phyllostomid bat richness at fine and coarse spatial and temporal scales in Yucatan, Mexico

Neotropical bats exhibit great diversity in terms of resource use, so their species richness can vary both spatially and temporally over fine and coarse scales. In this paper we analyze the relative contribution of the alpha (α) and beta (β) components of bat species richness at different spatial and temporal scales in deciduous and semideciduous tropical forests in Yucatan, Mexico. We used different levels of the spatial (understory and subcanopy height, site, and vegetation type) and temporal (sampling period within a night, sampling night, and season) dimensions. For the spatial dimension, we found that the finer level (α) accounted for more than 50% of total richness and was higher (72% of total richness) within the semideciduous tropical forest. Although lower than for α, the percentage contribution of β among sites and β between vegetation types was higher than expected by chance. For the temporal dimension, α contribution was lower than 25% of total richness in all cases, while β at different time scales had a great influence on bat species richness. Our results indicate that the species composition of bat assemblages is dynamic in space and time. Thus, a proper assessment of diversity requires the inclusion of a variety of spatial and temporal scales in sampling designs.

Pollen distribution along climatic and biogeographic gradients in northern Central America

Environmental reconstructions based on fossil pollen rely on the understanding of modern pollen distribution along climatic and biogeographic gradients. This study analyses the modern pollen spectra of Central America using three basic approaches: (1) the evaluation of using modern pollen spectra to differentiate the main vegetation types of the region, (2) the usage of non-linear regression to predict individual pollen abundances as a function of climate, and (3) the construction of pollen—climate transfer functions. Standard pollen analysis was carried out on mud—water interface samples from 81 lakes in the Yucatan Peninsula and adjacent mountains of Guatemala and Mexico. Detrended correspondence and cluster analyses were used to evaluate the biogeographic patterns revealed by this modern pollen data set. Non-parametric locally weighted scatterplot smoothing (LOESS) regression was used to construct pollen—climate functional relationships. Five modern vegetation types were clearly identifiable through their associated pollen spectra: Pinus forest, Quercus forest, mountain mesophyllous forest, tropical rainforest, and tropical seasonal forest. The last group includes three subcategories (evergreen seasonal, tropical semi-deciduous, and tropical deciduous forests), which were not separable via this analysis. Precipitation and temperature trends were consistent and robust for at least 28 and 30 taxa, respectively, in the LOESS regression. While floristic patterns driven by temperature were clearly reflected by the pollen spectra, those driven by precipitation were less sharply defined. Nevertheless, pollen data from the study area offered good resolution to identify broad biogeographic patterns. Furthermore, individual taxa showed high predictability along precipitation and temperature gradients, allowing the theoretical construction of pollen—climate transfer functions. This study provided valuable tools for the interpretation of fossil pollen sequences from Central America.

Habitat use and local harvesting practices of the Orange-fronted Parakeet (Aratinga canicularis) in western Mexico

Orange-fronted Parakeets Aratinga canicularis are widespread and common across their range. However, the ecology and habitat use are scarcely known. Observations of the nest site characteristics, diet, flock size, habitat movements, and local harvesting practices are reported in this study for Colima, Mexico, a site where the species occurs year-round. Characteristics of termitaria nest sites in deciduous oak and tropical semi-deciduous forests were compared. Nesting site selection did not differ between vegetation types, but some preference for higher and larger termitaria is suggested. Availability of suitable nesting sites is apparently not a limiting factor. Anecdotal reports from the local people and empirical observations of eggs and hatchlings by the author suggest a three-month extension of the breeding period to what is reported in the literature. A. canicularis was observed foraging on 25 plant species. Flock size and activity increased during the rainy season, and were reduced during the beginning of the dry season. Observations and movement in semi-deciduous vegetation were common throughout the study, coinciding with the presence of constant although scattered fruit availability. People in the community see the harvesting and selling of parakeets as an additional source of income, in particular during the dry season when agricultural-related income activities are at their minimum. However, the associated mortality and nest-site destruction may pose a threat to the species in this region.

Avifauna de sitios asociados a la selva tropical en la depresión central de Chiapas, México.

