Environmental Resource Availability Research Articles

Addressing the Scientific Gaps Between Life Cycle Thinking and Multi-Criteria Decision Analysis for the Sustainability Assessment of Electric Vehicles’ Lithium-Ion Batteries

Electric vehicles can substantially lower the overall carbon footprint of the transportation sector, and their batteries become key enablers of widespread electrification. Although high capacity and efficiency are essential for providing sufficient range and performance in electric vehicles, they can be compromised by the need to lower costs and environmental impacts and retain valuable materials. In the present work, multi-criteria decision analysis was adopted to assess the sustainability of different lithium-ion batteries. Life cycle carbon emissions and toxicity, material criticality, life cycle costs, specific energy, safety, and durability were considered in the analysis as key parameters of the transition to electric mobility. A subjective approach was chosen for the weight attribution of the criteria. Although certain alternatives, like lithium nickel cobalt manganese oxide (NCM) and lithium nickel cobalt aluminum oxide (NCA), outweigh others in specific energy, they lack in terms of safety, material preservation, and environmental impact. Addressing cost-related challenges is also important for making certain solutions competitive and largely accessible. Overall, while technical parameters are crucial for the development of lithium-ion batteries, it is equally important to consider the environmental burden, resource availability, and economic factors in the design process, alongside social aspects such as the ethical sourcing of materials to ensure their sustainability.

Environmental Stress and Resource Availability Affect the Maintenance of Genetic Variation in a Dominant Marsh Plant (Spartina alterniflora).

Changes in genetic variation, and particularly documented declines in genetic diversity, influence not only evolutionary potential but also current ecological function. Given this context, it is essential to understand what abiotic and biotic factors promote or disrupt the maintenance of genetic variation in natural populations. To address this knowledge gap in the context of salt marsh plants, we established a three-year field experiment, testing the independent and interactive effects of nutrient availability and physical stress on the maintenance of plant (Spartina alterniflora) genotypic diversity. We found that in environments with high physical stress (i.e., low marsh elevations), diversity declined over time. However, the addition of nutrients promoted the maintenance of Spartina genotypic diversity across the physical stress gradient. We also observed changes in genotypic composition and genetic divergence across environmental stress treatments, indicating variation among Spartina genotypes in their response to these factors. Our results suggest that tidal inundation acts a selective gradient within coastal marshes, altering genotypic diversity and composition across the landscape. Moreover, our work highlights that the effects of increasing inundation due to continued sea-level rise on the maintenance of diversity may be modulated by concomitant changes in nutrient inputs, with cascading effects on marsh structure and function.

Beyond the Surface: Mesophotic Reefs as Potential Refuges for Shallow Fish Assemblages.

The deep reef refugia hypothesis suggests that the effects of disturbance decrease as depth increases; thus, reefs in the mesophotic zone potentially serve as refuges for communities in shallower zones. This study challenged this hypothesis by evaluating fish diversity in shallow and mesophotic reefs in a marine protected area in the Gulf of California. During 2021-2022, we conducted 189 5-min video transects using remotely operated vehicles to document species richness and abundance. We evaluated six biological traits for each species (length, mobility, position, gregariousness, diet, and activity period) to estimate four functional indices (number of entities, richness, originality, and divergence), one phylogenetic index (Δ*), and Hill's numbers for taxonomic and functional indices. Benthic organisms were analyzed to explore relationships with ichthyofauna, while monthly water turbidity satellite data products were transformed into a light attenuation coefficient to identify the mesophotic zone (area between 10% and 0.1% of the incident light at the surface). At the study site, the mesophotic zone was identified to extend to 21 m under optimal conditions, which is shallower than what is typically observed in oligotrophic regions. Generalized linear models revealed significant variations in reef fish composition across spatial (site and zone) and temporal (season and year) dimensions. Additionally, generalized linear mixed models of functional richness and taxonomic Hill's numbers exhibited significantly higher values in the shallow zone. However, functional and phylogenetic indices showed similarities in fish assemblages. Despite differences in fish taxonomic diversity among zones that could be related to less environmental variation and resource availability in deep strata, mesophotic reef fish assemblages presented similar functions. Functions were maintained in mesophotic reefs, which suggests that the two zones are connected and that mesophotic reefs have the potential to act as partial refugia in the face of current and near-future climate change-related disturbances that could affect shallow zones.

