York University Conference talk for Northern Studies Training Program. Presentation examines the cost of facilitation for cushion plants in the alpine.
Sequestering soil carbon in the low input farming systems of the semi-arid tr...ExternalEvents
This presentation was presented during the 2 Parallel session on Theme 3.3, Managing SOC in: Dryland soils, of the Global Symposium on Soil Organic Carbon that took place in Rome 21-23 March 2017. The presentation was made by Mr. Anthony M. Whitbread, from International Crops Research Institute for the Semi-Arid Tropics – India, in FAO Hq, Rome
GGEBiplot analysis of genotype × environment interaction in Agropyron interme...Innspub Net
In order to identify genotypes of Agropyron intermedium with high forage yield and stability an experiment was carried out in the Research station of Kermanshah Iran.The 11 accessions were sown in a randomized complete block design with three replications under rainfed and irrigated conditions during 2013-21-014 cropping deasons. Combined analysis of variance indicated high significant differences for location, genotype and G × E interaction (GEI) at 1% level of probability. Mean comparisons over environments introduced G4, G3 and G5 with maximum forage yield over rainfed and irrigated conditions. Minimum forage yield was attributed to genotype G1. GGEbiplot analysis exhibited that the first two principal components (PCA) resulted from GEI and genotype effect justified 99.37% of total variance in the data set. The four environments under investigation fell into two apparent groups: irrigated and rainfed. The presence of close associations among irrigated (E1 and E3) and rainfed (E2 and E4) conditions suggests that the same information about the genotypes could be obtained from fewer test environments, and hence the potential to reduce testing cost.The which-won-where pattern of GGEbiplot introduced genotypes G3 and G4 as stable with high forage yield for rainfed condition, while G5 was stable with high yield for irrigated condition. According to the comparison of the genotypes with the Ideal genotype accessions G4, G3 and G9 were more favorable than all the other genotypes. Get more articles at: http://www.innspub.net/volume-6-number-4-april-2015-jbes/
Sequestering soil carbon in the low input farming systems of the semi-arid tr...ExternalEvents
This presentation was presented during the 2 Parallel session on Theme 3.3, Managing SOC in: Dryland soils, of the Global Symposium on Soil Organic Carbon that took place in Rome 21-23 March 2017. The presentation was made by Mr. Anthony M. Whitbread, from International Crops Research Institute for the Semi-Arid Tropics – India, in FAO Hq, Rome
GGEBiplot analysis of genotype × environment interaction in Agropyron interme...Innspub Net
In order to identify genotypes of Agropyron intermedium with high forage yield and stability an experiment was carried out in the Research station of Kermanshah Iran.The 11 accessions were sown in a randomized complete block design with three replications under rainfed and irrigated conditions during 2013-21-014 cropping deasons. Combined analysis of variance indicated high significant differences for location, genotype and G × E interaction (GEI) at 1% level of probability. Mean comparisons over environments introduced G4, G3 and G5 with maximum forage yield over rainfed and irrigated conditions. Minimum forage yield was attributed to genotype G1. GGEbiplot analysis exhibited that the first two principal components (PCA) resulted from GEI and genotype effect justified 99.37% of total variance in the data set. The four environments under investigation fell into two apparent groups: irrigated and rainfed. The presence of close associations among irrigated (E1 and E3) and rainfed (E2 and E4) conditions suggests that the same information about the genotypes could be obtained from fewer test environments, and hence the potential to reduce testing cost.The which-won-where pattern of GGEbiplot introduced genotypes G3 and G4 as stable with high forage yield for rainfed condition, while G5 was stable with high yield for irrigated condition. According to the comparison of the genotypes with the Ideal genotype accessions G4, G3 and G9 were more favorable than all the other genotypes. Get more articles at: http://www.innspub.net/volume-6-number-4-april-2015-jbes/
Objectives
- Understand and model the new paradigm of soil carbon (C) stabilization at the C-microbe-mineral interface with varying:
-Carbon input chemistry
-Microbial community composition, and
-Soil mineralogy
- Integrate findings across spatial (molecular to landscape) and temporal scales using:
Gradients of soil age (~40 to 250 ka), and climate (~300 to 1200 mm yr-1)
- Incorporate improved mechanistic understanding of C stabilization/destabilization into new reactive transport models
This is the presentation given during Diego Sotomayor's PhD defence at the Department of Geography at York University.
