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Planting and replanting: Continuity and change over four decades of forest restoration in Himachal Pradesh, India
Get PDFSocietal Impact StatementIndia has a long history of planting trees to restore ecosystem services providing an opportunity to evaluate long-term ecosystem restoration processes. We show that these programs have shifted over time in response to public demands as well as through changes in the government's vision for forests. These shifts point towards opportunities and limits for political responsiveness in the design and implementation of restoration programs. Independent evaluations have shown that the tree planting programs we study often fail to achieve their goals, raising questions about their benefits, and risks from positioning tree planting as a panacea for social and environmental problems.Summary Aims: Interest in forest restoration has increased in recent years with the goal of increasing carbon storage, protecting biodiversity, and improving the delivery of ecosystem services to aid rural livelihoods. However, there is little systematic analysis of how this trend relates to broader histories of landscape interventions. Methods: We analyze a dataset comprising 36 years of government plantation records from the forest department of the Indian Himalayan state of Himachal Pradesh. Findings: Restoration-oriented tree planting peaked in the 1980s and 1990s with heavy domestic funding. Counter to dominant policy narratives, most plantation programs did not formally involve the participation of local people and were not funded by donors or carbon markets. Over time, planting shifted away from commercial timber species towards a more diverse set of native broadleaf species, reflecting local preferences for the production of firewood, fodder, and other non-timber forest products and ecosystem services as well as changing conceptions by government agencies about what and who a forest is meant to serve. Over time, the number of programs sponsoring tree planting has proliferated, reflecting the ways that tree planting has been framed as the solution to a growing number of problems, ranging from poverty alleviation to climate adaptation. Conclusion: The current global focus on forest restoration and nature-based climate solutions represents a reframing of long-existing policies and programs in this region. As with past policy changes, restoration practices are likely to be influenced by long-term histories, entrenched practices, and local political influences
Stronger effect of temperature on body growth in cool than in warm populations suggests lack of local adaptation
Get PDFBody size is a key functional trait that has declined in many biological communities, partly due to changes in individual growth rates in response to climate warming. However, our understanding of growth responses in natural populations is limited by relatively short time series without large temperature contrasts and unknown levels of adaptation to local temperatures across populations within species. In this study, we collated back-calculated length-at-age data for the fish Eurasian perch Perca fluviatilis from 10 populations along the Baltic Sea coast between 1953 and 2015 (142 023 length-at-age measurements). We fitted individual growth trajectories using the von Bertalanffy growth equation, and reconstructed local temperature time series using generalized linear mixed models fitted to three data sources. Leveraging a uniquely large temperature contrast due to climate change and artificial heating from nuclear power plants in two of the examined populations, we then estimated population-specific and global (across populations) growth-temperature relationships using Bayesian mixed models, and evaluated whether populations are locally adapted to environmental temperatures. We found little evidence for local adaptation of body growth. Populations did not exhibit unique optimum growth temperatures nor unique growth rates at a common reference temperature. Instead, population-specific curves mapped onto a global curve, resulting in body growth increasing with warming in cold populations but decreasing in one of the warmer populations. Understanding whether the effects of warming on growth are population-specific is critical for generalizing predictions of climate impacts on body size, which affects multiple levels of biological organization from individuals to ecosystem functioning
Integrative Genomics Refines Tissues, Candidate Genes and Putative Regulatory Links Involved in the Humic Adaptation of Keystone Freshwater Fish