Strategi Pengembangan Usaha Budidaya Ikan Nila (Oreochromis niloticus) di Desa Sukamantri, Kecamatan Tamansari, Kabupaten Bogor

Red tilapia (Oreochromis niloticus) is a freshwater fish known for its high tolerance to environmental conditions, low water quality, and ability to adapt well to various situations. Data from the Ministry of Marine Affairs and Fisheries shows that tilapia production in Indonesia has increased significantly, from 1,172,633.38 kg in 2020 to 1,300,529.23 kilograms in 2021, with a percentage increase of 10.90%. The community strongly influences the local economy and food security. Tilapia farming is widely chosen because it has a stable selling price and fast growth. Many farmers have chosen Tilapia farming as their primary source of livelihood. This research aimed to study the socio-economic conditions, difficulties, and development opportunities of tilapia farming in the community. The results show that although this business contributes significantly to family income, there are several constraints, such as fluctuating market prices, limited access to technology, and low aquaculture skills. In addition, the success of aquaculture is also affected by environmental conditions and resource availability. Therefore, a development plan that includes training, access to capital, and improved infrastructure is needed to improve yields and the welfare of the tilapia farming community.

Bridging Matera’s Fragmented Identity: Unifying Disconnected Urban Spaces

The city, like a piece of architecture, is a structure in space, but one of gigantic scale, something perceived only over a long period. A space is termed a place when it acquires an identity. The entirety of urban personality, urban communication, urban conduct, and urban design constitute the urban identity. This research delves into divided urban identities and examines how urban and architectural design influence the fragmentation of the cityscape. It explores the connection between urban environments’ physical attributes and the divide of social, cultural, and political identities within cities. This study uses a multidisciplinary method to acquire thorough knowledge by combining architectural studies, urban planning theories, and social-cultural perspectives. The case study of reference is the city of Matera, in southern Italy, which has a unique history of a slow shaping of its urban and productive landscape throughout centuries due to heavy environmental constraints and resource availability and which has suffered forced evacuation and major discontinuities in the past century. Here, the opposing traits of the historical Sassi district and the new town are examined, focusing on their resulting separated urban identities. The study also looks at how divided cities may be reconciled and integrated, emphasizing the relevance of a holistic urban approach for the framing of complex issues. The research proposes methods and best practices for developing inclusive urban settings that promote cohesion and shared identities through the analysis of successful cases of urban regeneration, adaptive reuse of spaces, and participatory design processes. The findings of this research contribute to both academic and practical knowledge by deepening the understanding of the relationship between urban design, architecture, and divided urban identities. It emphasizes the value of comprehensive approaches to urban planning that take into account the social, cultural, and historical settings of cities to foster inclusivity, rapprochement, and the development of common urban identities.

Trophic Ecology and Behavioral Pattern of the Vizcachera Owl, Athene cunicularia Molina, 1782 (Strigiformes: Strigidae) in an Urban Environment in Southern Santa Fe province, Argentina

This study investigates the trophic ecology and behavioral patterns of Athene cunicularia in Funes, Santa Fe, Argentina, during 2023-2024. Observations were made of two individuals throughout the four seasons of the year, recording a total of 16 hours of behavior. The results revealed that the owl showed a varied diet composed of 946 prey items identified in 134 pellets, with arthropods as the main source (91.89%). The pellets presented an average size of 31.98 mm and a weight of 1.31 g. Seven behavioral patterns were identified, with rest being the most frequent, especially in autumn and winter. Variations in diet and behavior appear to reflect adaptations to environmental conditions and resource availability, suggesting that the species is opportunistic and generalist. These findings contribute to the understanding of the ecology of A. cunicularia in urban environments, highlighting its role in the local ecological balance.

