Higher Species Density Research Articles

New species of Gehyra (Squamata: Gekkonidae) from Papua New Guinea

I describe four new species of Gehyra from New Guinea and immediately adjacent islands. Two of these are giant species that have long been misassigned to either G. vorax or G. membranacruralis; the other two were previously referred to G. oceanica. Each of the new species has a very circumscribed geographic distribution, with one being known from only a single island, a second from a small portion of southeastern New Guinea and immediately adjacent islands, a third from a small archipelago, and the fourth from foothill forest along the northern versant of eastern New Guinea. Three of these species are found only in the Milne Bay Region of southeastern Papua New Guinea, a region previously identified as having a globally high density of narrow-range endemic reptile and amphibian species. These species provide further extension of that pattern by increasing the number of known endemic herpetofaunal species from that small region to 165. Variation in subcaudal shape is taxonomically useful in Gehyra, but its character-state coding must rely on original tails because aberrant development of subcaudals in some regenerated tails could lead to mischaracterization of this feature.

Rock outcrops as interglacial refugia for plants: Ecological evidence from the forest‐steppe transition of Patagonia

AbstractIn the forest‐steppe transition of Patagonia from Argentina, the intense physical variability promotes the occurrence of contrasting vegetation units, among which is the saxicolous meadow developed on rock outcrops. In temperate and tropical regions, these geoforms of highly variable climate and topography, and poor soil development play an ecological and evolutionary role disproportionate to their reduced area. In Aguas Frías (38°46′S, 70°54′W), the range, diversity, density and adaptation of vascular plant species growing in the saxicolous meadow were compared to those of the surrounding steppe, forest and hygrophilous meadow. We hypothesize that rock outcrops exhibit a compositionally and functionally divergent, cold‐adapted flora of a previously more widespread distribution, allowing them to be categorized as refugia for species whose range retreated during the current interglacial. In comparison to the other units, the saxicolous meadow exhibited a small area, low plant cover, high total, native and rare species richness, high density and diversity of species, high richness of unique families and species and an exclusive presence of (rock) ferns. It also presented a high richness of endemic species with more extreme latitudinal and altitudinal distribution, particularly >46° S and >3000 m a.s.l. The similarity of species between the saxicolous meadow and the other units was low. Chamaephytes and nanophanerophytes were dominants, hemicryptophytes and geophytes were infrequent and mesophanerophytes and therophytes were absent. Equivalent results in terms of area of rock outcrops, and origin, strategy, composition, diversity and range of species were found in different regions. The biological and physical attributes would allow these outcrops to be characterized as reduced habitats of high diversity which could be acting as refugia for cold‐adapted plants. Conservation actions must prevent and mitigate the effects of fire, biological invasion and cattle grazing that represent the current threats to this ecosystem.

Regionwide and Nationwide Floristic Richness Reveal Vascular Plant Diversity in Central Asia.

Central Asia (CA) is located in the interior of the Eurasian continent and consists of five countries-Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. It contains the largest concentration of temperate deserts and mountains of CA biodiversity hotspots. However, regionwide floristic diversity is sorely lacking, and nationwide floristic diversity is seriously outdated in this region. Using the data collected by the Mapping Asia Plants (MAP) project, we describe and analyze the diverse floristic characteristics of plant diversity in CA at both the regional and national levels, including the dominant families and genera, endemic taxa, and floristic similarity. The results allow the compilation of a new checklist of vascular plants in CA, including 9643 taxa (1198 genera within 139 families) and 3409 endemic taxa (414 genera in 66 families). We confirm that there are 5695, 4036, 4542, 3005, and 4222 species of vascular plants within the CA countries, of which 532, 326, 505, 175, and 301 species are endemic taxa in Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan, respectively. The region's biodiversity is notable for its high degree of endemism-up to 35.35%-which contributes to the floristic uniqueness and the irreplaceability of CA. Tajikistan, encompassing the most dominant area of the CA mountains, has the highest species density (3.19/100 km2) and endemism (11.12%) among the five countries. Neighboring countries such as Tajikistan and Uzbekistan, and Kazakhstan and Kyrgyzstan share more species in common, while Turkmenistan has less species overlap with the other four countries. Trends in endemic and total taxa are consistent. This comprehensive inventory is novel, revealing CA's plant diversity in two dimensions and providing a solid foundation for subsequent research that will be beneficial to the transboundary conservation and sustainable use of plant resources in CA.

