Native Species Diversity Research Articles

The diversity of native tree species from Bung Jagoi community forests, Bau, Sarawak and their potential for reforestation

ABSTRACT The study focuses on the diversity of native species from which can be selected potential species in Bung Jagoi community forests for reforestation. Multi-aged regeneration survey using nested plot design was carried out on four types of forest in Bung Jagoi community forests. The findings indicate that the intact and undisturbed primary forests are more diverse and hold a number of species with higher importance value than the disturbed forests. Bung Jagoi community forests also have abundant potential native species for reforestation.

Rare, common, alien and native species follow different rules in an understory plant community.

Biological invasions are a leading threat to biodiversity globally. Increasingly, ecosystems experience multiple introductions, which can have significant effects on patterns of diversity. The way these communities assemble will depend partly on whether rare and common alien species respond to environmental predictors in the same manner as rare and common native species, but this is not well understood. To examine this question across four national parks in south‐eastern Australia, we sampled the understory plant community of eucalypt‐dominated dry forest subject to multiple plant introductions. The drivers of diversity and turnover in alien and native species of contrasting frequency of occurrence (low, intermediate, and high) were each tested individually. We found alien species diversity and turnover were both strongly associated with abiotic conditions (e.g., soil pH), while distance had little influence because of the greater extent of occurrence and more homogeneous composition of common aliens. In contrast, native species diversity was not associated with abiotic conditions and their turnover was as strongly influenced by distance as by abiotic conditions. In both alien and native species, however, the most important predictors of turnover changed with frequency of occurrence. Although local coexistence appears to be facilitated by life history trade‐offs, species richness of aliens and natives was negatively correlated and native species might face greater competition in areas with more neutral soils (e.g., pH > ~5.5) where alien richness and relative frequency were both highest. We conclude that diversity and turnover in the generally more widespread alien species are mainly driven by species sorting along an environmental gradient associated with pH and nutrient availability, whereas turnover of native species is driven by more neutral processes associated with dispersal limitation. We show alien and native plant species respond to different environmental factors, as do rare and common species within each component.

Urbanization increases floral specialization of pollinators.

Understanding how urbanization alters functional interactions among pollinators and plants is critically important given increasing anthropogenic land use and declines in pollinator populations. Pollinators often exhibit short‐term specialization and visit plants of the same species during one foraging trip. This facilitates plant receipt of conspecific pollen—pollen on a pollinator that is the same species as the plant on which the pollinator was foraging. Conspecific pollen receipt facilitates plant reproductive success and is thus important to plant and pollinator persistence. We investigated how urbanization affects short‐term specialization of insect pollinators by examining pollen loads on insects’ bodies and identifying the number and species of pollen grains on insects caught in urban habitat fragments and natural areas. We assessed possible drivers of differences between urban and natural areas, including frequency dependence in foraging, species richness and diversity of the plant and pollinator communities, floral abundance, and the presence of invasive plant species. Pollinators were more specialized in urban fragments than in natural areas, despite no differences in the species richness of plant communities across site types. These differences were likely driven by higher specialization of common pollinators, which were more abundant in urban sites. In addition, pollinators preferred to forage on invasive plants at urban sites and native plants at natural sites. Our findings reveal indirect effects of urbanization on pollinator fidelity to individual plant species and have implications for the maintenance of plant species diversity in small habitat fragments. Higher preference of pollinators for invasive plants at urban sites suggests that native species may receive fewer visits by pollinators. Therefore, native plant species diversity may decline in urban sites without continued augmentation of urban flora or removal of invasive species.

