Impact of birth pulse and environment shift on population survival and propagation

SUMMARY Potential impacts of climate change on ecosystems and the environment are generally assessed by summarizing climate change scenarios for broad regions (for example countries), or by specific modelling exercises. This paper presents an alternative approach for summarizing climate change impacts on the European environment, by linking climate change scenarios to recognized environmental divisions. Sixteen climate scenarios from four general circulation models were therefore linked to 84 statistically derived strata sharing common environmental features. In this way, the future distribution of the strata, as defined by their climate characteristics, were quantified and mapped. The results show that Europe is likely to experience major environmental shifts, with pronounced regional variations. As expected, environmental strata shift northwards. In particular the southern Mediterranean strata are projected to expand, whereas Atlantic environments remain much more stable. Alpine and Mediterranean mountain environments decline dramatically. However, the Scandinavian zones show no consistent pattern of change. More detailed analysis of four sample regions shows that the impacts of the projected shifts will largely depend on regional characteristics. Environmental conservation, regional assessments and scenario development could therefore be facilitated by combining relevant regional datasets (for example for vegetation, land cover and species distribution) with the shifting environmental strata.

In most models of population dynamics, increases in population due to birth are assumed to be time-independent, but many species reproduce only during a single period of the year. We propose a single-species model with stage structure for the dynamics in a wild animal population for which births occur in a single pulse once per time period. Using the discrete dynamical system determined by the stroboscopic map, we obtain an exact periodic solution of systems which are with Ricker functions or Beverton-Holt functions, and obtain the threshold conditions for their stability. Above this threshold, there is a characteristic sequence of bifurcations, leading to chaotic dynamics, which implies that the dynamical behaviors of the single species model with birth pulses are very complex, including small-amplitude annual oscillations, large-amplitude multi-annual cycles, and chaos. This suggests that birth pulse, in effect, provides a natural period or cyclicity that allows for a period-doubling route to chaos.

In order to be useful in assessing the effects of climate change on biological populations, mathematical models have to adequately represent the life cycle of the species in question, the dynamics of and interactions with its resource(s), and the effect of changing environmental conditions on their vital rates. Due to this complexity, such models are often analytically intractable. We present here a consumer-resource model that captures seasonality (summer and winter), with synchronously reproducing consumers (birth pulse), structured into non-reproductive juveniles and reproductive adults, and that remains analytically tractable. Our model is motivated by hibernating mammals, such as marmots, ground squirrels, or bats, some of which live in high altitude regions where the effects of climate change are stronger than elsewhere. One stage-specific impact of climate change in those species is that juveniles may benefit from warmer winters while adults may suffer. We explore various aspects of how this differential response to climate change shapes population dynamics from stable populations to cycles and chaos. We show that the qualitative relationship between winter temperature and winter mortality has a significant effect on the model dynamics, hence informing empiricists of required data to assess the effect of climate change on these species. Our results question the long-standing expectation that species with slower life histories are necessarily more strongly affected by climate change than species with faster life histories.

Host specialization after host shifting is traditionally viewed as the pathway to speciation in parasitic plants. However, geographical and environmental changes can also influence parasite speciation, through hybridization processes. Here we investigated the impact of past climatic fluctuations, environment, and host shifts on the genetic structure and patterns of hybridization and gene flow between Psittacanthus calyculatus and P. schiedeanus, a Mesoamerican species complex. Using microsatellites (408 individuals), we document moderate genetic diversity but high genetic differentiation between widespread parental clusters, calyculatus in dry pine-oak forests and schiedeanus in cloud forests. Bayesian analyses identified a third cluster, with admixture between parental clusters in areas of xeric and tropical dry forests and high levels of migration rates following secondary contact. Coincidently host associations in these areas differ from those in areas of parental species, suggesting that past hybridization played a role in environmental and host shifts. Overall, the observed genetic and geographic patterns suggest that these Psittacanthus populations could have entered a distinct evolutionary pathway. The results provide evidence for highlights on the importance of the Pleistocene climate changes, habitat differences, and potential host shifts in the evolutionary history of Neotropical mistletoes.

Persistence or extinction of moving animal species is a fundamental question in spatial ecology. This paper focuses on the impact of habitat shift driven by climate change on the persistence and propagation of a population with birth pulse. We first present a class of impulsive reaction-diffusion models with heterogeneous nonlinear reaction in high-dimensional space and study their threshold dynamics. We provide the persistence criterion of the system in bounded domains, and prove the existence, uniqueness, and global attraction of a positive steady state. Then we extend the results from bounded domains to the whole space. Our results indicate how the speed of the shifting habitat edge and impulsive reproduction (or harvesting) rate determine the persistence and extinction of the population. Numerical simulations are presented to illustrate the theoretical results.