Can Siphon Hole Morphometrics Be Used for Population Assessments of Intertidal Soft-Shell Clams, Mya arenaria?

Measuring infaunal population dynamics relies on destructive sampling that disturbs sediments and removes animals from their habitat. Establishing effective, non-invasive sampling methods for monitoring infaunal populations can reduce the impact of scientific sampling and facilitate efficient population assessments. Using intertidal soft-shell clams (Mya arenaria L.) in eastern Canada, we explored whether population density and size structure could be estimated from visible siphon holes. Across four sites with varying sediment characteristics and infaunal species assemblages, we predicted the presence of M. arenaria with 78–100% accuracy by visually assessing siphon holes. Smaller holes (< 7.5 mm) were more likely to be misidentified. Siphon hole count was a strong predictor of actual clam count and biomass at most sites, except the site with wet muddy sediment and high densities of other infaunal species. Siphon hole length was positively related to clam shell length and wet weight at all sites; however, relationships typically had low R2 values (< 0.35). Ultimately, visual assessments of intertidal siphon holes can be effective for estimating M. arenaria densities and size structure in some habitats. Testing the application of this method to other habitats and species is warranted.

Indeks Ekologi dan Kepadatan Komunitas Cerithidea Spp. di Perairan Pengudang dan Dompak

Macrozoobenthos is a group of benthic organisms measuring more than 1 mm that plays a crucial role in the process of decomposition and mineralization of organic material in aquatic ecosystems. The purpose of this observation was to determine the ecological index and density of macrozoobenthos in Pengudang and Dompak Waters. This observation was conducted from May 26-27, 2024 in the waters of Pengudang and Dompak using the survey method. Determination of sampling points is done by random sampling of 20 points each line transect. Macrozoobenthos measurements using 1x1m quadrant transect. The results showed that Pengudang waters had a higher species density with an average value of 13 (medium) compared to Dompak with an average of 0.03 (low). The diversity index ranged from 0.36-1.05, with Pengudang showing higher values. The uniformity index in Pengudang was 0.50 (medium), and in Dompak 0.17 (low). The dominance index was higher in Dompak (0.84) than Pengudang (0.40). Water quality parameters showed that temperature, salinity and pH were within safe limits, but TSS values in Dompak exceeded quality standards, indicating higher sedimentation levels.

Deer exclusion is necessary to promote post‐fire herbaceous regeneration in the understorey of a Mediterranean forest

The frequency of severe wildfires is on the rise in the Mediterranean Basin as a result of climate change and land abandonment. Recurrent wildfires may retard or impede ecosystem recovery, frequently requiring the implementation of restoration practices. In that context, a post‐fire deer exclusion experiment was conducted in a Mediterranean mixed forest ecosystem with high population densities of deer species (Fallow deer and Red deer). A deer exclusion area was established as a form of restoration intervention to promote post‐fire vegetation recovery. We surveyed plant species during the second and third springs after fire in both deer‐excluded and deer‐allowed areas in order to detect changes in the community. We analyzed the plant species composition, species diversity, and structure of herbaceous and woody plant communities. We also compared the frequency of annual and perennial herb species, functional groups, and post‐fire plant regeneration strategies. The main differences were due to differences between springs rather than of deer‐excluded and deer‐allowed plots. Deer consumed both woody and herbaceous species, favoring the assemblage of herbaceous over woody species. Deer favored the establishment of annual forbs, including unpalatable and/or exotic species, while limiting the abundance of graminoids. Observed deer impacts could have been magnified during the second spring by a drought. Our study demonstrates that deer exclusion can be an effective restoration practice for promoting post‐fire herbaceous regeneration in forests with significant densities of wild ungulates, although seasonal effects may override restoration practice effects.