A Study on Future Population Dynamics of Indigenous Earthworm Species in Golaghat District of Assam, India

This study presents a pioneering exploration into the population dynamics of indigenous earthworm species in the Golaghat district of Assam, India, through the lens of mathematical modeling. Recognizing the integral role of earthworms in enhancing soil productivity and ecosystem health, we embarked on a detailed longitudinal analysis spanning from 2018 to 2023 to assess their population trends across different seasons and subdivisions within the district. Utilizing the principles of Mathematical Biology, we employed the Malthus Growth model and the Logistic Growth model to estimate future population trajectories of earthworm species, integrating biological insights with mathematical rigor. Our methodology, combining extensive field data collection with sophisticated mathematical modeling, provides a replicable framework for similar ecological studies. This study contributes to the growing field of Mathematical Biology, offering a novel approach to understanding the complex interactions within ecosystems and the impact of environmental changes on key species. The outcomes offer valuable insights into sustainable agricultural practices and biodiversity conservation in tropical and subtropical regions, emphasizing the critical role of indigenous earthworm species in maintaining soil health and ecosystem services. Our findings reveal significant seasonal variations and highlight the resilience of these species in the face of ecological changes. The models suggest distinct population growth patterns, with the Logistic model providing a more realistic projection considering environmental constraints and resource availability. The bifurcation diagram is drawn for the Logistic map that presents the phenomena inside the chaotic region.

Diet of schistosome vectors influences infection outcomes

AbstractResource availability can alter infection outcomes through its impact on host immunity and on parasite reproduction. On one hand, enhanced nutrition could favor immunity, limiting the parasite, and on the other hand, it could favor establishment and reproduction of the parasite. Our study aimed to determine the effect of diet on (1) host susceptibility to infection and (2) parasite production in a snail‐trematode system. We fed Biomphalaria sudanica, a snail vector of Schistosoma mansoni, either a strict lettuce (low nutrient) or pellet (high nutrient) diet for two generations before exposing them to S. mansoni. We used two parasite strains, one that is incompatible with the snails and one that is compatible with the snails. We found that when exposed to incompatible parasites, diet did not affect snail susceptibility significantly as few snails were infected overall. However, when challenged with the compatible parasites, snails fed the high‐nutrient diet were more susceptible to infection than their low‐nutrient‐fed counterparts. The high‐nutrient‐fed snails also produced more cercariae than low‐nutrient‐fed snails, but this advantage was lost after the initial assessment at 8 weeks. Snails that obtained infections were either kept on their initial diet or switched to the other diet. This experiment showed that snails switched from a low‐to‐high‐nutrient diet produced more cercariae than those remaining on the low‐nutrient diet and similar numbers to those remaining on the high‐nutrient diet. Unexpectedly, the reciprocal diet switch (high to low nutrient) initially resulted in more cercariae relative to controls, but the pattern reversed after initial assessment. This study showed that available resources can impact the susceptibility of the vector host and the reproductive capacity of the parasites, with higher nutrients favoring parasite establishment and reproduction, highlighting the plasticity of susceptibility phenotypes, which also have a strong genetic basis. These data can aid predictions of how future environmental changes and resource availability may impact parasite transmission.

Spatial analyses of archaeobotanical record reveal site uses and activities at Early to Middle Holocene Takarkori (Libya, Central Sahara).

