| 1. |
- Aguirre Salcedo, Citlali, 1992-, et al.
(författare)
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Restoration implications of the germination ecology of six dry-forest woody Fabaceae species in Mexico
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Germination kickstarts plant recruitment. Hence, acknowledging this process is a prerequisite for restoration of ecosystems. In dry forests, where opportunities for plant establishment occur in a narrow window of opportunity, seeds must respond to cues to germinate when conditions for growth are suitable. Understanding the strategies and adaptations of seeds to the seasonal dry-forest ecosystems is needed to guide restoration and management actions in the face of climate change. We investigated the effects of scarification, temperature and light in germination percentage, germination time and synchrony of six woody Fabaceae species. The species have ecological potential for restoration and are of cultural and economic importance for the local people in the Tehuacán-Cuicatlán Valley, Mexico. We carried out a multifactorial germination experiment with five temperatures, two light regimes and two scarification conditions for Mimosa luisana, M. polyantha, M. adenantheroides, M. lactiflua, Acaciella angustissima and Vachellia constricta. Responses differed among the species, but they all germinated in a wide range of temperatures (10°C to 40°C). Mechanical scarification highly increased the germination percentage of all species. Higher temperature increased and speeded up germination in dark conditions for most of the species. We found more heterogeneous responses in germination synchrony among species. Despite that the studied species had high germination percentages in warm temperatures, their recruitment in nature might be negatively affected by warmer and drier conditions, and by the loss of shade and seed dispersers due to deforestation and changes in land use. It is crucial to study not just germination percentage and time but also other aspects of the germination process such as the germination synchrony, since it might reveal useful information for management actions.
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| 2. |
- Aguirre Salcedo, Citlali, 1992-, et al.
(författare)
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Seed trait differentiation and plant growth among Mimosa luisana populations
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The arid and semi-arid vegetation zones of the world often harbour high species diversity and significant endemism. They also face elevated levels of environmental pressures due to high human settlement densities and weak institutional systems. This necessitates adequate conservation and ecological restoration efforts, which in turn demand physiological and ecological knowledge of the species involved. Seed traits can be important for plant establishment success and growth, especially at early life stages, when seedlings also are most sensitive. We studied the role of seed traits for early establishment of the woody Fabaceae species Mimosa luisana, a candidate species for use in ecological restoration within the Tehuacán-Cuicatlán Valley (TCV), Mexico. We assessed the relationship between seed traits and biomass production, biomass allocation and relative growth rate (RGR) up to 200 days after germination, in a common garden experiment using three populations that represented the lower, central and upper limit of M. luisana geographical distribution. M. luisana seeds were 1.9-3.9 mm long, 1.7-3.3 mm wide, 1.2-2.9 mm thick, and weighed from 3 to 19 mg. We found the seeds from the lower limit to be lighter, thinner and less spherical than the central and upper populations. Across all populations, 41% of the total biomass consisted of leaves, followed by shoots (33%) and roots (27%). The biomass production and allocation showed no significant difference among populations during the initial harvests; however, discernible differences emerged over time. Seed weight initially had a significant effect on biomass production, but this effect was lost with time. Seed weight alone explained only 0.82% of the total variance of biomass production, while harvest age explained 40.05%, and seed provenance 3.08%. The correlation between seed weight and RGR was slightly negative but not significant. These results have implications for efforts to ecologically restore dry forests in the region as well as how to implement climate change adaptation and conservation translocation actions, as these might imply sowing and establishing M. luisana at new sites. Given the small variance in biomass accumulation explained by seed traits and provenance, efforts to protect M. luisana during germination and establishment are likely to be more important for management success than the seed source used.
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| 3. |
- Aguirre Salcedo, Citlali, 1992-
(författare)
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Steering ecological restoration efforts through the storm of climate change : the case of tropical dry forest shrub species
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Climate change compels a reconsideration of prevailing ecological restoration paradigms and methodologies. The main goal of this thesis thesis was to explore strategies to adapt the practices of ecological restoration to climate change. We studied the potential response of six Fabaceae shrub species from tropical dry forests, previously identified as potential candidates for ecological restoration, to anticipated climate change. We found Fabaceae woody shrub species germinated in a wide range of temperatures, light and darkness, and require mechanical scarification to break their physical dormancy. We combined modelling, laboratory, field and nursery experiments to unravel the potential response of Mimosa luisana to climate change. We found trait differentiation among the lower, central and upper population of the species current distribution range within the Tehuacán-Cuicatlán Valley (TCV), Mexico, but not local adaptation. The climatically suitable area of M. luisana is projected to expand, and experimentally, this species could tolerate a wide range of conditions in terms of temperature and soil moisture. Therefore, not need for. assisted migration was found. Seed size differed among M.luisana populations, and showed a significant effect in early biomass production, but not in relative growth rate. This work has directly implications for restoration practices. First, because it addressed some of the challenges posed by climate change by highlighting methodologies that could be replicated for other species and ecosystems. Second, because it provides concrete guidelines for restoring ecological processes in tropical dry lands as the Tehuacán-Cuicatlán Valley, Mexico, that could be implemented by academics and local communities.