Observed and future shifts in climate zone of Borneo based on CMIP6 models

Climate change has significantly altered the characteristics of climate zones, posing considerable challenges to ecosystems and biodiversity, particularly in Borneo, known for its high species density per unit area. This study aimed to classify the region into homogeneous climate groups based on long-term average behavior. The most effective parameters from the high-resolution daily gridded Princeton climate datasets spanning 65 years (1950–2014) were utilized, including rainfall, relative humidity (RH), temperatures (Tavg, Tmin, Tmax, and diurnal temperature range (DTR)), along with elevation data at 0.25° resolution. The FCM clustering method outperformed K-Mean and two Ward's hierarchical methods (WardD and WardD2) in classifying Borneo's climate zones based on multi-criteria assessment, exhibiting the lowest average distance (2.172–2.180) and the highest compromise programming index (CPI)-based correlation ranking among cluster averages across all climate parameters. Borneo's climate zones were categorized into four: ‘Wet and cold’ (WC) and ‘Wet’ (W) representing wetter zones, and ‘Wet and hot’ (WH) and ‘Dry and hot’ (DH) representing hotter zones, each with clearly defined boundaries. For future projection, EC-Earth3-Veg ranked first for all climate parameters across 961 grid points, emerging as the top-performing model. The linear scaling (LS) bias-corrected EC-Earth3-Veg model, as shown in the Taylor diagram, closely replicated the observed datasets, facilitating future climate zone reclassification. Improved performance across parameters was evident based on MAE (35.8–94.6%), MSE (57.0–99.5%), NRMSE (42.7–92.1%), PBIAS (100–108%), MD (23.0–85.3%), KGE (21.1–78.1%), and VE (5.1–9.1%), with closer replication of empirical probability distribution function (PDF) curves during the validation period. In the future, Borneo's climate zones will shift notably, with WC elongating southward along the mountainous spine, W forming an enclave over the north-central mountains, WH shifting northward and shrinking inland, and DH expanding northward along the western coast. Under SSP5-8.5, WC is expected to expand by 39% and 11% for the mid- and far-future periods, respectively, while W is set to shrink by 46%. WH is projected to expand by 2% and 8% for the mid- and far-future periods, respectively. Conversely, DH is expected to expand by 43% for the far-future period but shrink by 42% for the mid-future period. This study fills a gap by redefining Borneo's climate zones based on an increased number of effective parameters and projecting future shifts, utilizing advanced clustering methods (FCM) under CMIP6 scenarios. Importantly, it contributes by ranking GCMs using RIMs and CPI across multiple climate parameters, addressing a previous gap in GCM assessment. The study's findings can facilitate cross-border collaboration by providing a shared understanding of climate dynamics and informing joint environmental management and disaster response efforts.

A density surface model describing the habitat of the Critically Endangered Rice’s whale Balaenoptera ricei in the Gulf of Mexico

The newly recognized Rice’s whale Balaenoptera ricei is among the most endangered large whale species in the world and primarily occupies a region near the continental shelf break in the northeastern Gulf of Mexico (GoMex). We analyzed visual line-transect survey data collected throughout the northern GoMex from 2003-2019 and developed spatially explicit density maps using a density surface modeling approach to examine relationships between Rice’s whale density and bathymetric and oceanographic features. We identified water depth, surface chl a concentration, bottom temperature, and bottom salinity as key parameters that define the Rice’s whale habitat. This is consistent with upwelling of cold, high-salinity water along the continental shelf break and seasonal input of high-productivity surface water originating from coastal sources. The dominant circulation patterns in the GoMex, including the presence of Loop Current eddies, lead to increased productivity and likely play a role in maintaining high densities of forage species needed to support Rice’s whales. Extrapolation of the model suggests additional regions in Mexican waters of GoMex that may be suitable for Rice’s whales. This study informs the designation of critical habitat as defined by the US Endangered Species Act and will assist in marine spatial planning activities to avoid additional anthropogenic impacts to Rice’s whales associated with the development of wind energy and aquaculture.