Predicted range shifts of invasive giant hogweed (Heracleum mantegazzianum) in Europe

Heracleum mantegazzianum Sommier & Levier (Giant hogweed) has spread across Europe after its introduction as an ornamental from the native range in the Western Greater Caucasus. In addition to its invasive capability, H. mantegazzianum reduces the alpha diversity of native species in the non-native range and can cause second-degree burns when its phytotoxic sap contacts the skin upon exposure to sunlight. Previous studies on H. mantegazzianum distribution focused on individual countries, therefore we know little about the potential shift of the species distribution under changing climate at the continental scale. To fill that gap in the current knowledge, we aimed to (i) identify the most important climatic factors for the distribution of H. mantegazzianum in Europe, (ii) recognize areas that will be suitable and unsuitable for future climate scenarios to prioritize management action. Our study showed that the mean temperature of the coldest quarter (bio11) and temperature annual range (bio7) were the most important bioclimatic variables predicting the suitable habitat of the species in Europe. For all scenarios, we found that the majority of the range changes expected by 2100 will occur as early as 2041. We predicted an overall decrease in climatically suitable area for H. mantegazzianum under climate change with over three quarters (i.e. 94%) of the suitable area reduced under the Shared Socioeconomic Pathway (SSP) 585 in 2100. However, under the same scenario, climate conditions will likely favour the expansion (i.e. 20%) of H. mantegazzianum in northern Europe. The results from the present study will help in developing a climate change-integrated management strategy, most especially in northern Europe where range expansion is predicted.

Modelling avocado-driven deforestation in Michoacán, Mexico

Abstract As demand for avocado climbs, avocado production in Michoacán - Mexico’s biggest avocado growing region - expands into new places. We use a spatial probit model to project the geographic distribution of likely future avocado expansion and analyze those results to determine (1) threats to specific forest types and (2) how the distribution of avocado is shifting spatially under current and future climate scenarios. Our results suggest that avocado expansion in Michoacán is strongly driven by distance to existing agriculture, roads, and localities, as well as the dwindling availability of Andosol soils. As future expansion ensues, it presents risk of forest loss across various forest types, with pine-oak forest, mesophilic montane forest, and oyamel fir forest being of particular concern. Moreover, our results suggest that avocado production will occupy wider ranges in terms of temperature, precipitation, slope steepness and soil. The model predicts that climate change will alter the spatial distribution of avocado plantings, expanding into forest types at lower and at higher elevations. Forest loss threatens ecosystem degradation, and a wider avocado crop production footprint could lead to orchard establishment into dwindling forests that host a high diversity of native oaks and charismatic species, including the monarch butterfly.

Biochar Rescues Native Trees in the Biodiversity Hotspot of Mauritius

Many tropical invasive species have allelopathic effects that contribute to their success in native plant communities. Pyrolyzed biomass (“biochar”) can sorb toxic compounds, including allelochemicals produced by invasive plants, potentially reducing their inhibitory effects on native species. Strawberry guava (Psidium cattleianum) is among the most important allelopathic invasive species on tropical islands and recognized as the most serious threat among invasive species in the global biodiversity hotspot of Mauritius. We investigated the effects of additions of locally produced biochar on native tree species in a field experiment conducted in areas invaded by strawberry guava within Mauritius’ largest national park. Growth and survivorship of native tree species were monitored over 2.5 years in plots subjected to four treatments: non-weeded, weeded, weeded + 25 t/ha biochar, and weeded + 50 t/ha biochar. Native tree growth and survivorship were strongly suppressed by strawberry guava. Biochar treatments dramatically increased native tree performance, with more than a doubling in growth, and substantially increased native tree survivorship and species diversity, while suppressing strawberry guava regeneration, consistent with growth-promoting properties and sorption of allelochemicals. We conclude that biochars, including “sustainable biochars” produced from locally accessible biomass using low-tech pyrolysis systems, have considerable potential to counteract effects of allelopathic invaders and increase the capacity for native species regeneration in tropical island ecosystems.

Stingless bee resources during reforestation of the Atlantic domain of Rio De Janeiro city, Brazil