This is the abstract of the dissertation:
In arid environments, dominant woody plants such as shrubs or trees, usually facilitate a high density of species in their understories. This phenomemon is composed by a series of direct and indirect effects from the dominant plant to the understory species, and among understory species. The aim of this project was to determine these direct and indirect consequences of dominant plant-plant facilitation in a collection of field sites along the coastal Atacama Desert. The following objectives and hypotheses were examined in this project: (1) to summarize and contextualize the breadth of research on indirect interactions in terrestrial plant communities; (2) that the positive effects of dominant plants on understory communities are spatiotemporally scale dependent, from micro- to broad-scale spatial effects, and from within-seasonal to among-year temporal effects; (3) that dominant plants via their different traits determine the outcome of plant-plant interactions; (4) that dominant plants determine the outcome of interactions amongst understory species and that their responses are species-specific; and (5) that facilitation by dominant plants generates sufficiently different micro-environmental conditions that lead to consistent differences in seeds traits of understory plants. Overall, we found that multiple factors determine the outcome of plant-plant interactions along the field sites studied in this project. These factors impact both the direct and indirect effects of dominant woody plants on their understory communities and include species-specific traits of both the dominant and understory species, and the spatial and temporal environmental gradients that manifest their effects at different scales. Dominant plants usually facilitate increased species richness and density of plants in their understory, that in turn mediates effects amongst these species. However, these direct effects seem to have a limit given that at extremely stressful environmental conditions they tend to change to neutral and even competitive effects of canopies on their understories. This provides evidence that positive effects of dominant plants collapse under extreme spatiotemporal stress. Although we did not find evidence of evolutionary effects of top-down facilitation, the methodology proposed here represents a contribution to test the conditions under which these results hold. Overall, this project illustrates the importance of understanding the multiple drivers that determine the outcome of biotic interactions.
Objectives
Characterize the soil microbial community across different management practices and measure the corresponding greenhouse gas fluxes.
Determine the adaptation and acclimation of the soil microbial community climate change.
Improve a soil greenhouse gas emission model to predict greenhouse gas emissions under global change scenarios.
- Explore how crop and forest management influences decadal scale climate predictions
- Improve the representation of managed ecosystems in Earth system models
- Specific focus on institutional strengths: soil carbon dynamics, pine plantation forestry, plant physiology under warming temperatures, forest nitrogen cycling
- Evaluate and reduce uncertainty associated with ecological processes in climate predictions
This is to share the short power point on my MSc research - Thesis defense at ITC, NL. It was a 10 minutes presentation, followed by questions from the assessment board. And I got a green card, was a successful defense :)
Stability parameters for comparing varieties (eberhart and russell 1966)Dhanuja Kumar
Phenotype is a result of genotype, environment and GE interaction. GENOTYPE- environment interactions are of major
importance to the plant breeder in developing
improved varieties. The performance of a single variety is not the same in all the environments. To identify a genotype whose performance is stable across environments various models were proposed. One such model was proposed by EBERHART and RUSSELL in 1966. Even after decades, this model is still preferred over others and used till date for stability analysis.
Devising a citizen science monitoring programme for tree regeneration the upl...Muki Haklay
Presentation by Chris Andrews from a participatory virtual workshop June 2020 on citizen science in the Cairngorms national park. Aims of presentation: To provide a background information as to what's going on ecologically in the uplands; To explore why some upland habitats might be changing; Example of what could be done through a case study at the ECN Cairngorm long-term monitoring site; Provide a framework in which to think about what variables might be useful to citizen science project on monitoring regeneration.