Multiple Attractors in Stage-structured Population Models with Birth Pulses

In this paper, the main purpose is to reveal what kind of qualitative dynamical changes a continuous age-structured model may undergo as continuous reproduction is replaced with an annual birth pulse. Using the discrete dynamical system determined by the stroboscopic map we obtain an exact periodic solution of system with density-dependent fertility and obtain the threshold conditions for its stability. We also present formal proofs of the supercritical flip bifurcation at the bifurcation as well as extensive analysis of dynamics in unstable parameter regions. Above this threshold, there is a characteristic sequence of bifurcations, leading to chaotic dynamics, which implies that the dynamical behavior of the single species model with birth pulses are very complex, including small-amplitude annual oscillations, large-amplitude multi-annual cycles, and chaos. This suggests that birth pulse, in effect, provides a natural period or cyclicity that allows for a period-doubling route to chaos. Finally, we discuss the effects of generation delay on stability of positive equilibrium (or positive periodic solution), and show that generation delay is found to act both as a destabilizing and a stabilizing effect.

Forest trees, like oaks, rely on high levels of genetic variation to adapt to varying environmental conditions. Thus, genetic variation and its distribution are important for the long-term survival and adaptability of oak populations. Climate change is projected to lead to increased drought and fire events as well as a northward migration of tree species, including oaks. Additionally, decline in oak regeneration has become increasingly concerning since it may lead to decreased gene flow and increased inbreeding levels. This will in turn lead to lowered levels of genetic diversity, negatively affecting the growth and survival of populations. At the same time, populations at the species’ distribution edge, like those in this study, could possess important stores of genetic diversity and adaptive potential, while also being vulnerable to climatic or anthropogenic changes. A survey of the level and distribution of genetic variation and identification of potentially adaptive genes is needed since adaptive genetic variation is essential for their long-term survival. Oaks possess a remarkable characteristic in that they maintain their species identity and specific environmental adaptations despite their propensity to hybridize. Thus, in the face of interspecific gene flow, some areas of the genome remain differentiated due to selection. This characteristic allows the study of local environmental adaptation through genetic variation analyses. Furthermore, using genic markers with known putative functions makes it possible to link those differentiated markers to potential adaptive traits (e.g., flowering time, drought stress tolerance). Demographic processes like gene flow and genetic drift also play an important role in how genes (including adaptive genes) are maintained or spread. These processes are influenced by disturbances, both natural and anthropogenic. An examination of how genetic variation is geographically distributed can display how these genetic processes and geographical disturbances influence genetic variation patterns. For example, the spatial clustering of closely related trees could promote inbreeding with associated negative effects (inbreeding depression), if gene flow is limited. In turn this can have

Multi-scale, integrated approaches to understanding the nature and impact of past environmental and climatic change in the archaeological record, and the role of isotope zooarchaeology

Background:The geographic range of the tick Amblyomma americanum, a vector of diseases of public health significance such as ehrlichiosis, has expanded from the southeast of the United States northward during the 20th century. Recently, populations of this tick have been reported to be present close to the Canadian border in Michigan and New York states, but established populations are not known in Canada. Previous research suggests that changing temperature patterns with climate change may influence tick life cycles and permit northward range expansion of ticks in the northern hemisphere.Objectives:We aimed to estimate minimal temperature conditions for survival of A. americanum populations at the northern edge of the tick’s range and to investigate the possibility of range expansion of A. americanum into northern U.S. states and southern Canada in the coming decades.Methods:A simulation model of the tick A. americanum was used, via simulations using climate data from meteorological stations in the United States and Canada, to estimate minimal temperature conditions for survival of A. americanum populations at the northern edge of the tick’s range.Results:The predicted geographic scope of temperature suitability [ annual cumulative degree days (DD) ] included most of the central and eastern U.S. states east of longitude 110°W, which is consistent with current surveillance data for the presence of the tick in this region, as well as parts of southern Quebec and Ontario in Canada. Regional climate model output raises the possibility of northward range expansion into all provinces of Canada from Alberta to Newfoundland and Labrador during the coming decades, with the greatest northward range expansion (up to by the year 2100) occurring under the greenhouse gas (GHG) emissions of Representative Concentration Pathway (RCP) 8.5. Predicted northward range expansion was reduced by approximately half under the reduced GHG emissions of RCP4.5.Discussion:Our results raise the possibility of range expansion of A. americanum into northern U.S. states and southern Canada in the coming decades, and conclude that surveillance for this tick, and the diseases it transmits, would be prudent. https://doi.org/10.1289/EHP5668

Maritime archaeology has a tremendous capacity to engage with climate change science. The field is uniquely positioned to support climate change research and the understanding of past human adaptations to climate change. Maritime archaeological data can inform on environmental shifts and submerged sites can serve as an important avenue for public outreach by mobilizing public interest and action towards understanding the impacts of climate change. Despite these opportunities, maritime archaeologists have not fully developed a role within climate change science and policy. Moreover, submerged site vulnerabilities stemming from climate change impacts are not yet well understood. This article discusses potential climate change threats to maritime archaeological resources, the challenges confronting cultural resource managers, and the contributions maritime archaeology can offer to climate change science. Maritime archaeology’s ability to both support and benefit from climate change science argues its relevant and valuable place in the global climate change dialogue, but also reveals the necessity for our heightened engagement.