Biodiversity of intertidal mollusks in Surigao City, Philippines

Intertidal zones are crucial ecological interfaces, but there is a lack of comprehensive studies on mollusk communities in Surigao City, Philippines. This research aimed to assess intertidal mollusk profiles, including species density, diversity, evenness, and richness, addressing a knowledge gap in regional mollusk biodiversity. Using a belt transect quadrat method in three sampling areas during 2021, the study employed a descriptive correlation design to investigate relationships between mollusk profiles and seawater physico-chemical parameters (conductivity, dissolved oxygen, pH, salinity, and temperature). In Surigao City's Day-asan, Hikdop Island, and Sibale, 44 gastropod species (19 families) and 11 bivalve species (9 families) were identified. Conidae and Strombidae families dominated. Average seawater parameters were conductivity 51.33, dissolved oxygen 7.45, pH 7.84, salinity 32, and temperature 28.52. Day-asan exhibited the highest species count (49), followed by Hikdop Island (42) and Sibale Island (37). Hikdop Island had the highest species density and evenness, Day-asan had the highest species diversity index, and Sibale Island had the highest species richness. Mollusk profiles showed no significant differences between sampling areas, and a strong negative correlation between pH and species evenness was observed. Surigao City displayed diverse mollusk biodiversity, but a declining trend in diversity indices was noted. This study fills a critical knowledge gap in understanding mollusk community dynamics, providing essential baseline data for future conservation and management strategies in the region, while also shedding light on the impact of environmental factors on intertidal mollusk populations in Surigao City.

Prosopis juliflora invasions and ecological dominance in the sacred groves of Western Haryana, India

The present study was conducted in the sacred groves of Haryana in the semi-arid regions. Prosopis juliflora is one of the most common invasive plant species and has varying degrees of ecological consequences. In Haryana, the vast semi-arid conditions has ideally favoured the invasion of P. juliflora including the sacred groves of the State. Therefore, the present study investigated the population structure of the P. juliflora in the two sacred groves of Haryana i.e. Daya (SG-I) and Kharkada (SG-II) with different degrees of invasion. The impact of the invasive tree on the native flora was also examined by the assessment of different ecological parameters like analytical characteristics of vegetation along with four diversity indices (Shannon-Weiner Index, Simpson Index, Pielou Index and Margalef Index). The results of the study revealed that the sacred grove with low Prosopis invasion (SG-I) had high density and Basal area of native plant species as having significant values for the selected diversity indices and thus is better flourished in comparison to the highly invaded site (SG-II). It can be concluded that the native phytodiversity of the sacred groves of Haryana is in peril due to increasing P. juliflora invasion, thus efficient management strategies are required in this direction.

Influence of different agroforestry production modules on fine roots biomass in the southeastern Amazon

AFS provide important ecosystem services associated with carbon (C) cycling and dynamics and can store C in plant biomass that is often comparable to natural forests. The aim of this study was to quantify and compare the biomass of fine roots (diameter ≤2mm) in different SAF modules (M1, M2, M3, M4, M5) in the southeast of Pará, using two adjacent areas (Urochloa sp. pasture and secondary forest) as a reference. The modules have common crops (banana, manioc, pineapple, corn, cocoa), varying according to the other species intercropped. Each module has an area of 2 ha, the same history and time of implantation, and five 5×5 m plots were randomly installed in each one, where we collected 3 soil samples (0-10 cm) with a volumetric cylinder (196 cm³). In the laboratory, the roots were washed in running water under a 0.5 mm mesh and sorted using tweezers and a caliper. Root biomass was estimated using dry mass (g.m²) and statistical comparisons were made using ANOVA and Tukey's post-test. Forest and pasture showed greater fine root biomass compared to the SAF modules, which were similar to each other (p&lt;0.001; Forest=283.95g.m²; M1=89.01g.m²; M2=65.89g.m²; M3=56.27g.m²; M4=115.96g.m²; M5=81.44g.m²; Pasture =359.25g.m²). In the forest, the high density and diversity of species can increase biomass. The similarity between the SAF modules indicates that the time of implementation (one year) is insufficient to influence root biomass differently, and that the history of the area and soil management influence root biomass, differentiating it from the forest analyzed.

Water quality parameters and population of aquatic insect larvae in Pardi Lake, Gadchiroli District (M.S.) of India

The present research deals with the study on some physicochemical parameters and the population of aquatic insect and insect larvae of Pardi lake, Gadchiroli which was carried out from February 2016 to January 2017. Total 10 genera of aquatic insect larvae recorded during the present piece of investigation, among which Order Diptera is represented by 07 genera and Coleoptera by 03 genera. The Dipteran species are found to be dominant in the lake. The high density of pollution indicator species like Chironomus, Eristalis and Trichoptera larvae indicates the polluted nature of the lake. Thus, keeping in view the importance of the study, the necessary steps should be taken for the conservation and maintenance of lake.

