This is a datapaper including microscopically measured data of annual ring widths from the Mediterranean-alpine shrub species Cytisus galianoi (Sierra Nevada, Spain). The dataset will be updated with ...future measurements.
Mediterranean‐alpine plants are exposed to harsh conditions, forcing them to perform with well‐adapted physiological strategies to withstand the dual stressors that arise from winter cold and summer ...drought. Such growth strategies are not yet fully understood, although they gain importance with regard to the resilience of species in the face of ongoing climate variability.
Here, we aimed at understanding shrub growth in a widespread Mediterranean‐alpine species, Cytisus galianoi Talavera & Gibbs. Using long‐term time series of stem diameter change obtained from dendrometer measurements across the species´ range, we were able to characterise its spatiotemporal growth plasticity. Furthermore, separating water‐related fluctuations in stem diameter from irreversible stem increment allowed us to disentangle the species´ seasonal growth patterns. Using fine‐scale measurements of on‐site environmental conditions, we were then able to identify micro‐ecological drivers controlling the species´ growth processes by applying correlation analysis and partial least squares regressions.
We show the species´ adaptation to the spatial heterogeneity across its range for the first time. Our findings highlight that the combination of bimodality and overall high growth plasticity likely allows the species to cover a wide geographical range across alpine areas and over a wide range of weather conditions. We show the environmental control of bimodal growth in C. galianoi, and the importance of pre‐growth environmental control, leading to pronounced carry‐over effects. These lead to a major advantage in resisting adverse growth conditions and adapting to changing conditions.
Synthesis: Overall, our findings improve the understanding of the species´ ecological niche and show that preceding photosynthetic activity helps C. galianoi to perform even under unfavourable conditions in winter and during the active growth phase, challenging the general assumption on the coupling of growth to specific seasons and suggesting that the species is capable of adapting to future climate variability.
These findings improve the understanding of the species' ecological niche and show that preceding photosynthetic activity helps Cytisus galianoi to perform even under unfavourable conditions in winter and during the active growth phase.
Summary
The Mediterranean alpine is one of the most vulnerable ecosystems under future environmental change. Yet, patterns, timing and environmental controls of plant growth are poorly investigated. ...We aimed at an improved understanding of growth processes, as well as stem swelling and shrinking patterns, by examining two common coexisting green‐stemmed shrub species.
Using dendrometers to measure daily stem diameter changes, we separated these changes into water‐related shrinking and swelling and irreversible growth. Implementing correlation analysis, linear mixed effects models, and partial least squares regression on time series of stem diameter changes, with corresponding soil temperature and moisture data as environmental predictors, we found species‐specific growth patterns related to different drought‐adaptive strategies.
We show that the winter‐cold‐adapted species Cytisus galianoi uses a drought tolerance strategy combined with a high ecological plasticity, and is, thus, able to gain competitive advantages under future climate warming. In contrast, Genista versicolor is restricted to a narrower ecological niche using a winter‐cold escape and drought avoidance strategy, which might be of disadvantage in a changing climate.
Pregrowth environmental conditions were more relevant than conditions during growth, controlling the species' resource availability. Thus, studies focusing on current driver constellations of growth may fail to predict a species’ ecological niche and its potential future performance.
Forest degradation occurs in natural World Heritage Sites (WHS) in the Global South despite the implementation of various strategic policies and the World Heritage Convention (WHC) on forest ...protections of the sites and this poses challenges to improving natural heritage sustainability. The current study aims to investigate spatial determinants of forest degradation in the Kilimanjaro WHS, Tanzania, to support strategic policies for forest landscape protection and natural heritage sustainability. Using remotely sensed, Digital Elevation Model, and tourism location data, we performed the supervised classification of satellite images, Digital Elevation, Euclidean distance, and linear regression modeling to identify spatial determinants of forest degradation. Our key findings indicated that while spatial determinants vary with different locations, human (tourism) activities e.g., developments of campsites, picnics, tourist routes, the historical site, and attraction areas are associated with forest degradation in the southern parts of the site. In addition to human activities, natural factors such as low levels of elevation and degrees of slope are associated with forest degradation at the site. However, in the northwest and southwest of the site, high degrees of slope are associated with the degradation. Our findings showed that while bare land surface encroached the primary forest with about 2.88%, moorland vegetation encroached the primary forest with about 16.95%, indicating a large degradation of the primary forest with about 19.83% for the past four decades. The information provided in this study is crucial to support site managers and decision-makers in strategic policies and WHC implementations on forest protection for natural heritage sustainability.
