Characterisation of Vegetation Response to Climate Change: A Review

Assessing the Implications of Deforestation and Climate Change on Rural Livelihood in Ghana: a Multidimensional Analysis and Solution-Based Approach

The Ashanti region in Ghana, abundant in natural resources such as forests and vegetation biomes, significantly supports the livelihoods of a significant portion of the population. The sustainable management of forest resources remains a significant challenge to achieving environmental and economic growth and poverty alleviation. The study aims to identify the drivers of deforestation and assess its impact on the livelihoods of the poor and vulnerable communities in the Ashanti region. The study utilized qualitative and space-based data to examine the patterns of vegetation cover and deforestation from 2000 to 2020. The results revealed moderate to sparse vegetation in Ashanti from 2002, 2005, 2011, 2015, 2017, and 2018, with no vegetation in the northcentral part, attributed to climate change, agricultural practices, government policies, and deforestation-related disasters. The study found a significant correlation (R² = 0.8197) between years and deforestation areas, especially in 2018 at around 16,000 Sqkm, indicating an exponential increase with severe implications for sustainable livelihoods. Much of these changes were reflected in 2020 with a high peak of deforestation towards the southeastern parts of the region. Additionally, the results show that the poor groups are not passive actors but are actively involved in identifying systems and processes through which to build their adaptive capacity and resilience to environmental and climate change-induced changes. The findings provide evidence-based and all-inclusive approaches that would encourage vulnerable and marginalized groups to participate in the co-production and co-creation of policies and strategies. This outcome is geared towards transformative and sustainable communities while ensuring efficient and effective response and recovery capacities of deforested lands.

Geospatial Mapping and Meteorological Flood Risk Assessment: A Global Research Trend Analysis

Flooding is a global threat causing significant economic and environmental damage, necessitating a policy response and collaborative strategy. This study assessed global research trends and advances in geospatial and meteorological flood risk assessment (G_MFRA), considering the ongoing debate on flood risk management and adaptation strategies. A total of 1872 original articles were downloaded in BibTex format using the Web of Science (WOS) and Scopus databases to retrieve G_MFRA studies published from 1985 to 2023. The annual growth rate of 15.48% implies that the field of G_MFRA has been increasing over time during the study period. The analysis of global trends in flood risk research and practice highlights the key themes, methodologies, and emerging directions. There exists a notable gap in data and methodologies for flood risk assessment studies between developed and developing countries, particularly in Africa and South America, highlighting the urgency of coordinated research efforts and cohesive policy actions. The challenges identified in the body of extant literature include technical expertise, complex communication networks, and resource constraints associated with the application gaps of the study methodologies. This study advocates for a holistic research approach to flood disaster management through ecosystem-based adaptation that underpins the Sustainable Development Goals to develop innovative flood techniques and models with the potential to influence global decision-making in the G_MFRA domain. Addressing these global challenges requires a networked partnership between the research community, institutions, and countries.

Factors Influencing the Variation of Plants' Cardinal Temperature: A Case Study in Iran

The establishment and spread of plants in their native or alien geographical ranges are determined by their germination. This study investigated the impact of different factors on variations in cardinal temperatures. We used the lm procedure and measured the effect size by the Eta-square approach to find the association of different factors (species, ecotypes, origin (native/alien), year, and life cycle) with the cardinal temperatures of 31 species. Our results showed that the base, optimum, and maximum temperatures responded differently to these factors. The base temperature was less impacted by ecotypes compared with the optimum and maximum temperatures, whereas the species had a higher impact on the variation in the base temperature. The effect of the origin of weedy plants on the base temperature was higher than the optimum and maximum temperatures. The effect of the year on the optimum temperature was more prominent than that on the base and maximum temperatures. The results confirmed that weedy alien plants preferred high and narrow ranges of base, optimum, and maximum temperatures and probably will be more problematic in summer crops. The results indicate that alien plants can benefit from warmer conditions in invaded areas at the germination stage. These findings lay the foundation for further studies to elucidate which factors are more important.