This study investigates botanical remains from the Takarkori site in the Tadrart Acacus region (SW Libya) to reconstruct socio-economic and cultural characteristics of human groups during the Holocene. By analyzing micro- and macrofossils of plant origin, we aim to understand the availability and management of environmental resources and how plant taxa were used by humans. The exceptional preservation of archaeobotanical material across all occupation levels, facilitated by the region's geomorphological and environmental conditions, provides a unique opportunity to study pre-Pastoral and Pastoral Neolithic activities within a comprehensive diachronic framework. Our research extends previous investigations by examining the spatial distribution of archaeobotanical remains in association with site furniture and material correlates, offering insights into the functional use of space within the site. Also, the features of plant assemblages and their distribution patterns indicate the planning in the use of plant resources and the diverse uses beyond subsistence, including ritual and cultural practices. The findings contribute to a deeper understanding of Holocene environmental and cultural dynamics, highlighting the importance of archaeobotanical data in archaeological research.

Climate drives body mass changes in a mountain ungulate: shorter winters lead to heavier Alpine ibex

Climate affects seasonality and plant phenology, which can influence seasonal body mass dynamics of herbivores in temperate environments. We investigated long‐term trends of seasonal body mass changes in male Alpine ibex Capra ibex. We used SEM to test direct and indirect relationships between body mass, mass changes and environmental and climatic variables. Individually recognizable Alpine ibex were weighed repeatedly between 2000 and 2022 in Gran Paradiso National Park (Italy). Autumn mass increased substantially over these two decades, up to 15% in some age classes. Over the same time frame, both summer mass gain and winter mass loss decreased, suggesting that heavier autumn body mass was due to the cumulative effects of reduced mass loss over several winters. The environmental factor with the strongest effects on winter mass changes was the starting date of vegetation green‐up at low altitude, where ibex gather after winter to feed on new growth vegetation. Early springs led to lower winter mass loss, likely because ibex relied on stored fat for a shorter period and had greater access to forage. High population density also increased winter mass loss. Environmental conditions and resource availability, possibly also influenced by density in winter and early spring, seem therefore to directly affect the body mass dynamics of male Alpine ibex, while the effect of summer conditions appears less relevant. By affecting seasonal body mass dynamics, climate change may have consequences for life history and population dynamics of mountain herbivores, for example via earlier access of young males to reproduction.

Effects of Seasonality on the Large and Medium-Sized Mammal Community in Mountain Dry Forests

Seasonality drives natural processes, impacting environmental factors like temperature and resource availability, leading to shifts in wildlife communities. The Andean dry forests exhibit a marked seasonality, with a dry and cold season (May–September) and a warm, wet season (October–April). In a year-long remote camera survey in Southern Bolivia, we identified 29 medium to large mammal species, 18 outside their known distribution ranges. While overall species richness remained stable, photographic records varied between seasons. Capture rates, reflecting species richness and abundance, were more influenced by season and habitat. Wet season rates were lower, but higher in all other habitats compared to the mountain bush and grasslands. Rates increased with altitude and distance to hiking trails, but decreased with increasing distance from main roads. Medium to large mammals were more active during the dry season, indicating adjustments in response to seasonal changes. Our results suggest a cumulative impact of various factors beyond mere seasonality, and call for adjustments in global species distributions. Moreover, emphasize the need for biodiversity monitoring in dry forest habitats, particularly regarding responses to environmental shifts and human-induced alterations.

A Wireless Wearable Ecosystem for Social Network Analysis in Free-living Animals.

Studying animal social systems requires understanding variations in contact and interaction, influenced by factors like environmental conditions, resource availability, and predation risk. Traditional observational methods have limitations, but advancements in sensor technologies and data analytics provide new opportunities. We developed a wireless wearable sensor system, "Juxta," with features such as modular battery packs and a smartphone app for data collection. A pilot study on free-living prairie voles (Microtus ochrogaster), a species with complex social behavior, demonstrated Juxta's potential for studying social networks and behavior. We propose a framework for merging temporal, spatial, and event-driven data, which can help explore complex social dynamics across species and environments.

