The influence of climate change on the suitable habitats of Allium species endemic to Iran

Future of Three Endemic Woody Species of Colutea (Fabaceae) in a Changing Climate in Iran

Woody plants offer valuable services to ecosystems, including providing useful products, stabilizing ecosystems, and mitigating climate and pollution effects. However, they face significant abiotic and biotic stresses, with climate change being the most critical challenge. It is essential to understand that reducing populations of woody species, particularly those found only in a specific area, can have severe and irreversible effects on the entire ecosystem. Therefore, exploring the potential influence of climate change on the distribution of endemic woody species is an appealing subject for conservation researchers. This study investigates how climate change affects the distribution of three endemic species of woody plants in the genus Colutea in Iran. The MaxEnt model was used to analyze the data, and the results showed that the model was effective for predicting the impact of climate change on the plants (AUC ≥ 0.9). The distribution of C. persica was significantly affected by solar radiation, Precipitation of Wettest Month, sand, and silt content. C. porphyrogamma's distribution was impacted by Mean Temperature of Coldest Quarter, Precipitation of Driest Month, and Cation Exchange Capacity, while C. triphylla was most affected by Precipitation Seasonality, Precipitation of Driest Quarter, and Isothermality. According to the findings, the distribution of these species is expected to decrease in the 2050s and 2070s due to climate change, based on the RCP4.5 and RCP8.5 climate scenarios. These findings can be useful for developing strategies to manage the impacts of climate change on these species.

Assessing the impact of global warming on the distributions of Allium stipitatum and Kelussia odoratissima in the Central Zagros using a MaxEnt model

Global warming is an undeniable fact occurring in different parts of the world. Climate changes can have irreversible effects on plant communities, particularly on endemic and endangered species. Therefore, it is important to predict the impact of climate change on the distribution of these species to help protect them. This study utilized the MaxEnt model to forecast the impact of climate change on the distributions of two medicinal, edible, and aromatic species, Kelussia odoratissima and Allium stipitatum, in Chaharmahal and Bakhtiari province. The study used the CCSM4 general circulation model along with two climate scenarios, RCP2.6 and RCP8.5, for the 2050s and 2070s to predict the potential impact of climate change on the distribution of the species studied. The research findings indicated that the model performed effectively for prediction (AUC≥0.9). The primary environmental variables influencing species distribution were found to be isothermality (Bio3), soil organic carbon, and pH for A. stipitatum, and soil organic carbon, precipitation seasonality (Bio15), and precipitation of the wettest month (Bio13) for K. odoratissima. The findings suggest that the distribution of the studied species is expected to decline in the 2050s and 2070s due to climate change, under both the RCP2.6 and RCP8.5 climate scenarios. The research indicates that climate change is likely to have a significantly negative effect on the habitats of these species, leading to important ecological and socio-economic impacts. Therefore, our study emphasizes the urgent need for conservation efforts to prevent their extinction and protect their habitats.

Climate change extinctions

Climate change is expected to cause irreversible changes to biodiversity, but predicting those risks remains uncertain. I synthesized 485 studies and more than 5 million projections to produce a quantitative global assessment of climate change extinctions. With increased certainty, this meta-analysis suggests that extinctions will accelerate rapidly if global temperatures exceed 1.5°C. The highest-emission scenario would threaten approximately one-third of species, globally. Amphibians; species from mountain, island, and freshwater ecosystems; and species inhabiting South America, Australia, and New Zealand face the greatest threats. In line with predictions, climate change has contributed to an increasing proportion of observed global extinctions since 1970. Besides limiting greenhouse gases, pinpointing which species to protect first will be critical for preserving biodiversity until anthropogenic climate change is halted and reversed.

Modeling the richness and spatial distribution of the wild relatives of Iranian pears (Pyrus L.) for conservation management

The preservation of the genetic resources of crop wild relatives (CWRs) is crucial for food production systems and is considered a vital measure for global agricultural health and food security. The identification of potential areas where CWRs can thrive is one of the first steps towards their conservation. In this study, we used a maximum entropy model (MaxEnt) to determine the habitat suitability of seven wild relatives of pears (Pyrus L.) for the first time. We aimed to identify high-priority areas for conservation and determine the hotspots for rich biodiversity in Iran. The study showed excellent predictive performance for all species studied (AUC value ≥ 90). The soil depth, solar radiation, minimum temperature of the coldest month (Bio6), and precipitation of the wettest quarter (Bio16) were the main environmental factors that influenced the habitat suitability of all seven species, according to permutation importance. The projected maps revealed that P. elaeagnifolia had the largest suitable habitat area, while P. glabra had the lowest. The results also showed that less than 5% of the suitable habitats for these seven species were in protected areas. This research highlights the need for national preservation policies and the development of cultivation and rehabilitation strategies for these threatened species.

