Lowland Dry Forest Research Articles

Gum and resin bearing dryland forests of Somali region, Southeastern Ethiopia: Diversity, structure and spatial distribution

Despite its ecological and socio-economic contributions, the lowland dry forests of Ethiopia have been experiencing severe deforestation and degradation challenges. It is, therefore, crucial to assess the status of the dry forest resources to formulate an appropriate management strategy and its sustainable utilization. This study was formulated to determine spatial distribution, species composition, structure, and regeneration of the gum and resin species bearing dry forests in the Somali regional state of Ethiopia. The recent Sentinel-2A image was procured and used to classify the area, using a supervised Random Forest Algorithm, into different land covers and vegetation types. Inside the two key vegetation types (Acacia dominated woodland and Mixed woodland), forest inventory was conducted by establishing 30 m x 30 m size quadratic sample plots. The results revealed that the study area was divided into settlement (0.2%), bare land (6.0%), undifferentiated forest (0.5%), acacia woodland (36.3%), mixed woodland (54.1%) and scrubland (2.9%). Thirty-four woody species were identified and recorded with a Shannon diversity of 3.03. The population structure showed a lack of sufficient natural regeneration. It is, therefore, imperative to say that the forest containing the gum and resin-bearing species is not replacing itself. On the other hand, the forest has the potential to produce Oleo-gum resin in various kinds and amounts. Thus, implementing appropriate restoration measures is urgent to enhance natural regeneration. Moreover, formulating sustainable utilization while creating product market of gum and resins are important considerations for the future development of the sector. Int. J. Agril. Res. Innov. Tech. 13(2): 6-13, Dec 2023

Mexico’s Forest Diversity: Common Tree Species and Proposed Forest-Vegetation Provinces

We report a relatively rare study of a national forest inventory in a megadiverse country with the systematic collection of herbarium specimens. The taxonomic identification of 22,659 herbarium collections from 6942 sites of Mexico’s national forest inventory resulted in 1464 native tree species (approximately half of Mexico’s estimated total), in 470 genera and 117 plant families. We compared visual tree-species identifications in the field by hired crews, with much more rigorous identification of submitted (mostly sterile) herbarium specimens by experienced taxonomists and specialists at the National Herbarium: for 40% of the 22,659 collections, the identification of species names from the field was confirmed, for 32% it was corrected at the herbarium, and 27% had been sent without any identification. The most commonly collected plant families were Fagaceae (oak family, 21.7% of all collections), Fabaceae (legumes, 17.7%), and Pinaceae (pine family, 13.3%). The most commonly collected tree species in six major forest-vegetation types were Pinus leiophylla in “coniferous forest”, Quercus magnoliifolia in “highland broadleaf forest”, Liquidambar styraciflua in “mountainous cloud forest”, Bursera simaruba in “lowland evergreen forest”, Lysiloma divaricatum in “lowland dry forest”, and Parkinsonia microphylla in “xerophilous scrub”. We overlapped the six major forest-vegetation types with Mexico’s 15 mainland floristic provinces, as circumscribed by Rzedowski. This resulted in 75 so-called forest-vegetation provinces, of which 35 had at least 20 collection sites. The similarity of species composition among these 35 forest-vegetation provinces was only 17–34% with the Jaccard community index, and 15–42% with the Morisita-Horn community index. The number of physically undetected species was estimated statistically for the 35 forest-vegetation provinces, which indicates that there are forest-vegetation provinces, where the number of species could be up to 8.8-fold higher than those detected in the present work. Finally, we suggest a method to distribute sites optimally among the country in future forest inventories, such as to minimize the average area represented by the sites in each forest-vegetation province.

