Timescale Effects of Radial Growth Responses of Two Dominant Coniferous Trees on Climate Change in the Eastern Qilian Mountains

To explore the difference in the response of the radial growth of Pinus tabulaeformis and Picea crassifolia on different timescales to climate factors in the eastern part of Qilian Mountains, we used dendrochronology to select four different timescales (day, pentad (5 days), dekad (10 days), and month) for exploration. The primary conclusions were as follows: (1) According to an investigation of the dynamic correlations between radial growth and climate conditions, drought during the growing season has been the dominant limiting factor for radial growth across both species in recent decades; (2) climate data at the dekad scale are best for examining the correlations between radial growth and climate variables; and (3) based on basal area increment, P. tabuliformis in the study area showed a trend of first an increase and then a decrease, while P. crassifolia showed a trend of continuous increase (BAI). As the climate continues to warm in the future, forest ecosystems in arid and semi-arid areas will be more susceptible to severe drought, which will lead to a decline in tree growth, death, and community deterioration. As a result, it is critical to implement appropriate management approaches for various species based on the peculiarities of their climate change responses.

Livestock's Near-Term Climate Impact and Mitigation Policy Implications

Human consumption of livestock remains a marginal issue in climate change debates, partly due to the IPCC's arbitrary adoption of 100-year global warming potential framework to compare different emissions, blinding us to the significance of shorter-term emissions, namely methane. Together with the gas it reacts to form - tropospheric ozone - methane has been responsible for 37% of global warming since 1750, yet its atmospheric life is just 10 years. Neglecting its role means overlooking powerful mitigation opportunities. The chapter discusses the role of livestock, the largest anthropogenic methane source, and the need to include reduced meat consumption in climate change responses. Looking beyond the conventional focus on the consumer, we point to some underlying challenges in addressing the meat-climate relationship, including the climate science community's reluctance to adopt a short-term focus in its climate projections. Policy options are presented.

Digitalization to Achieve Technology Innovation in Climate Technology Transfer

Technology Innovation has the potential to play a strategic role in improving the effectiveness and efficiency of national efforts to address climate change. The United Nations (UN) Climate Technology Centre and Network (CTCN) is mandated to support developing countries’ climate change responses through innovative technologies to achieve the goals of the Paris Agreement. In order to enhance the role of the CTCN as an innovation matchmaker, it is important to explore and leverage the implementation potential of new digital technologies and their transformational impact. Thus, in this research, to engage digitalization as an innovative tool with the environment, we first explored digitalization during the climate technology transfer processes by comprehensively reviewing CTCN Technical Assistance (Digitalization Technical Assistance, D-TA) activities in three climate sectors of risk prediction, policy decision making, and resource optimization. Then, by applying analytical methodologies of in-depth interviews with major digital-climate stakeholders and a staged model for technology innovation, we propose future strategies for enhancing the role of CTCN as an innovation matchmaker in the three digitalization cases of digital collection, digital analysis, and digital diffusion.

Land use and life history constrain adaptive genetic variation and reduce the capacity for climate change adaptation in turtles

Background Rapid anthropogenic climate change will require species to adapt to shifting environmental conditions, with successful adaptation dependent upon current patterns of genetic variation. While landscape genomic approaches allow for exploration of local adaptation in non-model systems, most landscape genomics studies of adaptive capacity are limited to exploratory identification of potentially important functional genes, often without a priori expectations as to the gene functions that may be most important for climate change responses. In this study, we integrated targeted sequencing of genes of known function and genotyping of single-nucleotide polymorphisms to examine spatial, environmental, and species-specific patterns of potential local adaptation in two co-occuring turtle species: the Blanding’s turtle (Emydoidea blandingii) and the snapping turtle (Chelydra serpentina). Results We documented divergent patterns of spatial clustering between neutral and putatively adaptive genetic variation in both species. Environmental associations varied among gene regions and between species, with stronger environmental associations detected for genes involved in stress response and for the more specialized Blanding’s turtle. Land cover appeared to be more important than climate in shaping spatial variation in functional genes, indicating that human landscape alterations may affect adaptive capacity important for climate change responses. Conclusions Our study provides evidence that responses to climate change will be contingent on species-specific adaptive capacity and past history of exposure to human land cover change.