Objectives
- Understand and model the new paradigm of soil carbon (C) stabilization at the C-microbe-mineral interface with varying:
-Carbon input chemistry
-Microbial community composition, and
-Soil mineralogy
- Integrate findings across spatial (molecular to landscape) and temporal scales using:
Gradients of soil age (~40 to 250 ka), and climate (~300 to 1200 mm yr-1)
- Incorporate improved mechanistic understanding of C stabilization/destabilization into new reactive transport models
This is the presentation given during Diego Sotomayor's PhD defence at the Department of Geography at York University.
This is the abstract of the dissertation:
In arid environments, dominant woody plants such as shrubs or trees, usually facilitate a high density of species in their understories. This phenomemon is composed by a series of direct and indirect effects from the dominant plant to the understory species, and among understory species. The aim of this project was to determine these direct and indirect consequences of dominant plant-plant facilitation in a collection of field sites along the coastal Atacama Desert. The following objectives and hypotheses were examined in this project: (1) to summarize and contextualize the breadth of research on indirect interactions in terrestrial plant communities; (2) that the positive effects of dominant plants on understory communities are spatiotemporally scale dependent, from micro- to broad-scale spatial effects, and from within-seasonal to among-year temporal effects; (3) that dominant plants via their different traits determine the outcome of plant-plant interactions; (4) that dominant plants determine the outcome of interactions amongst understory species and that their responses are species-specific; and (5) that facilitation by dominant plants generates sufficiently different micro-environmental conditions that lead to consistent differences in seeds traits of understory plants. Overall, we found that multiple factors determine the outcome of plant-plant interactions along the field sites studied in this project. These factors impact both the direct and indirect effects of dominant woody plants on their understory communities and include species-specific traits of both the dominant and understory species, and the spatial and temporal environmental gradients that manifest their effects at different scales. Dominant plants usually facilitate increased species richness and density of plants in their understory, that in turn mediates effects amongst these species. However, these direct effects seem to have a limit given that at extremely stressful environmental conditions they tend to change to neutral and even competitive effects of canopies on their understories. This provides evidence that positive effects of dominant plants collapse under extreme spatiotemporal stress. Although we did not find evidence of evolutionary effects of top-down facilitation, the methodology proposed here represents a contribution to test the conditions under which these results hold. Overall, this project illustrates the importance of understanding the multiple drivers that determine the outcome of biotic interactions.
Objectives
Characterize the soil microbial community across different management practices and measure the corresponding greenhouse gas fluxes.
Determine the adaptation and acclimation of the soil microbial community climate change.
Improve a soil greenhouse gas emission model to predict greenhouse gas emissions under global change scenarios.
- Explore how crop and forest management influences decadal scale climate predictions
- Improve the representation of managed ecosystems in Earth system models
- Specific focus on institutional strengths: soil carbon dynamics, pine plantation forestry, plant physiology under warming temperatures, forest nitrogen cycling
- Evaluate and reduce uncertainty associated with ecological processes in climate predictions
This is to share the short power point on my MSc research - Thesis defense at ITC, NL. It was a 10 minutes presentation, followed by questions from the assessment board. And I got a green card, was a successful defense :)
Stability parameters for comparing varieties (eberhart and russell 1966)Dhanuja Kumar
Phenotype is a result of genotype, environment and GE interaction. GENOTYPE- environment interactions are of major
importance to the plant breeder in developing
improved varieties. The performance of a single variety is not the same in all the environments. To identify a genotype whose performance is stable across environments various models were proposed. One such model was proposed by EBERHART and RUSSELL in 1966. Even after decades, this model is still preferred over others and used till date for stability analysis.
Devising a citizen science monitoring programme for tree regeneration the upl...Muki Haklay
Presentation by Chris Andrews from a participatory virtual workshop June 2020 on citizen science in the Cairngorms national park. Aims of presentation: To provide a background information as to what's going on ecologically in the uplands; To explore why some upland habitats might be changing; Example of what could be done through a case study at the ECN Cairngorm long-term monitoring site; Provide a framework in which to think about what variables might be useful to citizen science project on monitoring regeneration.