This review aims to explore the implications of climate change for breast cancer management and prevention, with a focus on global strategies and interventions that can be applied in various contexts, including South Africa. Climate change has emerged as a significant global health concern, with far-reaching implications for various diseases, including cancer. This systematic review aims to synthesise epidemiological research examining the relationship between climate change and the incidence of breast cancer. We conducted a comprehensive literature search using main search terms, including “breast cancer,” “climate change,” “air pollution,” “water pollution,” “global warming,” and “greenhouse effect,” supplemented by the general term “breast” cancer across multiple databases. Our analysis identified studies that link environmental changes—such as rising temperatures, altered precipitation patterns, and increased exposure to pollutants—with breast cancer risk. Our findings highlight a potential association between climate-related factors, including heat stress, air and water pollution, endocrine-disrupting chemicals, and lifestyle changes influenced by environmental shifts, and the epidemiology of breast cancer. This review underscores the need for an integrated approach that incorporates climate science into public health strategies to mitigate breast cancer risk. By elucidating these connections, we aim to inform policymakers and healthcare professionals about the importance of addressing climate change not just as an environmental issue, but as a pressing determinant of health that may exacerbate cancer incidence, particularly in vulnerable populations. Further research is warranted to elucidate the underlying biological mechanisms and to develop targeted interventions that can address both climate change and its potential health impacts.

Climate Information Needs for Financial Decision Making (Final Report) This Department of Energy workshop award (grant #DE-SC0008480) provided primary support for the American Meteorological Society’s study on climate information needs for financial decision making. The goal of this study was to help advance societal decision making by examining the implications of climate variability and change on near-term financial investments. We explored four key topics: 1) the conditions and criteria that influence returns on investment of major financial decisions, 2) the climate sensitivity of financial decisions, 3) climate information needs of financial decision makers, and 4) potential new mechanisms to promote collaboration between scientists and financial decision makers. Better understanding of these four topics will help scientists provide the most useful information and enable financial decision makers to use scientific information most effectively. As a result, this study will enable leaders in business and government to make well-informed choices that help maximize long-term economic success and social wellbeing in the United States The outcomes of the study include a workshop, which brought together leaders from the scientific and financial decision making communities, a publication of the study report, and a public briefing of the results to the policy community. In addition, we will present the results to the scientific community at the AMS Annual Meeting in February, 2014. The study results were covered well by the media including Bloomberg News and E&E News. Upon request, we also briefed the Office of Science Technology Policy (OSTP) and the Council on Environmental Quality (CEQ) on the outcomes. We presented the results to the policy community through a public briefing in December on Capitol Hill. The full report is publicly available at www.ametsoc.org/cin. Summary of Key Findings The United States invests roughly $1.5 trillion U.S. dollars (USD) in capital assets each year across the public and private sectors (Orszag 2008; United States Census Bureau 2013). Extreme weather events create and exacerbate risks to these financial investments by contributing to: • Direct physical impacts on the investments themselves • Degradation of critical supporting infrastructure • Changes in the availability of key natural resources • Changes to workforce availability or capacity • Changes in the customer base • Supply chain disruptions • Legal liability • Shifts in the regulatory environment • Reductions in credit ratings Even small changes in weather can impact operations in critical economic sectors. As a result, maximizing returns on financial investments depends on accurately understanding and effectively accounting for these risks. Climate variability and change can either exacerbate existing risks or cause new sources of risk to emerge. Managing these risks most effectively will depend on scientific advances and increases in the capacity of financial decision makers to use the scientific knowledge that results. Barriers to using climate information must also be overcome. This study proposes three predefined levels of certainty for communicating about weather and climate risks: 1) possible (i.e., unknown likelihood or less than 50% chance of occurrence), 2) probable (greater than 50% chance of occurrence), and 3) effectively certain (at least 95% chance of occurrence). For example, it is effectively certain that a change in climate will alter weather patterns. It is probable that climate warming will cause increases in the intensity of some extreme events. It is possible that climate change will cause major and widespread disruptions to key planetary life-support services. Key recommendations of this study: 1) Identify climate-related risks and opportunities for financial decision making. 2) Create a framework to translate scientific information in clear and actionable terms for financial decision makers. 3) Analyze existing climate assessments and translate projected impacts into possible, probable, and effectively certain impacts. 4) Improve climate projections with respect to precipitation (timing, amount, and intensity), extreme events, and tails of probability distributions (i.e., low-probability but high-consequence events). 5) Increase spatial resolution of climate projections in order to provide climate information at the scale most relevant to financial investments. 6) Improve projections of the societal consequences of climate impacts through integrated assessments of physical, natural, and social sciences. 7) Create a user-friendly information repository and portal that provides easy access to information relevant to financial decision making. 8) Create and maintain opportunities to bring together financial decision makers, scientists, and service providers. Near-term financial decisions have long-term implications for the United States’ social and economic well-being that depend, in part, on climate variability and change. Investments will be most successful, and will advance the interests of society most effectively, if they are grounded in the best available knowledge & understanding.

