Plant-Animal Interactions - Science topic

Dear Oscar Gonzalez, you can use sortweb(data, sort.order="dec") function before you using plotweb() function.

e.g.,

data(Safariland)

plotweb(sortweb(Safariland, sort.order="dec"), method="normal") # Decreasing

plotweb(sortweb(Safariland, sort.order="inc"), method="normal") # Increasing

Hai-Dong

Instead of the LV model, you can use the Nicholson-Bailey model which is originally a host-parasite model but that works well for a plant-herbivore system as well. See for example https://math.la.asu.edu/~dieter/papers/herbivore.pdf

Please you need read a recent review of methods by Caravalli et al. 2017. A review of camera trapping for conservation behaviour research. Remote Sensing in Ecology and Conservation. DOI: 10.1002/rse2.48.

Oliwia,

I am trying to research feeding of berries on frangula alnus using camera traps. I used browning strike force elite trail camera. Got some video of robins at 6ft distance from tree crown but I suspect videos of robin were incidental to other trigger events eg wind triggering branch movement. This has had big implications for my research.

Whatever model you purchase it would be worthwhile testing it at feeding stations that attract robins or other similar sized birds at different distances . Same goes for any species of interest eg if its a mammal try testing with permission at a pet farm that may have it.  I am now testing for detection rate using this method post field work. It would have been better if I had done it before hand but circumstances didn't allow. Sometimes you only know about pitfalls after you spend time and money on equipment and effort.

Also you may like to  search for the following useful papers. the first two are particularly useful I think.

 "Identifying Performance Differences Among Trail Cameras Used to Monitor Forest Mammals" and

"Wildlife camera trapping: a review and recommendations for linking surveys to ecological processes"

and

Management and Analysis of Camera Trap Data: Alternative Approaches

and

An Open Standard for Camera Trap Data

and

Random versus Game Trail-Based Camera

Dear Juan,

the question you are raising is very interesting and much more complicated as it is usually believed. If you are speaking about plant-animal interactions, so you mean mainly mutualistic relations that are studied much more poor than eg competition or predation. This biocenotic relation belongs into bi-directional soft interactions of ++ type (profit for both). I'm working now on a Sub-Chapter about influence of such relations on geographical distribution of invertebrates. The problem of using this knowledge in eco-engineering approaches is still limited into the most simple relations (like starfish-corals) only as all aspects even of not complicated relations can have the long distant consequences, like better growing of some seeds after passing the intestine of grazers, and when killing the last have awful negative influence on baobabs in islands of the Indian Ocean.

So, not long time (after acceptance for publication) will be possibility to put this my Chapter connected all questions you are asking into the Internet. But before - if you have interest - contact me over RG mail, and I'll send you some papers that are like closed for open access about relations between organisms, and possibly my schema of biocenotic relations that is ready for publication as well  This is abs. necessary as if wrong classification of interaction - how to regulate?

Andrey

Hi Juan:

    Ups! I believe that there are many answers to your question. Since my point of view, may be the best way to answer is with an example. Let me explain one.

    In Mexico some colleges (mainly Dra. Coro Arizmendi) and I are trying to build hummingbird gardens. These creations could be very appreciated by people living in the cities. It is because a hummingbird garden could be very colorful due to the flower color of the plants used and the iridescent colors of visiting hummingbirds; besides, if the owner of the garden use native plants, it can help to preserve the local plant species and the vegetation at landscape level, because it offer nectar sources to hummingbirds and improve the visitation of hummingbirds and the pollination done by them at landscape level. Only as example, an environmental engineer can help to design and improve the function of such gardens. In a time when the extinction of pollinators species is a worry, such approach can help to preserve (i.e. it is conservation) the ecological functions of the bird-plant interaction (i.e. it is ecology), and may be that it affect the development of such relationship (i.e. it is evolution).

    I hope that my point of view help in some way.

Regards

Raúl

Kindly also have a look at this link wherein (Chapter 9) the importance of Bees are stressed for self-pollinating crop of Mustard:

Best

Syed

You must first define Seed Dispersal Effectiveness in your study because there are many definitions (see above pdfs). It is easy to associate fruit traits with certain frugivores, but I think it is harder to extend this to SDE. But you can measure things like flight distances, gut passage time of seeds, perching time, etc. These factors will differ among frugivores and can be used to calculate SDE. 

Andrew :-)

Thank You Kennedy.