Study on the Economic and Technical Optimization of Hybrid Rural Microgrids Integrating Wind, Solar, Biogas, and Energy Storage with AC/DC Conversion

Under the guidance of the 'dual carbon' goals and 'rural revitalization' strategy, the development of microgrids primarily based on wind, solar, and biogas energy is rapidly advancing in rural areas. A critical and challenging area of current research is how to optimally configure the capacity of these microgrids of varying sizes, taking into account the availability of resources in the system's environment and specific climatic conditions, to maximize economic benefits. Based on this, the article constructs a model of a hybrid AC/DC microgrid system powered by wind, solar, and biogas energy. It undertakes multi-objective optimization to achieve the highest utilization of renewable energy, the most economical cost, and the minimum carbon emissions while ensuring the reliability of the system's power supply. The study explores the economically and technically optimal configuration of this microgrid energy system under certain climatic conditions. The results indicate that the optimal configuration for a rural microgrid powered by wind, solar, and biogas energy should include a 2.6 kW biogas generator, 30.00 kW solar panels, 5.24 kW wind turbines, a 2.6 kW battery storage system, and a 10.00 kW bidirectional inverter. This configuration results in the lowest total net cost of the system, achieving optimal outcomes in terms of total net cost, cost per kilowatt-hour, and supply reliability.

Behavioural determinants shaping infection prevention and control behaviour among healthcare workers in Dutch general practices: a qualitative study reflecting on pre-, during and post-COVID-19 pandemic

BackgroundSince the Coronavirus Disease 2019 (COVID-19) pandemic, awareness of infection prevention and control (IPC) has increased in primary care settings. This study aimed to examine behavioural determinants shaping IPC behaviour pre-, during, and post-pandemic among healthcare workers (HCWs) in general practices, to inform optimised IPC in primary care.MethodsFor this qualitative study, semi-structured in-depth interviews were conducted during two study periods: (1) pre-COVID-19 pandemic: July 2019-February 2020, with 14 general practitioners (GPs) and medical assistants, and (2) during the COVID-19 pandemic: July 2022-February 2023, with 22 GPs and medical assistants. The design was informed by behaviour change theories. Data were analysed using thematic analysis.ResultsMain themes were: (1) risk perception and IPC awareness, (2) attitudes towards IPC and professional responsibility, (3) decision-making process and risk considerations for IPC adherence, (4) social norm and social influence in GP practice team, and (5) environmental context and resource availability in GP practice. During the pandemic, risk perception and awareness of the importance of IPC increased compared to the pre-pandemic period. A consistent belief emerged that IPC is part of professional responsibility, while needing to be balanced with other aspects of patient care. Decision-making is dependent on the individual GP and mainly influenced by risk assessments and sustainability considerations. The social context in the practice team can reinforce IPC behaviours. GP practice building and layout, and limited IPC resource and material availability were reported as main barriers.ConclusionsThe theory-informed insights of this study can be used for targeted interventions to optimise IPC behaviour in general practices. Adopting multifaceted strategies to target the various determinants is recommended to sustain IPC, by implementing continuous education using tailored communication, integrating IPC in work routines and organisational workflows, refining existing IPC protocols by incorporating decision-making tools for HCWs, fostering a culture of IPC through knowledge-sharing and teamwork, and addressing GP practice physical environment and IPC resource barriers.

Novel Technological Approaches in Waste Management for Environmental Conservation and Resource Recovery

Efficient waste management has emerged as a critical concern in contemporary society due to its direct impact on environmental sustainability and resource availability. This research delves into innovative technological approaches aimed at revolutionizing waste management practices to mitigate environmental degradation while maximizing resource recovery. The study explores cutting-edge methodologies encompassing waste sorting, recycling, composting, and novel waste-to-energy conversion systems. Additionally, it investigates the integration of artificial intelligence, robotics, and sensor technologies to enhance waste processing efficiency and optimize resource utilization. The overarching goal is to outline a comprehensive framework for sustainable waste management, emphasizing environmental conservation and the circular economy principles. Through this exploration, this research aims to offer insights into the development and implementation of advanced engineering solutions for a greener and more sustainable future. KEYWORDS: Waste Management, Environmental Conservation, Resource Recovery, Recycling Technologies, Waste-to-Energy, Circular Economy, Sustainability

Environmental variables influence patterns of mammal co-occurrence following introduced predator control.