We present a continuous ∼7000-year sedimentary record from Lashmars Lagoon, Kangaroo Island (Karti/Karta), southern Australia, a region heavily impacted by drought and bushfires in recent decades. Records such as this are vital to contextualise current climatic and environmental shifts, particularly regarding the interplay between hydroclimate and fire-related disturbances in this ecologically sensitive area. We use high-resolution μX-ray fluorescence core scanning, complemented by bulk organic geochemistry and X-ray diffraction mineralogy of catchment soil and lake sediments to reconstruct past climate and catchment processes. Phases of elevated sediment organic matter content (inferred from high Br and total organic carbon) suggest increased lake freshening and productivity, and coincide with increased chemical weathering (inferred from high Al/K and kaolinite/illite and feldspars), likely reflecting the influence of wetter climates. Conversely, periods of high Ca correlate with biogenic carbonate inputs typical of brackish conditions, which we attribute to drier climates or a marine influence. From 7.0 ka, at the mid-Holocene sea level highstand, until 5.7 ka, we suspect Lashmars Lagoon was under virtually continuous influence from the sea. At 5.7 ka, we interpret the abrupt increase in sediment total organic carbon to reflect the severance of the connection to the sea, allowing organic material to accumulate. This, coupled with evidence of high inferred chemical weathering, suggests the climate was relatively wet at the time. After 5.4 ka, our data point to the establishment of drier conditions until the commencement of wetter climates again at 4.5 ka. From 2.5 ka, however, drier climates prevailed again until present. Notably, the climate changes recorded in the sedimentary sequence at Lashmars Lagoon seem to be linked to the strength of the Leeuwin Current, a current that brings warm tropical waters to southern Australia and demonstrates a teleconnection with the El Niño Southern Oscillation, and may well have been an important driver of rainfall on Kangaroo Island (Karti/Karta) over the past ∼7000 years.

Purpose: This study sought to investigate the impact of climate change on vector-borne diseases in wildlife.
 Methodology: The study adopted a desktop research methodology. Desk research refers to secondary data or that which can be collected without fieldwork. Desk research is basically involved in collecting data from existing resources hence it is often considered a low cost technique as compared to field research, as the main cost is involved in executive’s time, telephone charges and directories. Thus, the study relied on already published studies, reports and statistics. This secondary data was easily accessed through the online journals and library.
 Findings: The findings reveal that there exists a contextual and methodological gap relating to climate change on vector-borne diseases in wildlife. Preliminary empirical review revealed that that environmental shifts, driven by climate change, profoundly influenced the distribution and transmission dynamics of diseases among wildlife populations. Through a comprehensive review of empirical studies, it was found that warmer temperatures, altered precipitation patterns, and extreme weather events expanded vector habitats, increasing disease exposure for wildlife. The research emphasized the importance of interdisciplinary approaches and proactive measures, such as habitat restoration and disease surveillance, to mitigate disease risks and promote ecosystem resilience. Overall, the study highlighted the urgent need to address the interconnected challenges of climate change, vector-borne diseases, and wildlife health to safeguard environmental and human well-being.
 Unique Contribution to Theory, Practice and Policy: The Ecological Niche theory, Disease Ecology theory and One Health theory may be used to anchor future studies on climate change on vector-borne diseases in wildlife. The study provided recommendations that contributed to theory, practice, and policy. From a theoretical perspective, it emphasized the need for interdisciplinary research to understand the complex interactions between climate change, vector populations, and disease transmission. Practically, the study recommended adaptive management strategies, such as habitat restoration and disease surveillance, to mitigate disease risks in wildlife. Policy-wise, it called for integrating climate resilience and biodiversity conservation efforts, along with public education campaigns and international cooperation, to address the transboundary nature of vector-borne disease threats. Overall, these recommendations aimed to build resilience in ecosystems, protect biodiversity, and ensure the health of wildlife populations amidst climate change.