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| 4. |
- Aguirre Salcedo, Citlali, 1992-, et al.
(författare)
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To move or not to move: assessing the viability of translocating Mimosa luisana for climate adaptation in the Tehuacán-Cuicatlán Valley, Mexico
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Climate change is threatening range-restricted species world-wide, but assessments of vulnerability is lacking in many areas, especially in tropical mountain regions. We assessed the vulnerability of the tropical dry forest species Mimosa luisana, an important nurse plant facilitating the establishment of other species, and provider of ecosystem services to local communities. We projected changes in the geographic distribution and extent of the climatic envelope of M. luisana for the periods 2021-2040, 2041-2060, 2061-2080, using the Maximun Entropy species distribution model (MaxEnt). We also tested the response of local provenances of M. luisana to different climate change scenarios by transplanting them to new elevations. We found that new areas at higher elevation will become climatically suitable for M. luisana in the future, without losing its current geographic range, so that its geographic range may expand by between 50% and 313%. Transplantation showed that M. luisana can grow and survive in a wide range of conditions. Moreover, M. luisana was able to survive when translocated 700 m upwards, to areas above its current elevational limit. We conclude that M. luisana is not in need of assisted migration to escape climate-related extinction, but translocation to areas that become climatically suitable may be beneficial to its conservation. The species may be used in ecological restoration projects in a wide range of conditions, including beyond its present range, increasing the likelihood of success in present and future ecological restoration actions. However, we acknowledge the need for assessing the climate-change effects on reproduction and the dispersal capacity of the species.
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| 5. |
- Aguirre Salcedo, Citlali, 1992-, et al.
(författare)
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Trait differentiation and local adaptation of a local endemic shrub along a tropical dry forest gradient : a reciprocal transplant experiment
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Rapid climate change imperils a multitude of species, demanding either swift adaptation or a strategic migration to new areas to safeguard their existence. Species confined to spatially limited habitats face heightened vulnerability as ecological conditions may undergo dramatic shifts across their range. In this study, we delve into the processes shaping the geographic distribution of Mimosa luisana, a species endemic to the Tehuacán-Cuicatlán Valley in Mexico, having high potential for use in ecological restoration. We aimed to forecast the response of M. luisana to climate change and to formulate strategic management guidelines in the face of global change. We conducted a reciprocal translocation and a common garden experiment with three provenances of M. luisana. We used populations originating from the lower, central and upper range-limit of the altitudinal and latitudinal distribution of the species. We found significant differences in the relative growth rate, leaf biomass change and specific leaf area among the three provenances during their early establishment, but found little evidence of local adaptation among the studied populations. Instead, all provenances did best at the central part of the species range. We suggest that cold temperatures might be delimiting the upper limit of M. luisana within the Tehuacán-Cuicatlán Valley, whereas tolerance to drought may set lower limits. M. luisana might respond to climate change not by upward shifts of each locally adapted population distributed along the elevational gradient, but by conditions improving at the high-elevation edge in response to warming. A management implication from our results is that ensuring genetic diversity of the seed batches may be more important than only using local seed sources of M. luisana in ecological restoration actions.
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| 6. |
- Alimpić, Filip, et al.