Recovery of Carbon and Vegetation Diversity 23 Years after Fire in a Tropical Dryland Forest of Indonesia

Understanding the recovery rate of forest carbon stocks and biodiversity after disturbance, including fire, is vital for developing effective climate-change-mitigation policies and actions. In this study, live and dead carbon stocks aboveground, belowground, and in the soil to a 30 cm depth, as well as tree and shrub species diversity, were measured in a tropical lowland dry forest, 23 years after a fire in 1998, for comparison with adjacent unburned reference forests. The results showed that 23 years since the fire was insufficient, in this case, to recover live forest carbon and plant species diversity, to the level of the reference forests. The total carbon stock, in the recovering 23-year-old forest, was 199 Mg C ha−1 or about 90% of the unburned forest (220 Mg C ha−1), mainly due to the contribution of coarse woody debris and an increase in the 5–10 cm soil horizon’s organic carbon, in the burned forest. The carbon held in the live biomass of the recovering forest (79 Mg C ha−1) was just over half the 146 Mg C ha−1 of the reference forest. Based on a biomass mean annual increment of 6.24 ± 1.59 Mg ha−1 yr−1, about 46 ± 17 years would be required for the aboveground live biomass to recover to equivalence with the reference forest. In total, 176 plant species were recorded in the 23-year post-fire forest, compared with 216 in the unburned reference forest. The pioneer species Macaranga gigantea dominated in the 23-year post-fire forest, which was yet to regain the similar stand structural and compositional elements as those found in the adjacent unburned reference forest.

Multi-Stemmed Habit in Trees Contributes Climate Resilience in Tropical Dry Forest

Understanding how environmental adaptations mediate plant and ecosystem responses becomes increasingly important under accelerating global environmental change. Multi-stemmed trees, for example, differ in form and function from single-stemmed trees and may possess physiological advantages that allow for persistence during stressful climatic events such as extended drought. Following the worst drought in Hawaii in a century, we examined patterns of stem abundance and turnover in a Hawaiian lowland dry forest (LDF) and a montane wet forest (MWF) to investigate how multi-stemmed trees might influence site persistence, and how stem abundance and turnover relate to key functional traits. We found stem abundance and multi-stemmed trees to be an important component for climate resilience within the LDF. The LDF had higher relative abundance of multi-stemmed trees, stem abundance, and mean stem abundance compared to a reference MWF. Within the LDF, multi-stemmed trees had higher relative stem abundance (i.e., percent composition of stems to the total number of stems in the LDF) and higher estimated aboveground carbon than single-stemmed trees. Stem abundance varied among species and tree size classes. Stem turnover (i.e., change in stem abundance between five-year censuses) varied among species and tree size classes and species mean stem turnover was correlated with mean species stem abundance per tree. At the plot level, stem abundance per tree is also a predictor of survival, though mortality did not differ between multiple- and single-stemmed trees. Lastly, species with higher mean stem abundance per tree tended to have traits associated with a higher light-saturated photosynthetic rate, suggesting greater productivity in periods with higher water supply. Identifying the traits that allow species and forest communities to persist in dry environments or respond to disturbance is useful for forecasting ecological climate resilience or potential for restoration in tropical dry forests.

Shifting Limitations to Restoration across Dryland Ecosystems in Hawaiʻi

Hawaiian dryland ecosystems are important for global biodiversity conservation and contain numerous species threatened with extinction. Over the past century, wildfire frequency and size have increased dramatically because of invasion by fire-promoting non-native invasive species, greatly threatening these ecosystems. Native species restoration is a tool that can disrupt the cycle of increased fire and invasion in lowland dry forest communities, but restoration prescriptions have not been studied systematically in other dryland plant communities. We examined the restoration of three Hawaiian dryland plant communities (a high-productivity Diospyros sandwicensis and Metrosideros polymorpha lowland dry forest (HP), a moderate-productivity Myoporum sandwicense and Sophora chrysophylla dry forest/woodland (MP), and a low-productivity Dodonaea viscosa shrubland (LP)), using a community-assembly framework to understand the abiotic and biotic constraints to species establishment and growth in each community. Because active restoration methods are often needed, at both high and low levels of productivity, we also examined restoration treatments and outcomes across the three sites, which spanned a gradient of rainfall and substrate age. At each site, we used the same factorial field experiment with three factors: habitat quality (high or low), weed control (yes or no), and species addition (none, seeding, or outplanting). Outplants (cohort 1) and seeds were added in the winter of 2009–2010, and outplants were added again in March 2011 (cohort 2). Dispersal limitation was apparent at the LP and HP sites, but was not observed in the MP site, which had, overall, greater native diversity and abundance. Outplant survival was greater in high-quality habitats at the HP site, likely due to reduced abiotic stress. Invasive species were found in greater abundance in certain types of microsites at the LP and MP sites, suggesting that shade or topography can be used to plan restoration and weed-control activities. Overall, active restoration methods improved restoration outcomes at the high- and low-productivity sites, and less so at the moderately productive site. Weed removal and outplanting were effective restoration prescriptions at the LP and HP sites, and habitat quality could also be used to increase survival at the HP site. Active restoration could be a lower priority for moderately invaded, moderate-productivity communities, which have the capability to maintain a native ecosystem state.