IARU Global Challenges 2014 Cornell Tracking our declineSarah Cornell
There is growing attention to the global risks - not just local impacts - of present rates of biodiversity loss. It is worth keeping in mind that 'biodiversity loss' actually means the destruction (sometimes irreversible) – by us, people – of living organisms, Earth's 'genetic library', species, ecosystems and habitats. The fact that ecosystems are complex, adaptive, and locally specific means they can't be adequately represented in a single global measure. But without any overarching global perspective on losses, the locally contingent measures are 'untethered' to the real risks of systemic change. Scientists of many kinds are rising to the transdisciplinary challenge of dealing with this complexity in the face of global drivers of change (climate change, development pressures), recognizing that it is a challenge for everyone, not just academia.
Placing Our University Campuses in the Context of their Regional Landscapeshealthycampuses
Lael Parrott, Director of the Okanagan Institute for Biodiversity, Resilience, and Ecosystem Services (BRAES), UBC Okanagan, Kelowna, BC, Canada, presented at the 2015 International Conference on Health Promoting Universities and Colleges.
Conventional approaches to sustainability focus on a harm reduction and damage limitation agenda. The theoretical emergence of regenerative sustainability argues we should place social and ecological imperatives on equal footing, organizing around the idea that human activity can simultaneously improve environmental and human wellbeing. This session was used to explore the potential and practice of this sustainability narrative on higher education campuses. Universities and other higher education settings are unique in their ability to serve as living labs and agents of change for sustainability: they are single owner/occupiers, have a public mandate to create new knowledge and practices for community benefit, and integrate teaching and learning. To that end, UBC is transforming its campuses into living laboratories for sustainability. Faculty, staff and students, along with private, public and NGO sector partners, use the University’s physical setting, as well education and research capabilities, to test, study, teach, apply and share lessons learned, technologies created and policies developed. This talk reported on how academic and operational sustainability activities can support a vision for enhancing environmental and human well-being.
This OECD technical workshop will bring together leading experts on economic, biophysical, and integrated assessment modelling of the interactions between climate change, biodiversity loss, and pollution. The workshop will take stock of ongoing modelling efforts to develop quantitative pathways to study the drivers and impacts of the triple planetary crisis, and the policies to address it. The aim is to identify robust modelling approaches to inform the work for the upcoming OECD Environmental Outlook.
Transformation Pathways - The recovery and restoration of native vegetation.Richard Thackway
Case studies across Australia, including Mulligans Flat and Goorooyarroo, are presented providing insights in plant community resilience, possible system trajectories. Outcomes of each assessment can be used in adaptive management e.g. 1) inform what direct measures of field-based attributes need to be collected to fill gaps in knowledge and 2) to guide potential management interventions to transition a site toward a desired condition state. Each assessment commences with knowledge of local First Nations land management regimes in the early 1800s and is followed by a detailed local scale systematic chronology of land use and land management regimes and a synthesis of relevant ecological data and information on the responses of the plant community over time with observed impacts of on ground regimes and practices. The framework is based on 22 indicators hierarchically organised into ecological function, structural and compositional criteria. Changes in benchmarked values of criteria and indicators over time are used to track the response of a plant community to land management regimes and practices. A transformation index is calculated over time relative to a fully natural reference state. This process enables a competent ecologist to assess status, change and trend of native vegetation (plant community types).
A systematic framework is presented for assessing the outcomes of intentional and unintentional land management practices on the condition components of plant communities. The world over – land management regimes and practices are used to maintain or to transform natural ecosystems by modifying, removing and replacing native vegetation. Equally, management regimes and practices are used to rehabilitate and restore native vegetation (plant community types). Decisions to reconnect fragmented landscapes are informed by such information.
Response measures in the framework are populated using relevant data and information from expert elicitation, environmental histories, interviews with skilled subject specialists, long term ecological monitoring programs and multi-spatial and multi-temporal remote sensing datasets.
Opportunities to Practically Scale-up Perennial FeedstocksAmanda Bilek
Presented by Vance Owens, Director of North Central Sun Grant Center, South Dakota State University on December 8, 2014 at Minnesota Bioenergy Feedstock Development meeting and forum.