(författare)
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The status and role of genetic diversity of trees for the conservation and management of riparian ecosystems : A European experts' perspective
- 2022
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Ingår i: Journal of Applied Ecology. - : John Wiley & Sons. - 0021-8901 .- 1365-2664. ; 59:10, s. 2476-2485
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Tidskriftsartikel (refereegranskat)abstract
- Riparian vegetation supports high biodiversity providing many services and is, therefore, an important landscape element. Riparian ecosystems are subject to numerous pressures leading to population decline and genetic erosion of riparian plants. This may have cascading effects at various ecosystem levels, including decreasing ecosystem services, so identifying the current status of genetic diversity of riparian tree species is vital to improve the effectiveness of restoration efforts.We aimed to elicit expert views on the status and importance of genetic diversity of tree species, and conservation needs across European riparian ecosystems. Sharing of such information among researchers, managers and policymakers has the potential to enhance ecological restoration and management of riparian ecosystems.We identified experts in riparian genetic resources conservation and management across Europe. These included stakeholders with different perspectives, ranging from researchers to practitioners. We designed a set of questionnaires where our identified experts were asked to answer questions related to the status and conservation of genetic diversity of riparian tree species in their respective countries. Specifically, we asked about societal awareness, legislative tools, good practices and conservation or restoration projects accounting for intraspecific genetic diversity and differentiation of tree species in riparian ecosystems. Questionnaire responses were analysed and discussed in light of the scientific literature to define needs and priorities related to the management and conservation of genetic diversity of riparian tree species.The experts recognized that a combination of in situ and ex situ measures and/or integrative conservation of riparian ecosystems is the most appropriate option for conserving the genetic diversity of riparian tree species. Simultaneous application of conservation measures at the level of priority species, identified by experts, and protection of riparian areas are required.Synthesis and applications. This study revealed the importance of recognizing the ecological processes that shape the genetic diversity of riparian tree species in hydrographic networks (dendritic spatial configuration, specific patterns of gene flow among riparian populations, fragmentation of river by dams) but also the need to overcome socio-economic barriers, such as lack of policy priority, deficiency in funding and weak legislation framework.
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| 7. |
- Bejarano, Maria D., et al.
(författare)
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Hydropeaking affects germination and establishment of riverbank vegetation
- 2020
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Ingår i: Ecological Applications. - : John Wiley & Sons. - 1051-0761 .- 1939-5582. ; 30:4
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Tidskriftsartikel (refereegranskat)abstract
- Hydropeaking, defined as frequent and rapid variation in flow in regulated rivers with hydropower plants over a short period of time, usually sub-daily to weekly, alters hydraulic parameters such as water levels or flow velocity and exerts strong impacts on fluvial ecosystems. We evaluated the effects of hydropeaking on riverbank vegetation, specifically assessing the germination and establishment of seedlings and cuttings of plant species representing a variation in traits. We used seeds and seedlings and cuttings varying in size as phytometers, and transplanted them to riverbanks both above and below dams used for hydropower production in northern Sweden, selected to represent a gradient in hydropeaking intensity, and along a free-flowing reach. We also analyzed sub-daily water-level variables modified by hydropeaking to identify variables key in explaining the observed vegetation patterns. We found that plant responses to hydropeaking varied with species, with flood-intolerant species being the most strongly affected, as early as the germination stage. In contrast, seeds of flood-tolerant species managed to germinate and survive the early establishment phase, although strong erosive processes triggered by hydropeaking eventually caused most of them to fail. The fate of flood-intolerant species identifies germination as the most critical life-history stage. The depth and frequency of the inundation were the leading variables explaining plant responses, while the duration of shallow inundation explained little of the variation. The rise and fall rates of water levels were key in explaining variation in germination success. Based on the results, we propose restoration measures to enhance establishment of riparian plant communities while minimizing the impact on hydropower electricity production. Given the strong decrease in the germination of species intolerant to prolonged flooding with hydropeaking, planting of seedlings, preferably of large sizes, together with restrictions in the operation of the power plant during the establishment phase to enhance survival would be the best restoration option. Given the high probability of plant uprooting with hydropeaking, bank protection measures have the potential to increase riparian plant survival of all species, including flooding-tolerant species.
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| 8. |
- Catford, Jane A., et al.
(författare)
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Reducing redundancy in invasion ecology by integrating hypotheses into a single theoretical framework
- 2009
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Ingår i: Diversity & distributions. - : Wiley. - 1366-9516 .- 1472-4642. ; 15:1, s. 22-40
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Invasion ecology includes many hypotheses. Empirical evidence suggests that most of these can explain the success of some invaders to some degree in some circumstances. If they all are correct, what does this tell us about invasion? We illustrate the major themes in invasion ecology, and provide an overarching framework that helps organize research and foster links among subfields of invasion ecology and ecology more generally.Location: Global.Methods: We review and synthesize 29 leading hypotheses in plant invasion ecology. Structured around propagule pressure (P), abiotic characteristics (A) and biotic characteristics (B), with the additional influence of humans (H) on P, A and B (hereon PAB), we show how these hypotheses fit into one paradigm. P is based on the size and frequency of introductions, A incorporates ecosystem invasibility based on physical conditions, and B includes the characteristics of invading species (invasiveness), the recipient community and their interactions. Having justified the PAB framework, we propose a way in which invasion research could progress.Results: By highlighting the common ground among hypotheses, we show that invasion ecology is encumbered by theoretical redundancy that can be removed through integration. Using both holistic and incremental approaches, we show how the PAB framework can guide research and quantify the relative importance of different invasion mechanisms.Main conclusions: If the prime aim is to identify the main cause of invasion success, we contend that a top-down approach that focuses on PAB maximizes research efficiency. This approach identifies the most influential factors first, and subsequently narrows the number of potential causal mechanisms. By viewing invasion as a multifaceted process that can be partitioned into major drivers and broken down into a series of sequential steps, invasion theory can be rigorously tested, understanding improved and effective weed management techniques identified.