Response of Northern Populations of Black Spruce and Jack Pine to Southward Seed Transfers: Implications for Climate Change

A variety of responses to climate change have been reported for northern tree populations, primarily from tree-ring and satellite-based studies. Here we employ provenance data to examine growth and survival responses of northern populations (defined here as those occurring north of 52° N) of black spruce (Picea mariana) and jack pine (Pinus banksiana) to southward seed transfers. This space for time substitution affords insights into potential climate change responses by these important northern tree species. Based on previous work, we anticipated relatively flat response curves that peak at much warmer temperatures than those found at seed source origin. These expectations were generally met for growth-related responses, with peak growth associated with seed transfers to environments with mean annual temperatures 2.2 and 3.6 °C warmer than seed source origin for black spruce and jack pine, respectively. These findings imply that northern tree populations harbor a significant amount of resilience to climate warming. However, survival responses told a different story, with both species exhibiting reduced survival rates when moved to warmer and drier environments. Together with the growth-based results, these findings suggest that the warmer and drier conditions expected across much of northern Canada under climate change may reduce survival, but surviving trees may grow at a faster rate up until a certain magnitude of climate warming has been reached. We note that all relationships had high levels of unexplained variation, underlining the many factors that may influence provenance study outcomes and the challenges in predicting tree responses to climate change. Despite certain limitations, we feel that the provenance data employed here provide valuable insights into potential climate change outcomes for northern tree populations.

Creating a climate of change in the City of Johannesburg: Co-learning to adapt to climate change

Climate change is one of the multiple stressors facing African cities; these cities are responding by developing climate change action plans including adaptation and mitigation policies. Effectively mainstreaming climate change in city plans and operations and moving from ambition to implementation is complex. Multi-actor engagement, transdisciplinary knowledge interactions, co-designing and sustained co-learning are often required in such planning and action contexts. In this paper, we trace and reflect on the process of developing an adaptation planning process for the City of Johannesburg, South Africa. Given shortcomings of the previous adaptation responses attempted in the City, specifically that of poor uptake, we trialled a more intentional and directly designed, formative and interventionist approach using Cultural Historical Activity Theory (CHAT). We reflect on what we as a research team and City officials learnt in this process. Our findings emphasise that exploring the local context remains critical in understanding and surfacing tensions with potential climate change responses. Failure to be mindful of such issues will likely result in mere compliance, and potentially, maladaptation. Contrary to experiences in other South African settings, rather than attempting to engage all actors simultaneously, our experience suggests that working with a core group initially, before expanding the circle of actors, is needed. These actors serve as mediators and pivotal actors for learning and change, and, with appropriate authority and passion, can drive, coalesce, and potentially re-enthuse waning interest from within. They leverage already existing trust relationships and strengthen participation throughout the process. Combined, these factors are critical for ensuring implementation and legacy.

Comprehensive leaf size traits dataset for seven plant species from digitised herbarium specimen images covering more than two centuries

Morphological leaf traits are frequently used to quantify, understand and predict plant and vegetation functional diversity and ecology, including environmental and climate change responses. Although morphological leaf traits are easy to measure, their coverage for characterising variation within species and across temporal scales is limited. At the same time, there are about 3100 herbaria worldwide, containing approximately 390 million plant specimens dating from the 16th to 21st century, which can potentially be used to extract morphological leaf traits. Globally, plant specimens are rapidly being digitised and images are made openly available via various biodiversity data platforms, such as iDigBio and GBIF. Based on a pilot study to identify the availability and appropriateness of herbarium specimen images for comprehensive trait data extraction, we developed a spatio-temporal dataset on intraspecific trait variability containing 128,036 morphological leaf trait measurements for seven selected species. After scrutinising the metadata of digitised herbarium specimen images available from iDigBio and GBIF (21.9 million and 31.6 million images for Tracheophyta; accessed date December 2020), we identified approximately 10 million images potentially appropriate for our study. From the 10 million images, we selected seven species (Salix bebbiana Sarg., Alnus incana (L.) Moench, Viola canina L., Salix glauca L., Chenopodium album L., Impatiens capensis Meerb. and Solanum dulcamara L.) , which have a simple leaf shape, are well represented in space and time and have high availability of specimens per species. We downloaded 17,383 images. Out of these, we discarded 5779 images due to quality issues. We used the remaining 11,604 images to measure the area, length, width and perimeter on 32,009 individual leaf blades using the semi-automated tool TraitEx. The resulting dataset contains 128,036 trait records. We demonstrate its comparability to trait data measured in natural environments following standard protocols by comparing trait values from the TRY database. We conclude that the herbarium specimens provide valuable information on leaf sizes. The dataset created in our study, by extracting leaf traits from the digitised herbarium specimen images of seven selected species, is a promising opportunity to improve ecological knowledge about the adaptation of size-related leaf traits to environmental changes in space and time.