Population status, habitat preferences and predictive current and future distributions of three endangered Silene species under changing climate

One of the most crucial steps in the practical conservation of endangered endemic mountain plants is to address their population size status and habitat requirements concurrently with understanding their response to future global warming. Three endangered Silene species-Silene leucophylla Boiss., S. schimperiana Boiss., and S. oreosinaica Chowdhuri-in Egypt were the focus of the current study. These species were examined for population status change, habitat quality variables (topography, soil features, and threats), and predictive current and future distributions. To find population size changes, recent field surveys and historical records were compared. Using Random Forest (RF) and Canonical Correspondence Analysis (CCA), habitat preferences were assessed. To forecast present-day distribution and climate change response, an ensemble model was used. The results reported a continuous decline in the population size of the three species. Both RF and CCA addressed that elevation, soil texture (silt, sand, and clay fractions), soil moisture, habitat-type, chlorides, electric conductivity, and slope were among the important variables associated with habitat quality. The central northern sector of the Saint Catherine area is the hotspot location for the predictive current distribution of three species with suitable areas of 291.40, 293.10, and 58.29 km2 for S. leucophylla, S. schimperiana, and S. oreosinaica, respectively. Precipitation-related variables and elevation were the key predictors for the current distribution of three Silene species. In response to climate change scenarios, the three Silene species exhibited a gradual contraction in the predictive suitable areas with upward shifts by 2050 and 2070. The protection of these species and reintroduction to the predicted current and future climatically suitable areas are urgent priorities. Ex-situ conservation and raised surveillance, as well as fenced enclosures may catapult as promising and effective approaches to conserving such threatened species.

Habitat potential modelling and the effect of climate change on the current and future distribution of three Thymus species in Iran using MaxEnt

Over the course of a few decades, climate change has caused a rapid and alarming reshaping of species habitats, resulting in mass extinction, particularly among sensitive species. In order to investigate the effects of climate change on species distribution and assess habitat suitability, researchers have developed species distribution models (SDMs) that estimate present and future species distribution. In West Asia, thyme species such as T. fedtschenkoi, T. pubescens, and T. transcaucasicus are rich in thymol and carvacrol, and are commonly used as herbal tea, spice, flavoring agents, and medicinal plants. This study aims to model the distribution of these Thymus species in Iran using the MaxEnt model under two representative concentration pathways (RCP 4.5 and RCP 8.5) for the years 2050 and 2070. The objective is to identify the crucial bioclimatic (n = 5), edaphic (n = 1), and topographic (n = 3) variables that influence their distribution and predict how their distribution might change under various climate scenarios. The findings reveal that the most significant variable affecting T. fedtschenkoi and T. pubescens is altitude, while soil organic carbon content is the primary factor influencing the distribution of T. transcaucasicus. The MaxEnt modeling demonstrates excellent performance, as indicated by all the area under the curve (AUC) values exceeding 0.9. Based on the projections, it is expected that these three thyme species will experience negative area changes in the coming years. These results can serve as a valuable tool for developing adaptive management strategies aimed at enhancing protection and sustainable utilization in the context of global climate change. Special attention should be given to conserving T. fedtschenkoi, T. pubescens, and T. transcaucasicus due to their significant habitat loss in the future.

Potentially suitable distribution areas of Populus euphratica and Tamarix chinensis by MaxEnt and random forest model in the lower reaches of the Heihe River, China

Populus euphratica and Tamarix chinensis play a vital role in windbreak and sand fixation, maintaining species diversity and ensuring community stability. Managing and protecting the P. euphratica and T. chinensis forests in the Heihe River's lower reaches is an urgent issue to maintain the desert region's ecological balance. In this study, based on the distribution points of P. euphratica and T. chinensis species and environmental data, MaxEnt and random forest (RF) models were used to characterize the potential distribution areas of P. euphratica and T. chinensis in the lower reaches of the Heihe River. The results showed that the accuracy of the RF model was much higher than that of the MaxEnt model. Both the RF and MaxEnt models showed that the distance to the river greatly influenced the distribution of P. euphratica and T. chinensis. Furthermore, the RF model predicted significantly larger highly suitable areas for both P. euphratica and T. chinensis than the MaxEnt model. Our study enhances the understanding of the species' spatial distribution, offering valuable insights for practical management and conservation strategies.

Predicting the potential impacts of climate change on the endangered endemic annonaceae species in east africa

Globally, endemic species and natural habitats have been significantly impacted by climate change, and further considerable impacts are predicted. Therefore, understanding how endemic species are impacted by climate change can aid in advancing the necessary conservation initiatives. The use of niche modeling is becoming a popular topic in biological conservation to forecast changes in species distributions under various climate change scenarios. This study used the Australian Community Climate and Earth System Simulator version 1 (ACCESS-CM2) general circulation model of coupled model intercomparison project phase 6 (CMIP6) to model the current distribution of suitable habitat for the four threatened Annonaceae species endemic to East Africa (EA), to determine the impact of climate change on their suitable habitat in the years 2050 (average for 2041-2060) and 2070 (average for 2061-2080). Two shared socio-economic pathways (SSPs) SSP370 and SSP585 were used to project the contraction and expansion of suitable habitats for Uvariodendron kirkii, Uvaria kirkii, Uvariodendron dzomboense and Asteranthe asterias endemic to Kenya and Tanzania in EA. The current distribution for all four species is highly influenced by precipitation, temperature, and environmental factors (population, potential evapotranspiration, and aridity index). Although the loss of the original suitable habitat is anticipated to be significant, appropriate habitat expansion and contraction are projections for all species. More than 70% and 40% of the original habitats of Uvariodendron dzombense and Uvariodendron kirkii are predicted to be destroyed by climate change, respectively. Based on our research, we suggest that areas that are expected to shrink owing to climate change be classified as important protection zones for the preservation of Annonaceae species.