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| 9. |
- Dawson, Michael N., et al.
(författare)
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A second horizon scan of biogeography: Golden ages, Midas touches, and the Red Queen
- 2016
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Ingår i: Frontiers of Biogeography. - : University of California. - 1948-6596. ; 8:4
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Tidskriftsartikel (refereegranskat)abstract
- Are we entering a new 'Golden Age' of biogeography, with continued development of infrastructure and ideas? We highlight recent developments, and the challenges and opportunities they bring, in light of the snapshot provided by the 7th biennial meeting of the International Biogeography Society (IBS 2015). We summarize themes in and across 15 symposia using narrative analysis and word clouds, which we complement with recent publication trends and 'research fronts'. We find that biogeography is still strongly defined by core sub-disciplines that reflect its origins in botanical, zoological (particularly bird and mammal), and geographic (e.g., island, montane) studies of the 1800s. That core is being enriched by large datasets (e.g. of environmental variables, 'omics', species' occurrences, traits) and new techniques (e.g., advances in genetics, remote sensing, modeling) that promote studies with increasing detail and at increasing scales; disciplinary breadth is being diversified (e.g., by developments in paleobiogeography and microbiology) and integrated through the transfer of approaches and sharing of theory (e.g., spatial modeling and phylogenetics in evolutionary-ecological contexts). Yet some subdisciplines remain on the fringe (e.g., marine biogeography, deep-time paleobiogeography), new horizons and new theory may be overshadowed by popular techniques (e.g., species distribution modelling), and hypotheses, data, and analyses may each be wanting. Trends in publication suggest a shift away from traditional biogeography journals to multidisciplinary or open access journals. Thus, there are currently many opportunities and challenges as biogeography increasingly addresses human impacts on, and stewardship of, the planet (e.g., Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services). As in the past, biogeographers doubtless will continue to be engaged by new data and methods in exploring the nexus between biology and geography for decades into the future. But golden ages come and go, and they need not touch every domain in a discipline nor affect subdisciplines at the same time; moreover, what appears to be a Golden Age may sometimes have an undesirable 'Midas touch'. Contexts within and outwith biogeography-e.g., methods, knowledge, climate, biodiversity, politics-are continually changing, and at times it can be challenging to establish or maintain relevance. In so many races with the Red Queen, we suggest that biogeography will enjoy greatest success if we also increasingly engage with the epistemology of our discipline.
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| 10. |
- Dawson, Michael N., et al.
(författare)
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An horizon scan of biogeography
- 2013
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Ingår i: Frontiers of Biogeography. - : International Biogeography Society. - 1948-6596. ; 5:2, s. 130-157
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Tidskriftsartikel (refereegranskat)abstract
- The opportunity to reflect broadly on the accomplishments, prospects, and reach of a field may present itself relatively infrequently. Each biennial meeting of the International Biogeography Society showcases ideas solicited and developed largely during the preceding year, by individuals or teams from across the breadth of the discipline. Here, we highlight challenges, developments, and opportunities in biogeography that were summarized at or emerge from that biennial synthesis. We note the realized and potential impact of rapid data accumulation in several fields, a Renaissance for inter-disciplinary research, the importance of recognizing the evolution-ecology continuum across spatial and temporal scales and at different taxonomic, phylogenetic and functional levels, and re-exploration of classical assumptions and hypotheses using new tools. However, advances are taxonomically and geographically biased, key theoretical frameworks await development of tools for handling, or strategies for simplifying, the biological complexity seen in empirical systems. Current threats to biodiversity require unprecedented integration of knowledge and development of predictive capacity that may enable biogeography to unite its descriptive and hypothetico-deductive arms and establish a greater role within and outside academia.
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