Vampyrum spectrum (Phyllostomidae) movement and prey revealed by radio-telemetry and DNA metabarcoding.

The spectral bat (Vampyrum spectrum), the largest bat species in the Americas, is considered Near Threatened by the International Union for Conservation of Nature and is listed as a species of special concern or endangered in several countries throughout its range. Although the species is known as carnivorous, data on basic ecology, including habitat selection and primary diet items, are limited owing to its relative rarity and difficulty in capturing the species. Leveraging advances in DNA metabarcoding and using radio-telemetry, we present novel information on the diet and movement of V. spectrum based on locations of a radio-collared individual and fecal samples collected from its communal roost (three individuals) in the Lowland Dry Forest of southern Nicaragua. Using a non-invasive approach, we explored the diet of the species with genetic markers designed to capture a range of arthropods and vertebrate targets from fecal samples. We identified 27 species of vertebrate prey which included birds, rodents, and other bat species. Our evidence suggested that V. spectrum can forage on a variety of species, from those associated with mature forests to forest edge-dwellers. Characteristics of the roost and our telemetry data underscore the importance of large trees for roosting in mature forest patches for the species. These data can inform conservation efforts for preserving both the habitat and the prey items in remnants of mature forest required by Vampyrum spectrum to survive in landscape mosaics.

Diversité des Arthropodes de sous-bois des forêts sèches de Madagascar

Diversity of understory arthropods in the dry forests of Madagascar. The arthropods of Madagascar are among the most poorly known animal groups on the island. The principal objective of this study was to determine the diversity of this group at three different localities in lowland dry forests of western Madagascar. The three sites, all inventoried during the dry season in 2017, include: the Ankarafantsika National Park (16°18’S, annual rainfall: 867 mm) in the northwest; the forest of the Centre National de Formation, d’Études et de Recherches en Environnement et Forestier (CNFEREF) at Kirindy (20°04’S, annual rainfall: 555 mm) in the central west; and the Tsimanampesotse National Park (24°01’S, annual rainfall: 334 mm) in the extreme southwest. Malaise and pit-fall traps were used to capture arthropods and 24 orders belonging to 133 families were identified. The community at Ankarafantsika was the most diverse with 19 orders and 89 families with a more balanced taxonomic representation, while Tsimanampesotse had 18 orders and 69 families and Kirindy CNFEREF had 17 orders and 70 families. Calculated similarity between the different sites at the family level was relatively high, while that at the order level relatively low even given a certain level of homogeneity was noted between the three localities. The composition of arthropods in the dry forests of Madagascar varies according to local conditions, which include bioclimatic factors, and the characteristics of the vegetation at the three localities.

Myxomycetes associated with three different types of Neotropical urban landscapes

Urban ecology is a research field gaining momentum due to contextual pressures to study macroecological effects on biodiversity. Herein, we evaluated the occurrence of myxomycetes in three urban Neotropical environments representing different levels of conurbation within different life zones. We used the moist chamber technique set up with ground litter collected by public roads for such evaluation. Results showed that 79% of the 420 moist chambers yielded myxomycetes and the same number of samples generated 570 records. The highest number of records and species were found in the cornurbated widespread city of the premontane moist forest life zone; and fewer records and species were recorded in the two non-conurbated compact cities. The lowest number of records was associated with the lowland dry forest life zone, whereas the lowest number of species was recorded in the desertic context. In general, more records and more species were observed in the outer zones relative to the urban centre but no significant differences were observed in either case. It is unlikely that the life zone characteristics could have primarily determined the results and highly likely played a secondary role. Also, previous geographical analyses in cities have reported no differences in myxomycete abundance or species richness in relation to the central parts of the urban landscape. The results presented herein support the latter idea, but also suggest that the presence of inter-conurbated green spaces and availability of substrates might play a role in the occurrence of sporocarps of myxomycetes in urban environments.