Plasma assisted pulsed laser deposition of WO3 films for thermochromism

Tungsten trioxide (WO3) is one of the extensively investigated transition metal oxides. Its excellent chromogenic properties make WO3 promising for a variety of scientific and technological applications. We report a new method for reactively depositing WO3 films by plasma assisted pulsed laser deposition that combines electron cyclotron resonance microwave discharge and pulsed laser ablation. The plasma formed during film deposition was spectroscopically characterized by optical emission measurement, revealing that the plasma contains high density of reactive gaseous oxygen and tungsten species which are essential for efficiently synthesizing WOx precursors and depositing WO3 films. The structure of the deposited films and the effect of post-deposition thermal annealing on the film structure were characterized by X-ray diffraction and Raman spectroscopy. The as-deposited WO3 film appears amorphous in nature. Annealing resulted in the growth of crystalline grains and the improvement in the crystallinity of monoclinic WO3. Optical properties of the prepared WO3 films were studied by measuring ultraviolet–visible–near infrared transmission spectra. With the increase of annealing temperature, the WO3 films show a continuous change in color, decline in transmittance, red shift in absorption edge, and narrowing in band gap, clearly manifesting the thermochromic features of the deposited WO3 films.

Uncovering the synergy between gold and sodium on ZrO2 for boosting the reverse water gas shift reaction: In-situ spectroscopic investigations

CO2 conversion to CO via the reverse water-gas shift (RWGS) reaction is a promising source of syngas for subsequent synthesis of liquid fuels and chemicals. Herein, we present the synthesis of catalysts containing Au supported on hydroxylated Na-modified ZrO2, with Au amounts ranging from 0.05 to 1 wt%. Systematic investigations reveal the formation of cooperative Au/Na sites at the interface. These sites cooperate synergistically to activate CO2 and generate a high surface density of carboxylate-like species, which serve as highly active intermediates for CO formation. It was found that the RWGS reaction on the catalyst with low Au loading proceeds mainly via a carboxylate pathway, with bidentate formate acting as spectators. At higher Au loading, the bidentate formate pathway contributes somewhat to CO formation alongside the carboxylate pathway. Based on temporal analysis of products, we emphasize the significant roles of H2 spillover and the metal-support interface in the RWGS reaction.

Baboons (Papio spp.) as a potentially underreported source of food loss and kleptoparasitism of cheetah (Acinonyx jubatus) kills

Kleptoparasitism, the theft of food from another individual, is an important interspecific interaction that can have consequences for animal fitness, predation rates, and species' abundance. Similarly, loss of food to fear effects and interspecific interactions can influence energetic costs and consumption rates. Due to their smaller body size and predominantly solitary nature, cheetahs (Acinonyx jubatus) are particularly prone to negative, direct interactions with competing carnivores, and they frequently lose kills to apex predators. However, trophic interactions with other species may have been underreported in the literature. Here, we document anecdotal interactions between cheetah and baboon (Papio spp.) species, across multiple sites in Africa, where baboon troops chased cheetahs off their kills and, in some cases, fed on the remaining carcasses. Given the widespread distribution, and relatively high densities of baboon species across sub-Saharan Africa, we hypothesise that these interactions are likely to be underrepresented in the literature. Since cheetah already experience high levels of competition with apex predators, particularly in South African fenced reserves where competing carnivores are often stocked at densities approaching, or in some cases exceeding, carrying capacity, additional competition and the loss of prey to baboons could further increase predation rates and have implications for reserve management. Baboons are often defensive around large carnivores. As such, interactions with cheetahs are likely to be motivated primarily as a defensive strategy. We encourage further research into food loss, kleptoparasitic behaviour and other competitive interactions between cheetah and Papio species.