Extensive farms were developed from the first settlements in the city of Rio de Janeiro. The scarcity of water year after year currently necessitates the reforestation of degraded areas to protect the remaining forestlands and water resources, mainly on hillsides. Native species of plants and stingless bees were introduced, with the main intention of pollination intensification and seed production to grow new shrubs and trees. These reforested areas produced honey and bee pot-pollen. The present study elucidated the pollination dynamics in three areas under reforestation (Serra da Posse area, Morro da Formiga area, and Serra dos Pretos Forros area) considering three native bee species (Nannotrigona testaceicornes, Tetragonisca angustula and Melipona quadrifasciata anthidioides) and pollen analysis of bee products. For sample processing, neither the acetolysis methodology, nor staining was applied. Paired honey and pollen samples were considered, and in addition anemophilous and exotic pollen grains, as well as structured elements. It is suggested to intensify the planting of native trees and shrubs, such as Arecaceae, Mimosaceae, Myrtaceae, Alchornea, Anadenanthera, Piptadenia and Schizolobium, thus allowing the establishment of a diversity of parasitic Loranthaceae species appreciated by native bees. Food competition among bees was low. The vegetation in newly forested areas did not completely meet the food needs of the bees. The cultivation of a great diversity of native plants and bee species in degraded areas and under reforestation certainly yields a good result more quickly.

Impact of alien fishes on the distribution pattern of indigenous freshwater fishes of Punjab, Pakistan.

Pakistan is the country with mega freshwater fish diversity of native and alien species. In the presence of enormous native fishes varies species of exotic fishes have been introduced into the freshwater bodies of Pakistan which are competing with native freshwater fish fauna and making them deprive of food and habitat as well. Intentional or accidental introductions of animals, plants and pathogens away from their native niche is considered as major leading problem for biodiversity of invaded habitat. Three years study (from January 2017 to December 2019) was conducted in freshwater bodies of Province Punjab, Pakistan. Study was designed to know exotic species impacts on the distribution of native species of fishes. During current survey a total of 68 (indigenous and exotic) fish species belonging to 14 families were recorded from head Qadirabad, head Baloki, Islam headworks and Rasul barrage. Statistical analysis showed that Shannon-Wiener diversity index was the highest (1.41) at both Rasul barrage and Islam headworks but, invasive species were present in very less number in these study sites i.e. Oreochromis mozambicus, O. niloticus, Hypophthalmichthys nobilis, Carassius auratus, Ctenophryngdon idella, Cyprinus carpio and H. molitrix. The diversity index showed that comparatively low diversity was present in both area head Qadirabad (1.30) and head Baloki (1.4) due to high pressure of invasive species. Direct observation of species and statistical analysis showed that aliens' species produced negative impact on the local fish fauna diversity, evenness, and numbers. It is concluded that many factors are impacts on the diversity of native fishes, but alien (invasive) species also play a major role to reduction of native species, because aliens' species produce competition for native species. So it is urgent need to analysis the aliens and native food web and roosting sites in Pakistan, in future.

THE AMAZONIAN Arapaima CHANGES ITS STATUS FROM THREATENED SPECIES TO AN INVADER OF EARTH’S FRESHWATER ECOSYSTEMS

A survey of the records was conducted regarding the locations on the planet in which Arapaima has been introduced from its natural habitats in areas of South America, whether for aquaculture or the aquarium trade. Originally, the global expansion of this species was intended to maintain its existence in the face of a perceived risk of extinction. However, the results of the intended and accidental spread of its distribution reveal that Arapaima is an invasive species that can endanger native fish species diversity. It is an air breather, which allows it to inhabit low oxygen conditions of warm tropical water, and a species that grows fast, attaining a large size when mature. It also presents parental care and is a generalist predator that feeds on many other species. Furthermore, it can escape from managed fish farms into natural waterways and establish viable populations without control. From the literature, 228 sites with records of Arapaima from around the world were identified, 95 of which are native sites for the species and 133 are sites where they were introduced. These sites are distributed in 28 countries in the Americas (North, Central and South), Europe, and Asia. Published results of introductions reveal that Arapaima has had negative impacts on native fish species, thus warranting closer attention in regards to how, when and where this species should be allowed.

Genetic diversity of Peltophorum dubium (Spreng.) Taub. progenies from the states of Minas Gerais and Mato Grosso do Sul, Brazil.