Climate Change Potentially Leads to Habitat Expansion and Increases the Invasion Risk of Hydrocharis (Hydrocharitaceae)

Climate change is a crucial factor impacting the geographical distribution of plants and potentially increases the risk of invasion for certain species, especially for aquatic plants dispersed by water flow. Here, we combined six algorithms provided by the biomod2 platform to predict the changes in global climate-suitable areas for five species of Hydrocharis (Hydrocharitaceae) (H. chevalieri, H. dubia, H. laevigata, H. morsus-ranae, and H. spongia) under two current and future carbon emission scenarios. Our results show that H. dubia, H. morsus-ranae, and H. laevigata had a wide range of suitable areas and a high risk of invasion, while H. chevalieri and H. spongia had relatively narrow suitable areas. In the future climate scenario, the species of Hydrocharis may gain a wider habitat area, with Northern Hemisphere species showing a trend of migration to higher latitudes and the change in tropical species being more complex. The high-carbon-emission scenario led to greater changes in the habitat area of Hydrocharis. Therefore, we recommend strengthening the monitoring and reporting of high-risk species and taking effective measures to control the invasion of Hydrocharis species.

Long-Term Dynamics and Response to Climate Change of Different Vegetation Types Using GIMMS NDVI3g Data over Amathole District in South Africa

Monitoring vegetation dynamics is essential for improving our understanding of how natural and managed agricultural landscapes respond to climate variability and change in the long term. Amathole District Municipality (ADM) in Eastern Cape Province of South Africa has been majorly threatened by climate variability and change during the last decades. This study explored long-term dynamics of vegetation and its response to climate variations using the satellite-derived normalized difference vegetation index from the third-generation Global Inventory Modeling and Mapping Studies (GIMMS NDVI3g) and the ERA5-Land global reanalysis product. A non-parametric trend and partial correlation analyses were used to evaluate the long-term vegetation changes and the role of climatic variables (temperature, precipitation, solar radiation and wind speed) during the period 1981–2015. The results of the ADM’s seasonal NDVI3g characteristics suggested that negative vegetation changes (browning trends) dominated most of the landscape from winter to summer while positive (greening) trends dominated in autumn during the study period. Much of these changes were reflected in forest landscapes with a higher coefficient of variation (CV ≈ 15) than other vegetation types (CV ≈ 10). In addition, the pixel-wise correlation analyses indicated a positive (negative) relationship between the NDVI3g and the ERA5-Land precipitation in spring–autumn (winter) seasons, while the reverse was the case with other climatic variables across vegetation types. However, the relationships between the NDVI3g and the climatic variables were relatively low (R < 0.5) across vegetation types and seasons, the results somewhat suggest the potential role of atmospheric variations in vegetation changes in ADM. The findings of this study provide invaluable insights into potential consequences of climate change and the need for well-informed decisions that underpin the evaluation and management of regional vegetation and forest resources.

Assessing the Sensitivity of Vegetation Cover to Climate Change in the Yarlung Zangbo River Basin Using Machine Learning Algorithms

Vegetation is a key indicator of the health of most terrestrial ecosystems and different types of vegetation exhibit different sensitivity to climate change. The Yarlung Zangbo River Basin (YZRB) is one of the highest basins in the world and has a wide variety of vegetation types because of its complex topographic and climatic conditions. In this paper, the sensitivity to climate change for different vegetation types, as reflected by the Normalized Difference Vegetation Index (NDVI), was assessed in the YZRB. Three machine learning models, including multiple linear regression, support vector machine, and random forest, were adopted to simulate the response of each vegetation type to climatic variables. We selected random forest, which showed the highest performance in both the calibration and validation periods, to assess the sensitivity of the NDVI to temperature and precipitation changes on an annual and monthly scale using hypothetical climatic scenarios. The results indicated there were positive responses of the NDVI to temperature and precipitation changes, and the NDVI was more sensitive to temperature than to precipitation on an annual scale. The NDVI was predicted to increase by 1.60%–4.68% when the temperature increased by 1.5 °C, while it only changed by 0.06%–0.24% when the precipitation increased by 10% in the YZRB. Monthly, the vegetation was more sensitive to temperature changes in spring and summer. Spatially, the vegetation was more sensitive to temperature increases in the upper and middle reaches, where the existing temperatures were cooler. The time-lag effects of climate were also analyzed in detail. For both temperature and precipitation, Needleleaf Forest and Broadleaf Forest had longer time lags than those of other vegetation types. These findings are useful for understanding the eco-hydrological processes of the Tibetan Plateau.

