Annual plant neighbourhoods

As a team, we are discussing the fine-scale grain of sampling for estimating annual-annual plant interactions in deserts. We are particularly interested in the Mojave Desert to examine pollinator-herbivore interactions with annuals that are mediated by the other immediately adjacent congeneric species. Here is a brief compilation of key papers examining this challenge.

scale matters, a plant’s eye view

Publications describing the fine-scale annual plant neighbourhood concept

Mack, R. N. and Harper, J. L. 1977. Interference in dune annuals: spatial pattern and neighbourhood effects. – Journal of Ecology 65: 345-363.

Holzapfel, C. and Mahall, B. E. 1999. Bidirectional facilitation and interference between shrubs and annuals in the Mojave desert. – Ecology 80: 1747-1761.

Schiffers, K. and Tielbörger, K. 2006. Ontogenetic Shifts in Interactions among Annual Plants. – Journal of Ecology 94: 336-341.

Lortie, C. J. and Turkington, R. 2008. Species-specific positive effects in an annual plant community. – Oikos 117: 1511-1521.

Emery, N. C., Stanton, M. L. and Rice, K. J. 2009. Factors driving distribution limits in an annual plant community. – New Phytologist 181: 734-747.

Luzuriaga, A. L., Sánchez, A. M., Maestre, F. T. and Escudero, A. 2012. Assemblage of a Semi-Arid Annual Plant Community: Abiotic and Biotic Filters Act Hierarchically. – PLOS ONE 7: e41270.

Underwood, N., Inouye, B. D. and Hambäck, P. A. 2014. A Conceptual Framework for Associational Effects: When Do Neighbors Matter and How Would We Know? – The Quarterly Review of Biology 89: 1-19.

Underwood, N., Hambäck, P. A. and Inouye, B. D. 2020. Pollinators, Herbivores, and Plant Neighborhood Effects. – The Quarterly Review of Biology 95: 37-57.

Personal vote

I am a fan of the 15cm scale for fine-scale but often sample with a 15cm ring nested within a second 30cm metal ring. I construct using wire.

Jacob’s schedule — let’s be friends!

Here’s my [approximate] travel schedule for this summer. It’d be great to connect any time we happen to be in the same place at the same time!

  • April 6-20: Veg sampling and experimental site selection in Cali/Nevada
  • May 20(ish): B. rubens seed collection in Cali/Nevada
  • May 25-June 2: E. lobata sampling in Toronto
  • August 2-7: ESA in Salt Lake
  • Sept 16-21: E. lobata sampling in Toronto
  • Sept. 25-Oct. 11: Install facilitation x granivory experiment in Cali/Nevada.

Biotic interactions in the native and non-native ranges of invasive Bromus rubens

One of the most powerful approaches for understanding biological invasions by non-native species is to examine ecological patterns and processes in both the native and non-native ranges of invasive species. Here’s a great article on the subject:

https://doi.org/10.1111/j.0022-0477.2004.00953.x

The number of articles published on biological invasions has increased exponentially over the last 20 years, but biogeographically explicit studies replicated in the native and non-native ranges of invasive species are still VERY rare. This hampers our mechanistic understanding of the invasion process and therefore our ability to explain, predict, and manage biological invasions.

Bromus rubens (i.e., red brome) invasion in the Mojave Desert provides a great opportunity to address this knowledge gap. We are planning to examine the individual and joint effects of shrub facilitation and post-dispersal seed predation on the abundance of B. rubens in its native (Israel) and non-native (California and Nevada) ranges. This experiment is broadly interesting because it allows us to test the relative importance of the effects of two fundamental biotic interactions on two continents. Here’s a cartoon of our experimental design:

Solid circles represent functional exclosures that effectively exclude seed predators; dashed circles represent non-functional exclosures that admit seed predators. Note the control treatment that monitors recruitment from seed banks. This is a full-factorial design that crosses shrub facilitation (open vs. shrub microsites) with seed predation (functional vs. non-functional exclosures). Pretty cool.