Integrating Economic Value of Environmental Services and Carbon Stock: A Case Study from Bogani Nani Wartabone National Park

As a conservation area, national parks play essential roles in environmental services provision and have the potential to support the REDD+ program. This study aims to estimate appropriate incentives for national parks based on carbon units by integrating the economic value of environmental services and carbon stock provided by the lowland dry forest ecosystem in Bogani Nani Wartabone National Park (BNWNP) consisted of North Sulawesi and Gorontalo areas. Carbon stock was estimated by establishing sample plots, including five carbon pools. While the economic valuation of environmental services includes biodiversity using the market approach, ecotourism using the zonal travel cost method, and water service using simulation water regulation services method and market approach. The total ecosystem carbon stock in BNWNP is estimated at 73.67 Mton. Meanwhile, the estimation of the economic value of environmental services is about IDR 70.57 trillion. Based on these results, the appropriate carbon values are IDR 683,308 and IDR 1,304,238 per ton carbon for the lowland dry forest ecosystem in Gorontalo and North Sulawesi areas. This result indicates that given its essential environmental services, the incentive for protecting national parks may exceed the carbon value used in result-based payment scheme in REDD+ initiatives that have been implemented.

Distribution of Panama\u2019s narrow-range trees: are there hot-spots?

BackgroundTree species with narrow ranges are a conservation concern because heightened extinction risk accompanies their small populations. Assessing risks for these species is challenging, however, especially in tropical flora where their sparse populations seldom appear in traditional plots and inventories. Here, we utilize instead large scale databases that combine tree records from many sources to test whether the narrow-range tree species of Panama are concentrated at certain elevations or in certain provinces. Past investigations have suggested that the Choco region of eastern Panama and the high mountains of western Panama may be potential hotspots of narrow-range tree species.MethodsAll individual records were collected from public databases, and the range size of each tree species found in Panama was estimated as a polygon enclosing all its locations. Species with ranges <20,000 km2 were defined as narrow endemics. We divided Panama into geographic regions and elevation zones and counted the number of individual records and the species richness in each, separating narrow-range species from all other species.ResultsThe proportion of narrow endemics peaked at elevations above 2000 m, reaching 17.2% of the species recorded. At elevation <1500 m across the country, the proportion was 6-11%, except in the dry Pacific region, where it was 1.5%. Wet forests of the Caribbean coast had 8.4% narrow-range species, slightly higher than other regions. The total number of narrow endemics, however, peaked at mid-elevation, not high elevation, because total species richness was highest at mid-elevation.ConclusionsHigh elevation forests of west Panama had higher proportions of narrow endemic trees than low-elevation regions, supporting their hot-spot status, while dry lowland forests had the lowest proportion. This supports the notion that montane forests of Central America should be a conservation focus. However, given generally higher diversity at low- to mid-elevation, lowlands are also important habitats for narrow-range tree species, though conservation efforts here may not protect narrow-range tree species as efficiently.

The presence of Dry Forest Racer, Masticophis mentovarius (Dum&amp;eacute;ril, Bibron &amp;amp; Dum&amp;eacute;ril, 1854) (Squamata, Colubridae), in the Cloud Forest of Monteverde, Costa Rica

Masticophis mentovarius (Dum&amp;eacute;ril, Bibron &amp;amp; Dum&amp;eacute;ril, 1854) occurs at low and moderate elevations in Lowland Dry Forest and Premontane Moist Forest. This species is known in Costa Rica mainly from the dry lowlands of the northwest. Here we report the presence of M. mentovarius at the Tropical Cloud Forest of Monteverde, Costa Rica, at 1275 m a.s.l. The new records provide information on the true limits of the distribution of species and may represent expansion of the species&amp;rsquo; range due to environmental changes caused by global climate change.