A bibliometric review of vegetation response to climate change

Global assessment of vegetation response to climate change (VRCC) studies was conducted to reveal the research evolution, current research hotspots and better understanding of dominant themes in VRCC areas of research from 1992 to 2019 through the use of bibliometrics. A total of 186 articles with the search term "Vegetation response to Climate change" were retrieved using the Web of Science (WOS) database. The annual growth rate of 10.3% connotes that research on VRCC has been increasing over time during the survey period. Average citations per article experienced many fluctuations over the years rather than maintaining the same growth rate, which connotes that this field of research reached was unstable in terms of average total citation per document. Results show that China ranked first followed by the USA and the UK, and this shows the dominance of these countries on VRCC studies over the years in review. Results from corresponding authors' nationalities show that multiple-country publications are relatively low compared to articles from single-country publications which showed a dominant trend. Hence, we can infer that most studies on VRCC were sustained by single-country publications. Results from this study revealed top-cited articles, the top global distribution of documents, academic collaboration, most relevant keywords and Word TreeMap of high-frequency keywords. The findings of this study show that "temperature" is in a central position in all keywords with the largest significant appearance in the field. In conclusion, the findings from this study may be applicable for planning and managing vegetation and forest ecosystem research and provide hints for future development.

Agricultural Drought and Its Potential Impacts: Enabling Decision-Support for Food Security in Vulnerable Regions

Increasing demand for food and environmental stressors are some of the most challenging problems that human societies face today and these have encouraged new studies to examine drought impacts on food production. Seeking to discuss these important issues in the South African context, this study analyzed the impacts of drought on food security in one of the country's largest commercial agricultural land (Free State Province). Earth observation and crop data were acquired from Application for Extracting and Exploring Analysis Ready Samples (AppEEARS) and GrainSA databases, respectively for years 2011/2012–2020/2021 over Free State Province. Two crops namely, maize and sorghum were obtained from the database and analyzed accordingly to quantify drought impacts on the two crops. The result reveals that the years 2015 and 2018 were affected by extreme drought events (&lt;10%) where the majority of the study area was impacted. Years 2011, 2016, 2018, and 2019 were severely affected by drought (&gt;30%) and impacted the agricultural sector in the study area. Findings further revealed that maize production observed the lowest recorded in the year 2014 and 2015 with about 223,600 and 119,050 tons, respectively. More so, results further showed that sorghum production recorded the lowest production in years 2019, 2016, and 2015 with about 23,600, 24,640, and 24,150 tons, in that order during the period of study. The results confirm the impacts of drought on maize and sorghum productions in the year 2015 and other years that recorded the lowest productions during drought years. This development might have impacted food security in the study area, and this outcome will enable decision-making bodies on food security to enhance improved strategy in vulnerable areas.

Water, Energy and Food Nexus: Policy Relevance and Challenges

Connections between water, food, and energy are at the center of long-term economic and environmental development and protection. Water, energy and food are the keys to economic input and a necessary component of economic progress. The adoption of water management policies and techniques that support the sustainable use of resources while promoting economic growth is becoming an important concern, particularly in countries where water and food scarcity are critical or problematic. This study aimed at evaluating Water, Energy and Food Nexus (WEF), and as well as challenges of its implementation. This study looked at the articles that were published on WEF nexus between 2015 and 2021 acquired from the Scopus database, focusing on gaps and implementations. I searched for relevant key terms in the database and the search found hundreds of articles on WEF, of which 28 articles were relevant to the scope of the study and these articles were downloaded as BibTeX file for the analysis and the analysis was done using R programming. A number of insights and implications were identified based on the analyses of the findings of the reviewed research in order to increase the policy relevance and overall implementation of the WEF nexus by public policy and decision-making institutions. To boost uptake of the findings, the study gives an outline of the primary constraints and challenges that restrict the policy relevance of the WEF nexus.

Drought: A Common Environmental Disaster

Droughts have been identified as an environmental hazard by environmentalists, ecologists, hydrologists, meteorologists, geologists, and agricultural experts. Droughts are characterised by a decrease in precipitation over a lengthy period, such as a season or a year, and can occur in virtually all climatic zones, including both high and low rainfall locations. This study reviewed drought-related impacts on the environment and other components particularly, in South Africa. Several attempts have been made using innovative technology such as earth observation and climate information as recorded in studies. Findings show that the country is naturally water deficient, which adds to the climate fluctuation with the average annual rainfall in South Africa being far below the global average of 860 mm per year. Drought in South Africa’s Western Cape Province, for example, has resulted in employment losses in the province’s agriculture sector. According to the third quarterly labor force survey from 2017, the agricultural industry lost almost 25,000 jobs across the country. In the Western Cape province, about 20,000 of these were lost which has a direct impact on income generation. Many of these impacts were linked to drought events.