Get PDFAlthough population genomics approaches have been successful in identifying regions of the genome shaped by natural selection, progress in dissecting the molecular mechanisms of adaptive variants and traits has been slow. By integrating multi-tissue (gill, spleen, olfactory rosette, whole eye, and liver) transcriptomes from 16 wild Eurasian perch (Perca fluviatilis) populations and previously identified footprints of selection, we prioritise tissues, candidate genes, and putative SNP-gene expression associations potentially involved in the humic adaptation of this keystone freshwater fish. Over 5000 differentially expressed genes (DEGs) were discovered across the five tissues. A significant excess of outlier SNPs among DEGs found in the gill and spleen tissues indicated their potential involvement in humic adaptation. Next, we identified 2640 cis-eQTLs, and observed significant enrichment of outliers among expression-associated SNPs (eSNPs) in spleen and olfactory rosette tissues, as well as in all tissues combined. Several eQTLs were found in the regions showing the strongest signals of selection, which also harboured DEGs (chr. 5: PLAGL2, chr. 7: PPP1R8, TCHH). Thus, our integrative analyses enabled us to pinpoint specific organs that potentially play a key role in adaptation, prioritise candidate genes under divergent selection based on their expression patterns, and identify links between SNPs and transcript abundance variation. We expect that by combining evolutionary and functional genomics perspectives this work provides a practical framework for understanding the genetic basis of phenotypic diversification and adaptation across a wide range of species
Fungal guild interactions slow decomposition of boreal forest pine litter and humus
Get PDFEricaceous understory shrubs and ericoid mycorrhizal fungal communities are ubiquitous in boreal forests, and their interactions with ectomycorrhizal and saprotrophic fungi may determine organic matter dynamics in forest soils. We followed decomposition of pine needle litter and mor-layer humus over 3 yr in a factorial shrub removal- and pine root exclusion experiment in an old-growth Scots pine (Pinus sylvestris) forest, to evaluate effects of fungal guilds on mass loss. Litter mass loss was 23% greater when ectomycorrhizal fungi were excluded suggesting increased saprotrophic activity, independently of ericoid shrub presence. However, this 'Gadgil effect' was only found after 17 months following a summer drought. By contrast, humus mass loss was overall stimulated by ectomycorrhizal fungi, while ericoid mycorrhizal shrubs appeared to counteract this effect, potentially caused by simultaneous addition of recalcitrant organic matter and inhibition of ectomycorrhizal decomposers. We conclude that competitive saprotrophic-ectomycorrhizal fungal interactions may slow early-stage litter decomposition, but this effect was small and inconsistent. Furthermore, interactions between ecto- and ericoid mycorrhizal guild members appear to determine the late-stage organic matter balance of boreal forest humus
Birdwatching in the digital age: how technologies shape relationships to birds
Get PDFAdvances in technologies have affected birdwatching and its popularization through time. To better understand how, we expose ways by which today's digital technology-typically taken for granted-shapes the social practices of birdwatching, which shifts human-bird relationships and has consequences for birds themselves. Starting in the transition from analogue to digital, we highlight how technologies have functioned to enhance human abilities and create connections among people, organizations, and places. We then analyze contemporary digital technologies (e.g., digital cameras, social media, and online biodiversity monitoring platforms), demonstrating how their entry into birdwatching practices reformulates the interests and power of various actors. Such processes affect the experience of birdwatching, its perceived benefits, the organization of birdwatching communities, and how birds are seen. To conclude, we address societal and ethical implications of digital technologies in birdwatching, focusing on their democratizing potential, as well as concerns over privacy, data ownership, and uneven digital engagement
Balancing hydropower production and ecology - ecological impacts, mitigation measures, and programmatic monitoring.
Get PDFHydropower is a vital renewable energy source but has substantial ecological impacts on rivers, lakes, and surrounding ecosystems. It alters hydrogeomorphology, disrupts connectivity, and changes water physicochemical properties such as temperature and dissolved gas concentrations. Historically, the environmental impact has been of less concern compared to energy production, and there is an urgent need to adapt hydropower production to reduce impacts on aquatic ecosystems. While various mitigation measures exist, a systematic understanding of their efficiency is lacking. Here, we extensively review both the environmental effects of hydropower and the scientific base for mitigation measures. We then list key abiotic and biological candidates for systematic monitoring before outlining a programmatic monitoring approach to evaluate the efficiency of mitigation measures. This programmatic monitoring approach involves monitoring packages based on specific mitigation measures. A set of abiotic parameters and biological indicators are monitored with standardized methods and monitoring designs over the long-term and at several sites, covering different river types and hydropower configurations. The proposed program serves to inform ongoing and future remedial measures, expand our mechanistic understanding of the ecological effects, facilitate knowledge transfer, and allow for more reductionist monitoring approaches outside of the program
Berries to Go: Distinct Passerine Spring Migration Frugivory at a Main Mediterranean Stopover Site