Dispersal limitation, soil, and fire affect functional properties of tropical secondary forests on abandoned cattle ranching landscapes

Forest age is a major predictor of secondary forest functional properties and through the chronosequence approach continues to be a principal focus in local, landscape, and regional-scale studies of secondary succession. Recent work has shown that patterns of temporal change in functional properties differ markedly between wet and seasonally dry lowland forests, suggesting that decreasing light and increasing water availability, respectively, are the main drivers of successional change. Meanwhile, however, the potentially marked effects of anthropogenic factors (especially fire), soils, climate, and dispersal limitation on the variation of forest characteristics over landscapes remain poorly understood. We studied the functional properties of seasonally dry secondary forests 5–35 years after pasture abandonment on the Nicoya Peninsula, Costa Rica. We measured 11 functional traits for 63 dominant tree and palm species in 52 plots of 0.12 ha. We used linear regression and variation partitioning to determine the relative importance of soil, climate, site use, fire history, spatial factors, and forest age in the determination of community weighted mean (CWM) trait values. CWM leaf trait and stem trait spectra of the 52 plots were orthogonal in a PCA ordination. Our seasonal forest hypothesis, that forest functional properties become more acquisitive with age as suggested by other authors, was not supported, perhaps because our chronosequence was relatively short. Our fire tolerance hypothesis was that bark thickness, wood specific gravity and resprouting capacity would increase with time of exposure to fires. This hypothesis was not supported for bark thickness. Rather, our results suggest that wood specific gravity and resprouting capacity are better predictors of fire tolerance. Also, our results suggest that >10 years of exposure to fire generates changes in forest fire tolerance strategies from high CWM bark thickness to high wood specific gravity. Finally, we tested our dispersal limitation hypothesis, that spatial variables, expressed as principal coordinates of neighbor matrices (PCNM) eigenfunctions, predict variation in forest functional properties, using variation partitioning analysis with matrices of climate, soil, anthropogenic and spatial variables. The results (overall model R2 = 0.46) indicated that spatial variables, followed by soil (acidity, depth, and extractable Mn), are the best overall predictors of forest functional traits values, supporting this hypothesis. Overall, fire, dispersal limitation and soil characteristics explain the functional properties of these secondary forests, with no effect of age in the 5–35 years range. This indicates a critical need for sampling designs and analytical approaches that take into account all these factors to advance understanding of tropical seasonal forest recovery at the landscape scale.

Effect of environmental gradients on tree distribution in lowland dry evergreen forest, northeastern Thailand

Effect of environmental gradients on tree distribution in lowland dry evergreen forest, northeastern Thailand

Drivers of diversity and altitudinal distribution of chironomids (Diptera: Chironomidae) in the Ecuadorian Andes

Introduction: Chironomids (Diptera: Chironomidae) are the most globally diverse and widely distributed aquatic insects. Despite their prevalence in lotic systems, little is known about the ecology and diversity of tropical species relative to other aquatic insect taxa, particularly at the immature stages. Objective: Characterize chironomid diversity across an elevational gradient in Southwestern Ecuador and water quality parameters associated with their composition. Methods: Samples were collected using a Surber net in forty rivers within four watersheds in the Ecuadorian Andes comprised of montane and dry lowland forest and spanning an elevational gradient of 3 120 m.a.s.l. Various physic chemical variables were measured including oxygen, conductivity, total dissolved solids, temperature, and pH. Results: Generally, environmental variables were strongly correlated with the composition of chironomid communities. Variation in the chriomid communities was most strongly associated with oxygen, conductivity and pH. The presence of Parametriocnemus, Cricotopus f4, Cricotopus sp3., Cricotopus (Isocladius), Oliveiriella, Onconeura, Alotanypus and Pentaneura was associated with lower temperatures, high dissolved oxygen and low conductivity while assemblages of Cricotopus sp., Rheotanytarsus, Tanytarsus, and Chironomus were associated with high conductivity and low concentrations of dissolved oxygen. The RELATE analysis showed that local environmental characteristics are determine the composition of the chironomid community. Conclusions: Similarity among local environmental factors was strongly correlated to similarity among Chironomidae assemblages, especially with variables such as oxygen concentration, pH and conductivity, whose variables are highly correlated to land use and dominant vegetation in the watersheds sampled.