The Role of Extracellular Carbonic Anhydrase in Biogeochemical Cycling: Recent Advances and Climate Change Responses

Climate change has been predicted to influence the marine phytoplankton community and its carbon acquisition strategy. Extracellular carbonic anhydrase (eCA) is a zinc metalloenzyme that catalyses the relatively slow interconversion between HCO3− and CO2. Early results indicated that sub-nanomolar levels of eCA at the sea surface were sufficient to enhance the oceanic uptake rate of CO2 on a global scale by 15%, an addition of 0.37 Pg C year−1. Despite its central role in the marine carbon cycle, only in recent years have new analytical techniques allowed the first quantifications of eCA and its activity in the oceans. This opens up new research areas in the field of marine biogeochemistry and climate change. Light and suitable pH conditions, as well as growth stage, are crucial factors in eCA expression. Previous studies showed that phytoplankton eCA activity and concentrations are affected by environmental stressors such as ocean acidification and UV radiation as well as changing light conditions. For this reason, eCA is suggested as a biochemical indicator in biomonitoring programmes and could be used for future response prediction studies in changing oceans. This review aims to identify the current knowledge and gaps where new research efforts should be focused to better determine the potential feedback of phytoplankton via eCA in the marine carbon cycle in changing oceans.

Interindividual plasticity in metabolic and thermal tolerance traits from populations subjected to recent anthropogenic heating

To better understand temperature's role in the interaction between local evolutionary adaptation and physiological plasticity, we investigated acclimation effects on metabolic performance and thermal tolerance among natural Fundulus heteroclitus (small estuarine fish) populations from different thermal environments. Fundulus heteroclitus populations experience large daily and seasonal temperature variations, as well as local mean temperature differences across their large geographical cline. In this study, we use three populations: one locally heated (32°C) by thermal effluence (TE) from the Oyster Creek Nuclear Generating Station, NJ, and two nearby reference populations that do not experience local heating (28°C). After acclimation to 12 or 28°C, we quantified whole-animal metabolic (WAM) rate, critical thermal maximum (CT max ) and substrate-specific cardiac metabolic rate (CaM, substrates: glucose, fatty acids, lactate plus ketones plus ethanol, and endogenous (i.e. no added substrates)) in approximately 160 individuals from these three populations. Populations showed few significant differences due to large interindividual variation within populations. In general, for WAM and CT max , the interindividual variation in acclimation response (log 2 ratio 28/12°C) was a function of performance at 12°C and order of acclimation (12–28°C versus 28–12°C). CT max and WAM were greater at 28°C than 12°C, although WAM had a small change (2.32-fold) compared with the expectation for a 16°C increase in temperature (expect 3- to 4.4-fold). By contrast, for CaM, the rates when acclimatized and assayed at 12 or 28°C were nearly identical. The small differences in CaM between 12 and 28°C temperature were partially explained by cardiac remodeling where individuals acclimatized to 12°C had larger hearts than individuals acclimatized to 28°C. Correlation among physiological traits was dependent on acclimation temperature. For example, WAM was negatively correlated with CT max at 12°C but positively correlated at 28°C. Additionally, glucose substrate supported higher CaM than fatty acid, and fatty acid supported higher CaM than lactate, ketones and alcohol (LKA) or endogenous. However, these responses were highly variable with some individuals using much more FA than glucose. These findings suggest interindividual variation in physiological responses to temperature acclimation and indicate that additional research investigating interindividual may be relevant for global climate change responses in many species.