No full textMany animals show phenotypic flexibility in response to a seasonal environment. Especially migratory birds have been found to exhibit striking physiological and behavioural adaptations to overcome the negative impacts of environmental seasonality. Migratory songbirds often show extreme changes in feeding physiology and behaviour before embarking on a migratory flight, including predominantly insectivorous species switching their diet preference to a frugivorous one before autumn migration. Yet, little is known about frugivory during spring migration in temperate zones. In this paper, we report that five songbird species forage on the fruits of two Mediterranean plants, Prasium majus and Rhamnus alaternus, during spring stopover in the Tyrrhenian Sea. Analyses of faecal content showed that fruits of P. majus were generally preferred, with garden warblers (Sylvia borin) having the highest percentage of faecal samples containing seeds of both plants. Availability of ripe P. majus fruits increased over the sampling season and correlated positively with the number of faecal samples containing seeds. Our findings reveal a relevance of fruit at a temperate zone stopover site during spring migration for five passerine species. Frugivory during spring migration may represent an easy means for birds to acquire macronutrients, micronutrients and water. This may be especially important at resource-poor stopover sites and may aid birds' continuation of the northward flight towards their breeding grounds in a timely manner
Fungal diversity in wood of living trees is higher in oak than in beech, maple or linden, and is affected by tree size and climate
No full textFungi are abundant in wood of living trees, but few studies have compared the diversity of fungi among different tree species and trees of varying age and size, aspects of importance for conservation planning. We investigated if fungal species richness and species composition in wood vary significantly among the temperate broadleaf tree species beech (Fagus sylvatica), linden (Tilia cordata), Norway maple (Acer platanoides) and pedunculate oak (Quercus robur). Each tree species was represented by four stem size classes, and the total sample included 240 trees in southern Norway. Wood cores were collected from individual trees and fungal DNA was amplified using ITS2 rRNA as a marker and subjected to high-throughput sequencing. In total, we detected 1156 fungal OTUs. Oaks had significantly higher richness of fungal OTUs than any of the other tree species and harboured unique communities. Further, oak hosted most species-specific Indicator species (39) and was the only species to host Red-Listed fungal species (five). The circumference (proxy for age) did not significantly affect neither OTU richness nor its overall composition. However, several individual Red List and Indicator species were found only in trees of the largest size class. There was a significant effect of bioclimatic section on species composition. Our results emphasize the important roles of oaks and to some extent large trees as repositories of fungal diversity, which should be considered in conservation planning
The diel niche of brown bears: constraints on adaptive capacity in human-modified landscapes
No full textDiel activity rhythms, representing the behavioral pattern of the sleep-wake cycle, may be adjusted by wildlife in response to changes in environmental conditions. An increase in nocturnality is typically recognized as an adaptive strategy to segregate from humans and mitigate heat stress. Numerous studies have investigated spatial patterns and habitat use of large carnivores in human-modified landscapes, but little research has examined their activity rhythms. We compiled Global Positioning System data (2004-2022) for 139 brown bears Ursus arctos from six populations across Europe, representing a human-modified landscape, and the Greater Yellowstone Ecosystem, U.S.A., representing a landscape with limited human impact, which we used to calculate hourly movement rates as an activity proxy. Using a Bayesian approach to model the temporal autocorrelation of activity data, we tested if the extent of nocturnality in brown bears is modulated by intensity of human encroachment, accounting for primary productivity and maximum ambient temperature. All bear populations exhibited a predominantly bimodal, crepuscular pattern of activity, although Yellowstone bears were proportionally more crepuscular and diurnal. Whereas the effect of primary productivity was variable, all European populations became more nocturnal in response to higher human encroachment and reduced diurnal and crepuscular activity at higher summer temperatures, decreasing overall diel activity levels. Yellowstone bears displayed the greatest shift towards nocturnality among all populations in response to increasing human encroachment, and increased nocturnal activity to compensate for lower diurnal and crepuscular activity at higher summer temperatures. Our research indicates that European bears in human-modified landscapes may be reaching a limit in the behavioral plasticity they can manifest in their activity patterns, being already constrained into increased nocturnality. Our findings enhance the understanding of brown bear adaptive capacity to accommodate future changes, such as urbanization and increasing temperatures, to the ecosystems they inhabit