There is little information regarding the genetic diversity of native species aimed at identifying the best viable progenies for in situ and ex situ conservation. Furthermore, there is a lack of future forest improvement programs. We aimed to know the genetic diversity of 64 Peltophorum dubium (Spreng.) Taub. (Fabaceae) progenies. We determined this species' dendrometric characteristics, and when using multivariate techniques and cluster analysis, we verified the differences between the progenies and groups with less heterogeneity. The progeny and provenance test was installed in Dourados (Mato Grosso do Sul - MS), with seeds collected in three MS regions (Vale do Ivinhema, Serra de Maracaju, and Serra da Bodoquena) and in the micro-region of Lavras (Minas Gerais - MG). The experiment was conducted in an alpha lattice 8 x 8 with four repetitions. We found genetic variability among and within P. dubium populations for all height, diameter, circumference at breast height, volume, and basal area characters. We suggest that P. dubium populations have high genetic variability, which indicates possible genetic improvement through best progeny selection. The UPGMA and Tocher methods grouped the progenies into three and nine groups, respectively, in which the most divergent individuals come from MG and the Bonito region in MS. Based on morphological characters, P. dubium progenies identified as 45, 47, 49, 50, 55, and 59 from MG are the most promising, while progenies 6 and 9 were the least promising.

Canopy cover and ecological restoration increase natural regeneration of rainforest trees in the Western Ghats, India

Restoration of canopy cover through tree planting can assist in overcoming barriers to natural regeneration and catalyze recovery of degraded tropical forests. India has made international pledges to restore millions of hectares of degraded forests by 2030, but lacks empirical research on regeneration under different types of planted and natural overstories to guide this mission. We conducted a field study (65 plots of 25 m2) to examine the influence of overstory type and canopy cover on naturally regenerating tree seedlings across degraded rainforests (DRs), mixed‐native species ecological restoration (ER) sites, monoculture eucalypt plantations (MP), and mature “benchmark” rainforests (BR) in the Western Ghats mountains of peninsular India. ER had higher native tree seedling densities and recovered community composition toward BR levels compared to DR, while communities in MP shifted in the opposite direction. Densities of native late‐successional species increased with canopy cover (particularly in ER), but greater canopy cover was also associated with increases in alien species, a few of which are shade‐tolerant. Further, in a nursery experiment comprising four rainforest species, seed germination and early survival increased with shade, but did not vary across soils originating from DR, ER, and MP. Our findings show that while improving canopy cover is important, doing so by planting diverse native species, and controlling invasive alien species, can benefit rainforest recovery in DR fragments. Conversely, planting non‐native monocultures in degraded forests, which is a prevalent practice in India, could prove counterproductive for forest recovery in the long term.

Allelopathy effects of invasive alien Ageratina adenophora on native shrub species of chir pine forest in the central Himalaya, India

ABSTRACT Ageratina adenophora Spreng. is one of the most troublesome invasive species that has invaded various forest ecosystems in the central Himalaya. The chir pine (Pinus roxburghii Sarg.) forests in the region facing a high risk of invasion and loss understory diversity of native species. The present study comprehends the allelopathy effect of the invasive species A. adenophora residues bioassay (extract) and soil amendment against two co-occurring native shrubs viz Berberis asiatica Roxb. Ex DC. and Rubus ellipticus Sm. in a laboratory and natural forest conditions. Results revealed that a higher concentration (4% and 8%) of A. adenophora leaf, root and shoot extract have significantly inhibited (23% to 76%) and low concentration (1%) did not inhibit the seed germination, root and shoot length of B. asiatica and R. ellipticus. Furthermore, 8% (w/w) A. adenophora residue (leaf, root and shoot) amendments with the natural soil also showed significant inhibition effects (13% to 37%) on seedling growth and biomass of both the test species. Weekly A. adenophora leaf residue amendment showed higher inhibition in shoot elongation than root and shoot amendment during the experiment period. The study demonstrated that A. adenophora extract and residue amendment have strong allelopathic effects on woody shrub species and indicating allelopathy played important role in the successful establishment and rapid spread of A. adenophora in the understory of chir pine forests.