Looks like Sedum mucizonia to me. Since the plants are not grown in full sun, they are slightly different from the normal appearance.

Best Regards

Sascha

Pactli makes an excellent point, that quantity and quality are two different properties that should be assessed differently. 

I would not use ANOVA for assessing quality (rate of germination) because we are dealing with an underlying binary variable (a seed did or did not germinate) which implies a binomial distribution, making a generalized linear model with a binomial distribution and logit link function more appropriate.  Some logistic regression procedures can handle anova-type variables (i.e., categorical variables, also called class variables, or dummy variables - region would be such a variable).  Under some situations the binomial approaches the normal distribution, but you cannot assume that the normal is a good substitute for the binomial without checking.

I would add a possible third variable to quantity and quality, and that is the spatial distribution of dispersed seeds.  These distributions are often exponential (decreasing exponential) out from the mother plant. With bird dispersal, however, more likely the seeds are dispersed in clusters around perching trees, perhaps with an exponential decline in density between perching trees as you get further away from the mother plant.

Norma Fowler

Your concentrations would be below the detection limit, not necessarily a "true" zero. Negative values: I would double check the (dry) weigh of your samples used to calculate the concentrations.

There a lots of different ways to randomly distribute traps (also depending on trap size) for this purpose, which mostly work well. One important point to look at is which ecosystem you are working in. This should help to define trap size.

The plot size does not necessarily have to be the same. However, the number of traps you set in each plot should be equivalent to the surface area, i.e. you should have the same number of traps/surface area in all plots.

Paola - there was a bunch of work done in Lake St. Clair in the 1990s that originated from the zebra mussel invasion of North America.  The ecology of that system changed so radically owing to increased water clarity, changes in nutrient dynamics from pelagic to benthic, continual inputs of combined sewer overflows and agricultural runoff.  Aquatic macrophytes went bananas in that system - Elodea was one of the main ones.  Check out the Great Lakes Science Center library from that time.  A lot of work was done characterizing those ecosystem shifts.  

Good Luck.

Ray

Hi Filippo - obtaining that sort of data would be great and would really add to our understanding of plant-pollinator networks, but is impossible for diverse assemblages of small, fast-moving insects that may be foraging hundreds or even thousands of metres from their nests.  

Jeff 

The King et al. paper significantly underestimates the amount of time and effort needed to assess pollinator effectiveness, it's not a trivial task for even moderately generalised plant species.  Interaction networks of flower visitation provide a first approximation and have similar properties to pollinator visitation networks (see:  Ollerton J., Johnson S. D., Cranmer, L. & Kellie, S. (2003) The pollination ecology of an assemblage of grassland asclepiads in South Africa. Annals of Botany 92: 807-834)

It's important to realise that visitation is an ecological interaction regardless of the outcome for the plant, though understanding the role of the flower visitor is important if we wish to study things like floral evolution.

Understanding the effect of flower visitation on animal fitness is much more complex and I don't know of any studies that have yet attempted it except for brood-site pollination systems such as figs and fig wasps, and yuccas and yucca moths.

Some tool use in wild chimpanzees is seasonal because they follow the patterns of availability of resources. The type and abundance of vegetation affect the selection of materials used for tools. Besides triggering, does seasonality also shape tool use? We tested the tool performance of 2 chimpanzee groups in a large outdoor compound, enriched with hundreds of plants. We conducted the experiments in 4 seasons to test their behavioural adaptation to the environmental changes. Initially the groups showed preference for different tool materials, one group using grass, abundant in summer, the other using twigs. While twigs were constant through the year, the availability of grass fluctuated greatly, affecting the number of insertions and success of the individuals that used it. Therefore, seasonality did not affect the performance of the group that preferred twigs (less abundant but constant) as it affected the performance of the group that preferred grass (plentiful in certain seasons and scarce in others). We recorded several cases of observation, which may have biased the choices of material. Analysis of the episodes and first insertions of some subjects suggests social transmission, which might explain the initial intergroup difference in tool preference.

Thank you for the paper Andre. I like this kind of intensive field-work experimentation...

I found an interesting paper on pure observational data for ambush predation (ant attacking pollinators). [Rodriguez-Girones et al. 2013 Journal of Ecology 101, 1000-1006. -in case the link is not working-]. I believe that observing events like predation, 100% un-manipulated are a jewel, something that triggers some lines of investigation.