Se realizó una descripción de la composición y estructura de la avifauna de sitios asociados a la selva tropical en la Depresión Central de Chiapas, de 2003 a 2004. La riqueza avifaunística en el área de estudio fue de 364 especies considerando el trabajo de campo y los registros previos provenientes de literatura y de especímenes depositados en colecciones. Las familias con mayor riqueza de especies fueron Tyrannidae, Parulidae, Icteridae y Trochilidae. El componente estacional de las especies indica que el 68% son residentes y el 32% restante son migratorias. En cuanto a su abundancia, la mayoría de las especies son consideradas como raras (34%), mientras que las especies comunes y abundantes constituyen el 11% y 3% del total, respectivamente. La selva baja caducifolia registró el mayor número de especies (226), seguida por la vegetación secundaria (163) y la selva mediana subperennifolia (122). De las especies registradas, 136 son registros adicionales para la región de estudio y 56 para el Parque Nacional Cañón del Sumidero. La avifauna registrada incluye el 45% de la avifauna estatal, lo que destaca la relevancia de esta región y una urgente necesidad de establecer estrategias de manejo para su conservación y protección. La cantidad de especies incrementadas y la falta de información en la región sugieren la necesidad de inventarios locales y regionales para un conocimiento más preciso sobre la distribución de las especies

Foliar mycobiota of Coussapoa floccosa, a highly threatened tree of the Brazilian Atlantic forest

We studied the foliicolous mycobiota associated with Coussapoa floccosa. This is a tree belonging to the Cecropiaceae, endemic to the Brazilian tropical seasonal semideciduous montane forest. It is listed as an endangered species because of habitat destruction. Until now no fungus has been recorded in association with this plant species. This paper describes six foliicolous fungi associated with this plant that were collected during a survey of the mycobiota occurring in a locality where a small population of C. floccosa was discovered. All fungi described here are new to science, namely Dennisiella coussapoae, Mycosphaerella coussapoae, Pseudoallosoma nervisequens (which also represents a newly proposed genus), Pseudocercospora coussapoae, Pseudocercospora atrofuliginosa and Tripospermum acrobaticum. The high proportion of taxonomic novelties revealed in this study reflects the general lack of mycological information for forest ecosystems in Brazil and also indicates that vulnerable plant species such as C. floccosa may harbor unique mycobiota. Such mycobiota may depend on their nearly extinct hosts and consequently can be equally endangered with extinction and therefore also deserve consideration for in situ and ex situ conservation.

Do disturbance and productivity influence evenness of seedling, sapling and adult tree species across a semi‐deciduous tropical forest landscape?

Disturbance and productivity may influence and alter community structure by affecting the partitioning of resources among species. Here, we examined how evenness in the relative abundance of growth stages (seedlings, saplings and adults) of woody species is related to measures of productivity (i.e. total diameter breast high (dbh) and tree volume) and aspects of human disturbance (i.e. number of tree stumps, area covered by charcoal making holes and trail length) in a bamboo‐deciduous forest, northeastern of Thailand. Our results using stepwise multiple regressions showed that productivity (total dbh) explained a significant part of the variation in evenness only at the adult stage where evenness decreased with productivity. We found a decreased evenness of saplings with the area covered by charcoal making holes. Evenness of seedlings was not related to productivity or human disturbance variables and other environmental variables contribute more to explain the variation in evenness at this stage. Evenness was correlated consistently between the growth stages but the strength of relationships diminishes across the stages. Our results suggest that high productivity and human disturbance may facilitate competitive dominant species, affecting evenness in woody communities.

The Endangered yellow-headed parrotAmazona oratrixalong the Pacific coast of Mexico

AbstractThe yellow-headed parrotAmazona oratrixis categorized as Endangered on the IUCN Red List but little is known about its distribution, particularly along the Pacific coast of Mexico. We used ecological niche models, with presence records from museum collections and historical sightings, overlain on vegetation maps, to predict the historical range of the yellow-headed parrot along the Pacific coast of Mexico. We compared this with the current range of the species, estimated with ecological niche models using presence–absence data from surveys during 2003–2008. We estimate that the range of the yellow-headed parrot along Mexico’s Pacific coast has contracted by 79%. The current range may now cover only 18,957 km2, in three main areas. At one of these, a small isolated area on the coast of Jalisco, the species may be vulnerable to extirpation or genetic endogamy. There is a lack of conserved tropical semi-deciduous forest, which provides optimal habitat for reproduction of this parrot, within the current range of the species. Only the south, along the coast of Oaxaca, has extensive areas of this habitat. There are only three, small, protected areas within the species’ current range. Conservation strategies need to be implemented to restore connectivity between the three main areas of the current range of the yellow-headed parrot on the Pacific coast of Mexico.