Bacterial diversity associated with the Hatay yellow strain silkworm (Bombyx mori L.): Isolation, identification and characterization

The Hatay yellow strain silkworm (Bombyx mori L.), which is in danger of extinction, is one of the most important local cultural heritages of Türkiye. Bacterial pathogens of silkworm are highly destructive and cause mostly acute diseases. The aim of this study was to determine the bacterial diversity and potential pathogenic bacterial species in infected and dead larvae of Hatay yellow race. A total of 16 bacterial isolates from Hatay yellow race were identified according to their morphological, biochemical and molecular characteristics. The bacterial isolates isolated from infected and dead larvae of Hatay yellow race were Staphylococcus sp. (BM-1), Staphylococcus xylosus (BM-5), Staphylococcus succinus (BM-7), Bacillus thuringiensis (BM-8), Bacillus subtilis (BM-9), Bacillus sp. (BM-10), Staphylococcus saprophyticus (BM-16, BM-19), Klebsiella sp. (BM-17), Staphylococcus arlettae (BM-18), Pseudomonas aeruginosa (BM-20), Enterococcus mundtii (BM-21), Pantoea agglomerans (BM-22), Kluyvera intermedia (BM-23), Serratia sp. (BM-24), Mammaliicoccus sciuri (BM-25). The high bacterial density and number of species indicate that Hatay yellow race is highly susceptible to bacterial diseases. Insecticidal activity studies revealed that species belonging to Bacillus and Staphylococcus genera are important pathogens of hybrid silkworm culture and Hatay yellow race.

Zooplankton Community as Indicator of Trophic Status of Lake Tadlac in Los Baños, Laguna, Philippines

Tadlac Lake was heavily used for aquaculture until the late 1990s which resulted in a deterioration of its water quality. Aquaculture operations were banned to rehabilitate the lake after a massive fish kill in 1999. However, no thorough assessment of the rehabilitation's effectiveness has been conducted. In order to assess the success of the rehabilitation efforts, this study evaluated the lake's trophic status through study of its zooplankton community and physical-chemical parameters. Zooplankton samples and physical-chemical parameters were collected once a month from October 2017 to March 2018. Overall, 25 zooplankton species were documented during the sampling period. Rotifera dominated the zooplankton community with a relative density of 46.19%, followed by Copepoda (36.70%) and Cladocera (17.11%). Eutrophic indicator species Brachionus forficula had the highest density among the zooplankton taxa, followed by Keratella tropica and Brachionus havanaensis. Significant variation in zooplankton density was documented over the sampling period (p&lt;0.05). Cluster analysis and analysis of similarities (ANOSIM) showed variation in the zooplankton density across the sampling months. Similarity percentage (SIMPER) revealed that the differences in plankton density were due to the densities of the most abundant taxa. Canonical correspondence analysis (CCA) showed that the zooplankton community was highly influenced by dissolved oxygen, conductivity, pH, biological oxygen demand, and temperature. The high density of the eutrophic indicator zooplankton species and the nutrient concentration of the lake indicated that Tadlac lake was still under eutrophic conditions. Biotic indices further confirmed that the lake was experiencing eutrophic conditions with moderate organic pollution. Therefore, additional approaches are necessary to effectively control the nutrient enrichment in the lake to improve its condition.

Distribution and invasiveness of four non-native species of plants in ecosystems in the Chorokhi delta (SW Georgia)

Chorokhi Delta is known for its high diversity and many habitats, which however are being threatened by invasive plants. Here, the effects of four invasive species of plants, namely Ambrosia artemisiifolia, Sicyos angulatus, Solidago canadensis and Verbena brasiliensis were studied. These species were recorded in the coastal area of the Black Sea and in particular in Georgia for the first time in the first half of the last century and S. angulatus is a very recent arrival. Currently, these species constitute a significant threat to biodiversity at local, national and global levels. These invasive species were monitored from 2021 to 2022. During this period, sites with high densities of the invasive species were identified. For each species, 5 transects were randomly set, and along each of them, 10 plots (1 × 1 m) were surveyed. The density, frequency, coverage and average height of the invasive plants were measured in each plot. These measurements were recorded twice per year for two years (2021–2022). All this information will be used to develop management plans aimed at preventing their further spread or control their abundance. The results indicate that Ambrosia artemisiifolia is the most invasive and widely distributed. Verbena brasiliensis and Sicyos angulatus are also highly competitive species that can seriously affect semi-natural habitats in the Chorokhi Delta and in agricultural land located close to the Delta. Unlike these species, Solidago canadensis is not widely distributed in the area studied. However, its ability to survive in a wide range of habitats and clonal growth indicate that it is potentially a highly dangerous invasive species, which in the future is expected to expand its range and severely affect the semi-natural ecosystems and agricultural land in the Chorokhi Delta. The results of the present study demonstrate the high adaptability of the species studied and their potential for spreading further in the near future.