Reintroduction of native plants indicates the return of ecosystem services after iron mining at the Urucum Massif

AbstractTo reduce the net losses of biodiversity and ecosystem services caused by iron ore mining in Brazil, mineland rehabilitation using native plant species is necessary. However, systematic knowledge about which plant species are the best candidates for mineland rehabilitation is lacking. Therefore, iron mining companies working on the Urucum Massif reintroduce as many native herb and shrub species as possible to achieve the rehabilitation of savanna vegetation communities. To this end, seeds are collected from nearby native ecosystems, and seedlings are rescued from logged areas or produced in a local nursery. Monitoring is necessary to assess the persistence of the reinstated communities and their similarity to natural reference conditions. Ideally, monitoring efforts should compare the floristic composition of the rehabilitating sites with that of natural reference ecosystems. Here, we compared sites that had undergone two or three years of rehabilitation after iron ore mining on the Urucum Massif, MS, Brazil, with native reference sites. The species composition as well as structural, taxonomic, and phylogenetic diversity indices were compared between the reference and rehabilitating sites. Despite the differences in species composition between the rehabilitating and reference sites, we found more than 50 native species and partial recovery of the vegetation structure in the rehabilitating sites. Furthermore, we detected similar levels of animal‐dispersed plant species at rehabilitating and reference sites. These environmental indicators indicate that trial‐and‐error approaches are indeed able to establish considerable native species diversity during mineland rehabilitation. Furthermore, the partial recovery of the vegetation structure suggests the gradual return of soil functions in the long term, and the presence of zoochorous species is expected to attract seed‐dispersing animals that enable gene flow as well as the arrival of additional plant species. Nevertheless, the high cover values of alien exotic species, which are negatively correlated with the diversity of the reinstated communities, endanger the success of mineland rehabilitation in the Urucum Massif, and effective control methods for invasive populations are required. These efforts should be accompanied by enrichment plantings to maintain the diversity of native plant communities at the rehabilitation sites and ongoing environmental monitoring.

Diversifying bioenergy crops increases yield and yield stability by reducing weed abundance.

Relationships between species diversity, productivity, temporal stability of productivity, and plant invasion have been well documented in grasslands, and these relationships could translate to improved agricultural sustainability. However, few studies have explored these relationships in agricultural contexts where fertility and weeds are managed. Using 7 years of biomass yield and species composition data from 12 species mixture treatments varying in native species diversity, we found that species richness increased yield and interannual yield stability by reducing weed abundance. Stability was driven by yield as opposed to temporal variability of yield. Nitrogen fertilization increased yield but at the expense of yield stability. We show how relationships between diversity, species asynchrony, invasion, productivity, and stability observed in natural grasslands can extend into managed agricultural systems. Increasing bioenergy crop diversity can improve farmer economics via increased yield, reduced yield variability, and reduced inputs for weed control, thus promoting perennial vegetation on agricultural lands.

Floristics and Diversity of Invasive Alien Plant Species in Humbo District, South Ethiopia

Deliberate and unintentional introduction of invasive alien plant species on native biodiversity by aid agencies and other bodies directly or indirectly are being a series of problems on the economy, ecology, politics, and health of life on earth. Identifying and compiling floristics and the status of invasive alien species and identifying which have viable populations are necessary to manage the ecosystems. The present study is therefore intended to provide information for concerned bodies on the area which needs management priority computing the composition, structure, and diversity of invasive alien plants. A field assessment was conducted to determine the distribution and heterogeneity of invasive alien plant species, and then, six kebeles were chosen and transact lines were laid using a purposeful sampling technique. The vegetation and environment data were collected from farmland, grazing land, fallow land, and road sides using 95 subquadrats (5 m × 5 m) set in the center and corner of 19 main quadrats (20 m × 20 m). The voucher specimens collected were taken to the Herbarium of Ethiopia (ETH) for taxonomic identification and future reference. The frequency and density of floristics data were analyzed using MS Excel version 2010, and species diversity was calculated using Shannon (H′), Simpson (D), and evenness (E) indices. Among 35 alien plant species invading natural vegetation in Ethiopia, 25 alien plant species were found in the Humbo district of the Wolaita zone. The densest invasive alien plant species in the area were Parthenium hysterophorus consisting of 15197 individuals/ha, followed by Richardia scabra consisting of 11908 individuals/ha, Xanthium strumarium consisting of 7292 individuals/ha, and Ocimum forskolei consisting of 6280 individuals/ha. The highest species diversity was computed in fallow land (H′ = 2.369), which is followed by farmland (H′ = 1.627) and grazing land (H′ = 1.419). The higher the density of the invasive alien species, the higher the ability to change the structure and diversity of native species of the area results in a decrease in the function and services of the ecosystem. Therefore, management methods must prioritize land types that had the highest diversity of invasive alien species.