We will replicate this setup at 5 shrub-open pairs per site at 6 sites across the Mojave (GPS coordinates are preliminary):

Sitelatlong
Veg36.44603-114.96
Mes36.75986-114.07
Bak35.40529-115.797
HOM34.71012-115.689
Need34.49663-114.733
Palm34.16122-115.714

We will replicate the experiment at 5 sites in the Negev Desert of Israel with the help of Dr. Merav Seifan of the Ben Gurion University of the Negev. She rocks! Site locations and GPS coordinates in Israel are forthcoming.

The biogeographic contrast of the effects of seed predation can be considered a test of the enemy release hypothesis, which has only been examined once in the context of seed predation:

https://doi.org/10.1002/ece3.5314

However, the biogeographic contrast of the effects of shrub facilitation is COMPLETELY NOVEL…I think 🙂

We begin work this spring! We’ll keep you posted.

Three new active dryland ecological restoration sites up online this winter.

Lancaster site
34.703780, -118.309870

Yucca Grove
35.405209, -115.797010

Panoche Hills Ecological Reserve
36.6446735, -120.8719203

Methods

Active restoration of native vegetation and seeds.
Invertebrate sampling.
Camera trapping.
Contrast with regional patterns of diversity.

Team kicking off extreme ecology research in Tierra del Fuego

In collaboration with Professor Katie O’Meara, an architect, Professor Zaitchik, an Earth Scientist, and researcher Claire Moriarty, we are examining the use of drones to map keystone species in extreme environments such as cushion plants in Patagonia or shrubs in deserts. This is just a pilot experiment (haha, get it), and we need a graduate student for 2020 to dig in and ground-truth the metrics we will derive from imagery. The focus will be structure and architecture in natural systems.

Bromus ecotypic contrast experiment up and running in Israel for winter growing season 2020

York Science Fellow Dr. Jacob Lucero and international collaborator Dr Merav Seifan are launching into 2020 with an ambitious experiment in Israel and California. The purpose is to explore the relative importance of provenance of a highly invasive species of bromus in the deserts of California by comparing performance and key interactions in its home range, Israel, and in its introduced range, California. This is a new direction from previous work published in NeoBiota entitled ‘The dark side of facilitation: native shrubs facilitate exotic annuals more strongly than native annuals’ that demonstrated a very significant effect of bromus on local plant community dynamics.

Setup in Israel was a positive adventure!

Greenhouse Experiment Setup

Red Brome (invasive species) and Phacelia tanacetifolia (native annual)

Fake plastic Red Brome and 3D-printed Red Brome (mimics seedling stage)

Labelling…

Setting up!

Testing different spatial patterns (clumped and dispersed)

All pots seeded and labelled!

Measuring light intensity

steps to update a manuscript that was hung up in peer review forever then rejected (or just neglected for a long time)

Sometimes, peer review (and procrastination) help. Other times, the delays generate more net work. I was discussing this workflow with a colleague regarding a paper that was submitted two-years ago, rejected, then we both ran out of steam. This was the gold-standard workflow we proposed (versus reformat and submit to another journal immediately).

Workflow

  1. Hit web of science and check for new papers on topic.
  2. Download the pdfs.
  3. Read them.
  4. Think about what to cite or add.
  5. Add citations and rebuild biblio. 
  6. Update writing to mention new citations especially if they are really relevant (intro and discussion).
  7. Take whatever pearls of wisdom you can from rejection in first place and revise ideas, plots, or stats.
  8. Format for new journal.
  9. Check requirements for that journal.
  10. Search the table of contents for the journal and check your lit cited to ensure you cite a few papers from that journal – if not, assess whether that the right journal for this contribution.
  11. Download pdfs from new journal, read, cite, and interpret.
  12. Then, look up referees and emails.
  13. Write cover letter.
  14. Set up account for that new and different annoying journal system – register and wait.
  15. Fight with system to submit and complete all the little boxes/fields.

Better knitting to pdf

Lab meeting sketches

No markers go a long way to better meetings!

RDM thoughts
the seed mass-number challenge