Co-occurring species often overlap in their use of resources and can interact in complex ways. However, shifts in environmental conditions or resource availability can lead to changes in patterns of species co-occurrence, which may be exacerbated by global escalation of human disturbances to ecosystems, including conservation-directed interventions. We investigated the relative abundance and co-occurrence of two naturally sympatric mammal species following two forms of environmental disturbance: wildfire and introduced predator control. Using 14 years of abundance data from repeat surveys at long-term monitoring sites in south-eastern Australia, we examined the association between a marsupial, the common brushtail possum Trichosurus vulpecula, and a co-occurring native rodent, the bush rat Rattus fuscipes. We asked: In a fox-controlled environment, are the abundances of common brushtail possums and bush rats affected by environmental disturbance and each other's presence? Using Bayesian regression models, we tested hypotheses that the abundance of each species would vary with changes in environmental and disturbance variables, and that the negative association between bush rats and common brushtail possums was stronger than the association between bush rats and disturbance. Our analyses revealed that bush rat abundance varied greatly in relation to environmental and disturbance variables, whereas common brushtail possums showed relatively limited variation in response to the same variables. There was a negative association between common brushtail possums and bush rats, but this association was weaker than the initial decline and subsequent recovery of bush rats in response to wildfires. Using co-occurrence analysis, we can infer negative relationships in abundance between co-occurring species, but to understand the impacts of such associations, and plan appropriate conservation measures, we require more information on interactions between the species and environmental variables. Co-occurrence can be a powerful and novel method to diagnose threats to communities and understand changes in ecosystem dynamics.

Ecosystem productivity drives the breeding success of an endangered top avian scavenger in a changing grazing pressure context

Environmental conditions and resource availability shape population dynamics through direct and indirect effects of climate, biological interactions and the human modification of landscape. Even when a species seems dependent on predictable anthropogenic food resources or subsidies, ecosystem-level factors can still determine population dynamics across taxa. However, there is still a knowledge gap about the cascade effects driven by climate, vegetation functioning, resource availability and governmental policies on key aspects of species reproduction for top scavengers. Here we put to good use 22 years (2000−2021) of extensive population monitoring from the endemic Canary Egyptian vulture (Neophron percnopterus majorensis) on the Fuerteventura Island (Canary Islands, Spain) to study the relative importance of demographic factors, ecosystem conditions and availability of anthropogenic food sources on breeding success. Our results suggest that ecosystem-level primary productivity, the number of livestock animals present on the island and Density-dependent processes determine the temporal changes in the breeding success of this species. We firstly accounted for a top-down effect of livestock on island vegetation, where overgrazing directly reduces landscape-level vegetation biomass. We, consequently, found a bottom-up effect between vegetation and the Egyptian vulture's breeding success. In this context, minimal changes in ecological conditions can impact the species inhabiting these ecosystems, with direct consequences on a key population stage, such as breeding season, when energy requirements are higher. These results are especially relevant because cascading and indirect effects of ecosystem processes and governmental policies are often overlooked when pursuing conservation goals of endangered species.

Potential investigation of combined natural dye pigments extracted from ivy gourd leaves, black glutinous rice and turmeric for dye-sensitised solar cell