The Tanzanian coast has many remains of medieval Swahili settlements dated between the twelfth and sixteenth centuries C.E. In the same region, Neolithic and Later Stone Age sites have also been ...reported, alongside evidence for Early Iron Working settlements. Swahili culture, and the ruins that can still be seen, have their origins in this rich cultural past. It appears, however, that the present communities along the Tanzanian Swahili coast, and the public, are unaware of this important heritage history. There is a popular belief among them that the origin and influence on the now ruined Swahili settlements came from the Middle East, and it is true that Arab and other travellers described Swahili civilization in their writings. In this article, we explore the communities and researchers’ different perspectives on the origin of the Swahili ruins, focusing on the conservation and management problems this raises. We also analyse the position and role of heritage management institutions in the country towards enhancing community awareness and proper conservation of the ruins. Finally, we propose ways of promoting community awareness of the origin of the Swahili ruins, influencing participation and actions towards their conservation and management.
Climate Change (CC) and variability are global issues that the world has been facing for a long time. Given the recent catastrophic events, such as flooding, erosion, and drought in Nigeria, many ...have questioned institutions’ capacity in managing CC impacts in Nigeria. This study explores emerging institutional barriers of adaptation to CC effects on water resources in Nigeria. The study data were obtained from in-depth interviews with institutional heads from water resources management and emergency management and a review of secondary literature from databases such as Google Scholar, Scopus, and Web of Science. The results show that inadequate hydrological data management, low awareness on how to adapt among the public and decision-makers, financial constraints, no political will to pass important bills into law, and inadequate institutional and legal framework are the main institutional barriers of adaptation to climate change in Nigeria. The study concludes that it is essential to strengthen the institutional and legal system, information management mechanism, public awareness, and participatory water resources management. The implications for further research are presented in the study.
Abstract
Alpine plants are particularly sensitive to climate change, and in the Mediterranean, less frequent winter cold and prolonged summer drought are expected to shift the growth patterns of ...species, altering their range and strategies to cope with these dual climatic stressors. However, adaptive strategies for drought and frost and their impact on performance of species are poorly explored, with critical timescales relevant for growth insufficiently reflected and a focus on a limited set of environmental drivers. Here, we explored the growth processes of two physiologically distinct Mediterranean alpine shrub species:
Cytisus galianoi
(green-stemmed species) and
Astragalus granatensis
(dimorphic species). By measuring the daily stem diameter changes of 26 specimens over six consecutive years (2015–2020) using dendrometers, as well as the corresponding soil temperature and soil moisture conditions, we identified bimodal annual growth patterns (i.e. two phases of growth), water-related timing of growth, and drought- and frost-related environmental constraints. By implementing correlation analyses, linear mixed effects models, and partial least-squares regression, we found pregrowth temperature and moisture drivers to be highly relevant for growth in both species, suggesting a temporal decoupling of growth and resource acquisition. However, the underlying mechanisms were contrasting. While the spring growth of
C. galianoi
was promoted by pregrowth winter conditions, the autumn growth of
A. granatensis
was promoted by pregrowth summer conditions. Thus, resource acquisition is likely to be optimized when the traits of species allow physiological activity at high gain and low costs, i.e. when adaptive mechanisms reduce resource consumption to cope with frost and drought. This is during winter for frost-tolerant green-stemmed species and during summer for drought-avoidant dimorphic species, leading to species-specific time windows of growth. Understanding these species-specific growth mechanisms contributes to answering the overarching question of when and how woody plants grow and helps in understanding their adaptability to future climate variability, particularly in sensitive alpine environments, where plant species are evolutionally adapted to physical peculiarities and reach their low-temperature limit.
Abstract
Under climate change, cold-adapted alpine ecosystems are turning into hotspots of warming. However, the complexity of driving forces of growth, associated biomass gain and carbon storage of ...alpine shrubs is poorly understood. We monitored alpine growth mechanisms of six common shrub species across contrasting biomes, Mediterranean and tundra, using 257 dendrometers, recording stem diameter variability at high temporal resolution. Linking shrub growth to on-site environmental conditions, we modelled intra-annual growth patterns based on distributed lag non-linear models implemented with generalized additive models. We found pronounced bimodal growth patterns across biomes, and counterintuitively, within the cold-adapted biome, moisture, and within the drought-adapted biome, temperature was crucial, with unexpected consequences. In a warmer world, the Mediterranean alpine might experience strong vegetation shifts, biomass gain and greening, while the alpine tundra might see less changes in vegetation patterns, minor modifications of biomass stocks and rather browning.
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