Home Range Estimates for Small Indian Mongooses (Urva auropunctata) in Southwestern Puerto Rico

The small Indian mongoose (Urva auropunctata) is an opportunistic omnivore introduced to sugar producing islands primarily to control rat (Rattus spp.) populations, yet is now considered an invasive pest species on multiple Caribbean islands. Data on home range estimates of mongooses in Puerto Rico and other regions are limited. We fitted 24 mongooses (15 males and nine females) with very high frequency (VHF) radio collars at the Cabo Rojo National Wildlife Refuge in southwestern Puerto Rico and tracked them via radio telemetry for up to six months. The raw mean (SE) minimum convex polygon home range among 24 mongooses was 45.03 (8.30) hectares. The mean (SE) fixed kernel 95% estimate was 38.37 (5.78) hectares, and the 50% core area estimate was 7.89 (1.29) hectares. Our home range estimates are similar to previous estimates in the Caribbean and other islands, but larger than those reported from their native range in India. Our study adds new information to the small body of literature available on mongoose home ranges and is one of the few studies conducted in a lowland dry semi-deciduous forest in southwestern Puerto Rico. Additional research on mongoose home ranges in suburban/rural habitats, as well as in agricultural areas, would provide valuable information for the management of wildlife disease and damage conflicts associated with mongooses in the Caribbean region.

The Flora Diversity of Lasitae Protected Nature Forest and the Nearby Area, District of Barru, South Sulawesi

An expedition to Lasitae Protected Forest in District of Barru, South Sulawesi was undertaken to collect living plants for Pucak Botanic Garden, South Sulawesi. The aims were to investigate the diversity of the plants and as a dedication to the Expedition of the Republic of Indonesia Corridor Sulawesi. Using an explorative method, we collected the plants and recorded all data in the field following the tracks assisted by the field guide. A total of 179 collection-numbers have been collected from this dry lowland forest including the data for the local names. Many potential and valuable plants occur in the forest, 13 plants were highlighted in this paper for its conservation status, the potentiality for various purposes or its uniqueness: Diospyros celebica Bakh. or streak ebony (Ebenaceae), Arenga pinnata (Wurmb.) Merr. (Arecaceae), Phyllanthus lamprophyllus Mull.Arg. (Phyllanthaceae), Cycas rumphii Miq. (Cycadaceae), Lagerstroemia speciosa (L.) Pers. (Lythraceae), Garcinia celebica L. (Clusiaceae), Nervilia aragoana Gaud. (Orchidaceae), Phalaenopsis amabilis (L.) Blume (Orchidaceae), Ophioglossum reticulatum L. (Ophioglossaceae), Tetracera scandens (L.) Merr. (Dilleniaceae), Derris trifoliata Lour., Phytocrene bracteata Wall. (Icacinaceae), and Dioscorea hispida Dennst. Buchanania arborescens (Blume) Blume and Ardisia elliptica Thunb. can easily be found and widely spread.

Litterfall production and associated carbon and nitrogen flux along exclosure chronosequence at Kewet district, central lowland of Ethiopia

BackgroundLitterfall input and associated nutrient flux are critically important in the restoration of soil in degraded landscapes through exclosures. This study was conducted to evaluate the effects of exclosure on seasonal litterfall production and nutrient content, and estimate annual C and N inputs to the soil in an age sequence at Kewet district, central lowland of Ethiopia. Leaf litterfall production was recorded by a 0.25 m2 litter trap from a systematically laid line transects from 5, 15, and 20 years old exclosures and adjacent grazing land.ResultsLeaf litterfall input in the exclosures ranged from 37 g m−2 in January (at the old exclosure) to 7.33 g m−2 (at the young exclosure), and 3 g m−2 in March at the grazing land. Litterfall input showed seasonal variation and peaked in the dry months. Mean monthly leaf litterfall production was significantly (p <0.05) higher (22 g m−2) in the old exclosure than the adjacent grazing land (9 g m−2). Total annual leaf litterfall ranged from 1073 kg ha−1 (grazing land) to 2662 kg ha−1 (old exclosure). There were no significant differences in leaf litterfall nutrients i.e., N, P, K, Ca, and Mg concentrations, except for C. The annual leaf litterfall associated C and N input ranged from 412 (grazing land) to 1025 (old exclosure) and 27 (middle age exclosure) to 68 kg ha−1 (old exclosure), respectively. The positive change recorded in leaf litterfall production and associated C and N return is associated with restoration of vegetation.ConclusionsThrough well-managed area exclosure, leaf litterfall production in the degraded landscapes can reach the level of tropical dry lowland forest in about a decade. Further research on the contribution of dominant tree species in litter production along the age of exclosure is recommended to improve the effectiveness of rehabilitation of degraded lands.