Identifying thresholds in the impacts of an invasive groundcover on native vegetation

Impacts of invasive species are often difficult to quantify, meaning that many invaders are prioritised for management without robust, contextual evidence of impact. Most impact studies for invasive plants compare heavily invaded with non-invaded sites, revealing little about abundance–impact relationships. We examined effects of increasing cover and volume of the non-native herbaceous groundcover Tradescantia fluminensis on a temperate rainforest community of southern Australia. We hypothesised that there would be critical thresholds in T. fluminensis abundance, below which the native plant community would not be significantly impacted, but above which the community’s condition would degrade markedly. We modelled the abundance–impact relationship from 83 plots that varied in T. fluminensis abundance and landscape context and found the responses of almost all native plant indicators to invasion were non-linear. Native species richness, abundance and diversity exhibited negative exponential relationships with increasing T. fluminensis volume, but negative threshold relationships with increasing T. fluminensis cover. In the latter case, all metrics were relatively stable until cover reached between 20 and 30%, after which each decreased linearly, with a 50% decline occurring at 75–80% invader cover. Few growth forms (notably shrubs and climbers) exhibited such thresholds, with most exhibiting negative exponential relationships. Tradescantia fluminensis biomass increased dramatically at > 80% cover, with few native species able to persist at such high levels of invasion. Landscape context had almost no influence on native communities, or the abundance–impact relationships between T. fluminensis and the plant community metrics. Our results suggest that the diversity of native rainforest community can be maintained where T. fluminensis is present at moderate-to-low cover levels.

Species richness, phylogenetic diversity and phylogenetic structure patterns of exotic and native plants along an elevational gradient in the Himalaya

BackgroundSo far, macroecological studies in the Himalaya have mostly concentrated on spatial variation of overall species richness along the elevational gradient. Very few studies have attempted to document the difference in elevational richness patterns of native and exotic species. In this study, this knowledge gap is addressed by integrating data on phylogeny and elevational distribution of species to identify the variation in species richness, phylogenetic diversity and phylogenetic structure of exotic and native plant species along an elevational gradient in the Himalaya.ResultsSpecies distribution patterns for exotic and native species differed; exotics tended to show maximum species richness at low elevations while natives tended to predominate at mid-elevations. Native species assemblages showed higher phylogenetic diversity than the exotic species assemblages over the entire elevational gradient in the Himalaya. In terms of phylogenetic structure, exotic species assemblages showed majorly phylogenetic clustering while native species assemblages were characterized by phylogenetic overdispersion over the entire gradient.ConclusionsThe findings of this study indicate that areas with high native species richness and phylogenetic diversity are less receptive to exotic species and vice versa in the Himalaya. Species assemblages with high native phylogenetic overdispersion are less receptive to exotic species than the phylogenetically clustered assemblages. Different ecological processes (ecological filtering in case of exotics and resource and niche competition in case of natives) may govern the distribution of exotic and native species along the elevational gradient in the Himalaya.

Effects of variable-density thinning on non-native understory plants in coniferous forests of the Pacific Northwest

Old-growth forests serve as critical habitat for many sensitive species, but management practices have diminished their prevalence, and former regions of old-growth are now dominated by second-growth stands lacking the structural heterogeneity, diversity, and species richness that these older forests possess.In western Washington state in the Pacific Northwest of the United States, the Olympic Habitat Development Study was designed to address this issue and hasten the development of specific old-growth features in second-growth stands using variable-density thinning. One concern with such methods, however, is the potential to introduce non-native plants, which can have negative ecological and economic impacts. Here, we examine how variable-density thinning influences desirable forest characteristics, such as increased plant species diversity, versus the less desirable effects of non-native plant species introduction. We test two hypotheses regarding plant invasions. First, thinning would promote establishment of non-native, shade-intolerant species, but their abundance would gradually decline over time. Second, thinning disturbance and increased heterogeneity of canopy cover would initially promote understory richness of all species, although richness would decline over time with canopy closure and increased cover of shrubs and regenerating trees. We found that the number and cover of non-native species initially increased after thinning, peaking at 16 species present in variable-density thinned treatments in year three. By year 17, 11 species remained throughout the seven 6.5 ha treatment plots sampled, and cover was negligible. As predicted, species richness increased following thinning, however, native species richness remained elevated through year 17, contrary to our hypothesis. Furthermore, native species diversity also increased following thinning and remained higher in thinned treatments than controls through year 17. Our results show that variable-density thinning in temperate coniferous forests can enhance native, but not exotic, plant richness and diversity in the long term.