Biodiversity consequences of long-term active forest restoration in selectively-logged tropical rainforests

Forest restoration figures prominently on climate action plans, both in the public and private sector. Restoration has the potential to enhance forest recovery and carbon storage, yet could cause unanticipated alterations of forest biodiversity and functioning. In particular little is known about the long-lasting effects of active forest restoration. We therefore evaluated the effects of such management on adult trees and seedlings of actively restored forest to comparable areas where forest regenerated naturally. We investigated a forest site in Sabah, Malaysian Borneo that is recovering from selective logging between 1981 and 1991. Some of the area has been left to naturally regenerate, and some areas have been actively restored for production purposes between 1994 and 2004 through climber cutting and enrichment-planting of exclusively indigenous tree species. We hypothesized that active forest restoration affects forest diversity and composition negatively (i.e., reduction in diversity and presence of pioneer species), and that the silvicultural interventions had long-lasting effects (i.e., higher density of species that were planted, fewer climbers).Surprisingly, our findings suggest that active forest restoration promoted the recovery of adult tree species diversity, expressed as Shannon Diversity Index, and in particular promoted rare species. In actively restored plots, the number of adult individuals of tree species that were planted was enhanced, and the density of liana seedlings was reduced, demonstrating that these silvicultural interventions were effective and had long-lasting effects on the forest structure. Nevertheless, we could not detect differences in the number of seedlings of species that were planted nor in the density of adult lianas between actively restored and naturally regenerating forest sites. We also did not find differences in the species diversity of seedlings, but we observed a compositional shift in the species community for seedlings that were younger than one year. Furthermore, we did not detect a difference between actively restored and naturally regenerating forest plots in the abundance of the present tree guilds (i.e., pioneer or late-succession species) for neither adult trees nor seedlings, as all of our forest plots were dominated by late-succession species.Our results show that active forest restoration can promote species diversity and highlight that active forest restoration focusing on biomass production does not need to adversely affect biodiversity. This work emphasizes the potential of active forest restoration on biodiversity and potentially other key ecosystem functions which are needed to be restored in order to mitigate climate change and the current ecological crisis.

Detecting functional rarity in a hyperdiverse Amazonian dung beetle assemblage

The functional space of an ecological community is not evenly filled by its species. Instead, it is usually divided into areas of high species density, where species with common combinations of functional traits are grouped into species rich clusters, while lower density areas are filled with species poor clusters or isolated species with uncommon or unique combinations of traits. Species whose functional traits differ from those of the rest of the community are expected to play distinct ecological roles and over-contribute to ecosystem functionality. Sampling methods used to characterize arthropod assemblages usually target subsets of the community and filter species based on their functional traits, reducing the probability of detecting species with uncommon combinations of functional traits. Consideration of these species is particularly important for characterizing the functional structure and resilience of ecological communities inhabiting threatened ecosystems such as lowland Amazonian rainforests, in which dung beetles play multiple ecological roles and are commonly used as ecological indicators. In this study, we characterize the functional structure of a diverse Amazonian dung beetle assemblage using five different sampling methods (dung- and carrion-baited pitfalls, dung-baited aerial traps, flight interception traps, and visual transects) and 18 different functional traits. Our main objective is to assess the suitability of these methods for the detection of the functional volume of the assemblage and of species with uncommon or unique combinations of functional traits that are expected to support vulnerable ecosystem functions. We found that, although dung-baited pitfalls (DPF) detected the highest species richness and proportion of the functional volume, they did not detect 30 species out of 103 and over 20% of the functional volume of the assemblage. The additional sampling methods captured more species with uncommon combinations of functional traits than expected by chance, some of which were trophic specialists not attracted to DPFs. The use of complementary sampling methods resulted in a better characterization of the functional structure of dung beetle communities inhabiting both terra firme and floodplain Amazonian rainforests and revealed functional resilience and rare species playing ecological roles overlooked by DPFs. The consideration of these species is of great importance given the threats that tropical rainforests face worldwide.