Environmental sustainability, resource availability, and cost-effectiveness are the driving forces behind the search for natural sensitised dyes to replace synthetic ones. Using a combination of pigments as the sensitised dye in dye-sensitised solar cells (DSSCs) offers several advantages over using a single pigment. In this present study, natural dyes with different pigments were extracted from three local plants: Coccinia grandis (Ivy gourd leaves, IGL), Oryza sativa Linn (Black glutinous rice, BGR), and Curcuma longa L. (Turmeric, TM). Each colour extract absorbed various wavelengths of light. It was found that the single IGL-dye (green) had a greater light absorption and energy band gap over visible light than other extracts (dyes). Then combinations of these dyes were examined. A sensitised dye combination with a primary to secondary dye in a volumetric ratio of 80/20 exhibited multiple energy band gaps, implying multiple electron excitations at different photon energy levels. Compared to other mixed dyes, IGL/TM-dye had the highest absorbance and electron excitation at three wavelengths with the smallest energy band gap values of 1.74, 2.51, and 2.59 eV. The IGL-dye had the highest DSSC efficiency of 0.15 % for single dyes, followed by the TM-dye and BGR-dye, which had 0.12 % and 0.04 %, respectively. Interestingly, for combined dyes, the IGL/TM dye increased DSSC efficiency to 0.3 %. Since natural dyes tend to be less effective in DSSCs than synthetic dyes because they have a narrower absorption range, higher redox potentials, shorter operational lifetimes, higher rates of electron recombination, and different molecular structures, the dye co-sensitization strategy is one of the best ways to make more effective cells in the future.

Nutrition regulates sex expression in a gender diphasy plant, Lilium concolor var. megalanthum.

The evolution and maintenance of plant polymorphism have always received much attention. Gender diphasy is a rare sexual system. Plant individuals with gender diphasy can adjust the resource allocation of different functional organs according to the changes of environmental conditions to regulate the sex expression of individuals, and the sex expression can be converted between years. However, our understanding of sex expression in plants is still very insufficient. In this study, we explored whether the perennial plant Lilium concolor var. megalanthum has a gender diphasy system and whether environmental resource availability affects its resource allocation and sex expression. By collecting the bulbs of two sexual phenotypes (male and hermaphrodite) in the field and simulating the application of different levels of nutrients under the same habitat conditions, the growth and reproduction indexes and sex expression of plants in two years (2021 and 2022) were measured to evaluate the resource allocation strategy and sex expression pattern of Lilium concolor var. megalanthum. We found that the sex expression of Lilium concolor var. megalanthum was variable in continuous years. Under limited resources, Lilium concolor var. megalanthum increases the biomass resources of the leaves and has a longer flowering period. Resource availability regulates the growth, reproduction and sex expression of Lilium concolor var. megalanthum. Bulb size is the main factor affecting its growth, reproduction and sex expression after accumulating sufficient resources. This study confirms that Lilium concolor var. megalanthum has gender diphasy system. There is a strong trade-off between growth and reproduction under limited resources. Nutrient levels can regulate the reproduction and sex expression process of Lilium concolor var. megalanthum. With the growth of Lilium concolor var. megalanthum in consecutive years, the size dependence of bulbs may be the decisive factor in its sex expression.

Woody cover and pasture within the surrounding matrix drive puma (Puma concolor) occupancy in agroecosystems of the Argentine Dry Chaco

The puma (Puma concolor) is distributed over most vegetation types and elevation ranges, but is still sensitive to habitat loss and human persecution. Due to its large spatial requirements, pumas must persist in human-modified landscapes, where vegetation cover and prey availability can limit its occurrence. Few studies have assessed the suite of factors that may influence carnivore persistence in deforestation frontiers such as the Dry Chaco. We explored the influence of landscape structure, native prey availability, and local anthropogenic proxies on puma occupancy in Argentine Dry Chaco agroecosystems through a single-season occupancy framework based on camera-trap surveys. We used the results to predict puma occupancy for the ecoregion. Woody cover and the proportion of pasture within the surrounding matrix influenced puma occupancy: in areas with moderate to little woody cover, puma occupancy was negatively influenced by the proportion of pasture relative to cropland. Predicted puma occupancy probability was very high throughout half of the ecoregion. Our results corroborate the landscape-scale importance of woody cover for the puma in the Dry Chaco. However, the negative relation between puma occupancy and pasture dominance in areas with little woody cover could be suggesting potential negative interactions with humans, or seasonal variations in environmental condictions and resource availability that should be further explored.