Nuts & Bolts: Genetically Appropriate Choices for Plant Materials to Maintain...nycparksnmd
Dr. Arlee Montavalo, University of California, Riverside
Symposium:
What is Local? Genetics & Plant Selection in the Urban Context. (Tuesday, May 23, 2006, American Museum of Natural History)
HLEG thematic workshop on measuring economic, social and environmental resili...StatsCommunications
HLEG thematic workshop on Measuring economic, social and environmental resilience, 25-26 November 2015, Rome, Italy, More information at: http://oe.cd/StrategicForum2015
E-Bird and Climate Change distribution and abundance models, Partners in flight tools for wildlife conservation planning, John Alexander, National Conservation Training Center
Shrubs and invasive grass predict lizard occurrence in an arid shrublandAlessandro Filazzola
Filazzola, A., Westphal, M., Powers, M., Liczner, A.R., Johnson, B, & Lortie, C.J.The realized niche of the endangered blunt-nosed leopard lizard (Gambelia sila) is determined by interactions between native shrubs and invasive annual grass. ESA 100th Meeting Baltimore.
The habitat of the endangered Blunt-nosed leopard lizard is determined by an interplay between native shrub cover and invasive grass abundance. A conference presentation at the 2015 CNPS conference in San Jose.
Proposal for nurse-plant effects on mechanistic pathways for different plant ...Alessandro Filazzola
An introductory explanation of nurse-plant mechanisms and how my research will try to document them. Presented at York University as a part of their weekly graduate series seminars.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
6. Hypothesis
The abundance of beneficiary species negatively co-vary
with cushion-plant traits, particularly reproduction,
because of a parasitic consumption of microsite
resources.
18. Results summarized
Cushion fitness is not generally effected by site
characteristics
The surface area of the cushion is correlated with
both cushion fitness and beneficiary cover
Beneficiary cover is the strongest determinant of
cushion fitness
21. Why Fitness?
• Seed set/fitness is associated with competitive
strength and availability of soil resources (Cornelissen et al.
2003)
• Competition in nutrient-poor systems strongly
determines plant fitness (Aerts 1999)
• Reducing a plants fitness is a form of competition
• Easily measurable response
24. Implications
Previous studies have examined functional variability
of plants because of cushions
Cushion
Open
Almeida et al. 2012. Plant Ecology & Diversity
25. Implications
Other studies have examined functional variability of
strictly cushions
He et al. 2013. Plant Species Biology
26. Implications
Findings are similar to that of Schöb et al. 2013
Community Ecology Theory
Plant trait research
Dominants
i.e. cushions
Plant trait research
Subordinates
i.e. beneficiaries
28. Conclusions
Further support for the cost-of-facilitation theory (in
terms of fitness)
Highlight necessity of treating a plant community as a
response surface
31. Appendix
• Removing surface area effects
Beneficiary effects
not attributable to
surface area
Surface Area m2
Beneficiary Cover
Editor's Notes
Facilitation is the way one plant can positively affect another growing within its vicinity. This can happen through a series of mechanisms such as seed trapping, substrate modification, herbivore protection, etc. We often witness these interactions in high stress environments such as deserts, Mediterranean scrubs and in the alpine.
In the alpine, these dominant plants are cushion plants, which as moss-like perennials that have a mat or almost sponge-like characteristics. These cushions are often keystone species in the systems they inhabit that have been studied extensively on the different ways they interact with neighbouring plants and insects. Typically, the cushions soft composition allows plants to grow within their area, providing benefits such as reduce cold stress, increased soil nutrients and shelter from weather.
What has recently become popular in the literature however is that there can be a cost to this facilitation. While the beneficiary growing within the cushion canopy is getting all of these benefits, this can function as a parasitic relationship for the cushion thereby reducing the fitness or productivity.