Diversity and abundance of terrestrial Gastropods on the slopes of Mount Arjuna-Welirang, East Java, Indonesia

Abstract. Nurhayati PA, Affandi M, Nurinsiyah AS. 2021. Diversity and abundance of terrestrial Gastropods on the slopes of Mount Arjuna-Welirang, East Java, Indonesia. Biodiversitas 22: 4193-4202. Before this study, the latest list of land snail species from Mt. Arjuna-Welirang was published in 1952. The current study aims to update the list of terrestrial Gastropods in the area, focusing on Sumber Brantas Arboretum and Raden Soerjo Forest Park Conservation Area (Tahura), East Java, Indonesia. Live snails and dead shells were collected from 24 10 × 10 m2 sampling plots to determine species richness, composition, and abundance. Sampling was carried out by combining visual observation (direct collection) and sorting-sieving soil-leaf litter samples. Total 646 specimens belonging to eight families and 13 species were collected, all new records to the area. Thus, the number of species known from Mt. Arjuna-Welirang was increased to 16 species from nine families. The diversity index of the Mt. Arjuna-Welirang slope was 1.1, and the dominance index was 0.54. The Tahura had a higher diversity index than the Arboretum, at 2.0 and 0.38, respectively, but the dominance index for Tahura was lower (0.18 and 0.85, respectively). This was due to the dominance of Bradybaena similaris, an invasive species in the latter area. Less canopy cover and more human activity in the Arboretum are factors that might cause this discrepancy. Many land snail species are sensitive to desiccation and habitat disturbance. Therefore, minimizing habitat changes and human activities is necessary to maintain or increase native land snail species diversity.

Effects of elevated CO2 concentration and nitrogen addition on foliar phosphorus fractions of Mikania micranatha and Chromolaena odorata under low phosphorus availability.

Invasive plants rapidly spread in habitats with low soil phosphorus (P) availability and have triggered a sharp decline in the diversity of native species. However, no studies have explored how widespread invasive species acclimate to low soil P availability via changing foliar P fractions, especially under elevated atmospheric CO2 concentrations ([CO2 ]) and nitrogen (N) deposition. Here, an open-top chamber experiment was conducted to explore the effect of nutrient addition and elevated [CO2 ] on leaf traits and foliar functional P fractions (i.e., Pi, metabolite P, lipid P, nucleic acid P, and residual P) of two aggressive invasive species (Mikania micranatha and Chromolaena odorata). We found that foliar N/P ratios were more than 20, and P addition significantly increased plant biomass. Both results indicated P-limited plant growth at our studied site. Elevated [CO2 ], N and N + P addition greatly increased plant biomass, photosynthetic rates, and photosynthetic P-use efficiency (PPUE) in invasive species, but PPUE decreased with increasing P addition. Nitrogen addition slightly decreased the concentration of leaf total P, decreased foliar residual P, but increased metabolite P concentrations in invasive species. Similar changes in foliar P fractions were found under N + P addition. Phosphorus addition increased foliar P concentrations, which was strongly correlated with an increase in metabolite P concentrations in invasive species. Elevated [CO2 ] alleviated these effects and increased PPUE. The present results suggest that future elevated [CO2 ] and N deposition allow the invasive species to acclimate to low soil P availability and support their successful invasion by greatly reducing P allocation to non-metabolite foliar P fractions (i.e., nucleic acid P and residual P) to meet their demand of metabolite P for photosynthesis and exhibit a high PPUE.