Thermoregulation in the dry forest anole, Norops cupreus

Norops cupreus inhabits lowland dry forests and gallery forests along the Pacific Coast of Central America. We used operative temperature models (OTM) to examine the thermoregulation of this species in Parque Nacional Palo Verde (Costa Rica) by conducting a field study in February 2003. Norops cupreus in Palo Verde appeared to thermoregulate during early morning hours, late evening, and during the afternoon to maintain their body temperature (Tb) < 33°C. Lower capture rates during the midday suggest decreased activity of N. cupreus during this period, perhaps because they actively searched for the coolest environmental temperature (Te). During the rest of the day, N. cupreus appeared to thermoconform, with mean body temperatures tracking minimum available Te. These results are similar to other observations reported for N. cupreus in Central America.

Hummingbird-Plant Network in a Lowland Dry Forest in Yucatan, Mexico

Pollination by animals contributes to the production of nearly 87.5% of the seeds and fruits in the world. Hummingbirds are one of the main groups of pollinating birds in the Americas, and they form pollination networks with the plants they visit. Few hummingbird-plant networks have been studied in tropical dry forest, which is one of the vegetation types most affected by deforestation worldwide. In this study, we describe the characteristics of the core species of a mutualistic hummingbird-plant network in a lowland dry forest located on the Yucatan Peninsula of Mexico. The study lasted a full year, from August 2017 to June 2018. Using point counts and focal observations, we identified three species of hummingbirds that visited eight plant species. The network was highly connected and had three modules—one for each hummingbird species. The core hummingbird species was Chlorostilbon canivetii, and the key plants were Cordia dodecandra, Senna racemosa and Psittacanthus mayanus. This hummingbird-plant network is apparently driven by water availability, which determines plant phenology, which in turn, determines hummingbird activity. In the context of global extinction, the conservation of core species will be critical to maintain the interactions that support all of the species in the network.

Revised taxonomic status of some Mexican and Central American tarantulas (Araneae: Theraphosidae), with transfers from Aphonopelma Pocock, 1901, and a new genus from the Pacific lowlands of Nicaragua and Costa Rica

The type material of several Central American tarantulas (Theraphosidae; Theraphosinae) were re-examined within a broader revision involving the defunct genus EurypelmaKoch, 1850 and the poorly defined AphonopelmaPocock, 1901. Here, we create the new monotypic genus Sandinistagen. nov. for a revised taxon Sandinista lanceolatum (Simon, 1891) comb. nov., which is a small tarantula from the Pacific lowland dry forests of Nicaragua and Costa Rica. It was originally described under Eurypelma and later transferred to Aphonopelma without justification. Based on comparison of type specimens against new material, we emphasise its unusual bulb anatomy to rediagnose it as a new genus with suggested close affinity to AphonopelmaPocock, 1901 (sensu stricto), Sphaerobothria Karsch, 1897, and StichoplastorisRudloff, 1997. We also re-examined the type material of Brachypelma fossorium Valerio, 1980, which is here treated as a junior synonym of S. lanceolatum, syn. nov. We also discuss the Mexican/Central American genus Crassicrus Reichling & West, 1999, into which we transfer another former Eurypelma from the Yucatán. This species was later called Aphonopelma stoicum (Chamberlin, 1925), which we revise as Crassicrus stoicumcomb. nov. and contrast against other described congeners. We also re-evaluate two other specimens later determined as Aphonopelma stoicum by Schmidt & Piepho (1997), including the alleged first female for the species, and consider them as mis-identified congeners. Finally, we provide some discussion on Citharacanthus meermani Reichling & West, 2000 from Belize in the context of Crassicrus, due to similar aspects of their male palpal bulb morphology, highlighting potentially informative aspects.