Previous studies have tried to examine the effect of beneficiary cover on cushion plant traits. This paper by Schob et al took place in the Spanish Sierra Nevada’s and found that plants growing on cushions negative effect the reproductive output of cushions. Schob and authors examined other cushion plants traits such as SLA (specific leaf area) and leaf dry matter but these were found to not be significant. Thus, it appears that the cost of facilitation typically is relation to the cushion’s fitness.
Our study area was in Pink Mountains in Northern British Columbia. It is a characteristically an arctic tunda environment, although it technically is considered Alpine with the peak being approximately 1500 meters high A.S.L. At the peak the diversity of species is considerably high and heavily dominant by perennials.
My study species is silene acaulis a cushion plant that has been examined previously as a facilitator. Silene is characterized by these bright 5-part purple flowers. During flowering, silene is often covered by these flowers as you can see in this picture. You can also see that there are few plants growing on top of our cushion here. These leafy plants are actually a perennial called Dryas that are growing within the cushion area. My goal was to examine how these plants growing on the backs of the cushion change the cushion traits.
To go about this I need to take a tiered approach to measuring these plant traits. Firstly, I need to measure the landscape level characteristics for all the sites I plan to be working in. *This includes slope inclination, slope exposure, soil heterogeneity, %PAR, etc. This is necessary because sites differed significantly at the plateau of pink mountain both in soil and cushion characteristics. The second tier is to measure the variety of cushion traits. I have a particularly interest in the cushion fitness but I also wanted additional measurements such as cushion penetration, surface area, decadence and number of branches. The last tier is the traits of the beneficiary species to see how they co-vary with cushion traits. This last tier is more the work of future analysis because it is a fair bit of work, but for now I used beneficiary abundance as a proxy. Using this tiered approach is surveyed 140 cushions at nine different sites.
Having these three character matricies can be pretty daunting. Having a vector of site characteristics combined with a matrix of cushion traits which then relates to a matrix of beneficiary traits, I need some form of data reduction technique to make this more manageable. Using principle component analysis I can reduce these matrices, but I also needed to make sure that I’m not including unnecessary variables. With a data-set such as this, not everything I measured is potentially relevant.
RDA1 represents surface area. The bottom right quadrat therefore represents plant species that are most commonly associated with high cushion fitness. You can see that practically every plant species is away from fruit height and density. Bistorta viviparia was found on practically every cushion which is why is positively correlates with fruit ht and density.
Looking at beneficiary coverage and flower height or density we notice that there does not seem to be any obvious trends. From my multivariate analyses it doesn’t appear that anything changes with species composition or beneficiary cover except flower height and flower density. However, when I compare these two estimates of fitness against beneficiary coverage, there is no effect. If anything, I kind of notice a slightly positive relationship between beneficiary coverage and flower height. Perhaps there is a multualistic relationship between these cushion plants and the plants that grow on them.
If you remember from both my PCA and RDA, surface area in each was a strong determinant of cushion traits and community composition. When I compare surface area to species richness and coverage by beneficiaries both are significant. This means that larger cushions are not only home to a greater number of species, but also are generally more covered by beneficiaries. Moreover, when we compare surface area to fruit density, there is a similar positive relationship. This means that we may have a spurious correlation between these beneficiaries and cushion fitness. To determine this we need to fit beneficiaries against fruit density but without the confounding influence of cushion surface area.
Once the surface area effects have been removed there is a negative relationship between beneficiary cover and the fruit density of the cushion. If you have questions about how I removed the effect of surface area, I encourage you to ask afterwards, but the short version is I fit a linear model between surface area and beneficiary without a y-intercept and used the residuals of that model as a proxy for baseline beneficiary effects
So why would you expect plants growing on cushions to have a negative consequence.
Competition for resources. Here is another nurse plant that seems almost engulfed by neighbouring grasses. Having all these plants growing on the same patch of soil means that you are in fierce competition for soil moisture, nutrients and potentially sunlight.
This is even more so in the alpine. These high stress environments are very spatially discrete where a cushion may be the only vascular vegetation for meters. With that being the case, there is high competition simply for land availability. It is then expected that these perennials are going to have to struggle with its neighbours. Alpine is spatially discrete
