November 2009 Archives

I've just uploaded notes on economic approaches to valuation. I'll be posting what I hope will be clearer guidelines for the little experiment tomorrow morning.

Happy Thanksgiving!

I'd like to try a little experiment as part of the exercise we were starting at the end of class today.

Suppose your total net worth is $1000, meaning that's the most you could possibly spend to prevent extinction of the Sumatran rhino.

Now suppose I told you that there were four different conservation scenarios that have different likelihoods of success.

Scenario A: 25% chance of success
Scenario B: 50% chance of success
Scenario C: 75% chance of success
Scenario D: 100% chance of success

Now tell me how much of your $1000 in net worth you'd be willing to invest in each of the three scenarios.

Please let me know your answers by Friday, and I'll do some illustrative calculations with your responses and share them with you a week from Monday.

By Erica Fleishman and Dennis Murphy (from Conservation Biology):

Charismatic groups of animals and plants often are proposed as sentinels of environmental status and trends. Nevertheless, many claims that a certain taxonomic group can provide more-general information on environmental quality are not evaluated critically. To address several of the many definitions of indicator species, we used butterflies to explore in some detail the attributes that affect implementation of indicators generically. There probably are few individual species, or sets of species, that can serve as scientifically valid, cost-effective measures of the status or trend of an environmental phenomenon that is difficult to measure directly. Nevertheless, there are species with distributions, abundances, or demographic characteristics that are responsive to known environmental changes. In this context, single or multiple species can serve as indicators when targets are defined explicitly, ecological relationships between the target and the putative indicators are well understood, and data are sufficient to differentiate between deterministic and stochastic responses. Although these situations exist, they are less common than might be apparent from an extensive and often confounded literature on indicators. Instead, the public appeal of charismatic groups may be driving much of their acclaim as indicators. The same taxon may not be appropriate for marketing a general conservation mission and for drawing strong inference about specific environmental changes. To provide insights into the progress of conservation efforts, it is essential to identify scientific and practical criteria for selection and application of indicators and then to examine whether a given taxonomic group meets those criteria.

Notes are now posted, along with one paper you may want to take a look at. If time allows, I'm going to try an experiment in class tomorrow that will help the whole approach make a little more sense (I hope).

I just noticed a paper in Biological Conservation that's relevant to yesterday's discussion about the Prendergast et al. paper. Here's a bit of the abstract:

This work had two main objectives: (1) to compare priority sites proposed by the Chilean commission for the environment in a politically driven process to the results of alternative systematic conservation planning scenarios; and (2) to compare the efficacy of systematic conservation planning based on different types of conservation targets (forest types and bird species) and minimum area thresholds. To address these issues, we used vegetation cover as well as field data on forest birds in central Chile. Bird species distributions were modeled using a variety of climatic and environmental layers, allowing for the integration of environmental heterogeneity into the planning process. We then ran several conservation planning scenarios considering conservation targets based on vegetation types alone, birds alone, or a combination of vegetation and birds. Collectively these results show that conservation planning results differ significantly when considering birds or vegetation types, and that minimum area requirements for each conservation feature has a great influence on the final results. (emphasis added)

Here's a link to the paper.

(Oh, and I am very, very close to finishing grading. You should start receiving e-mails from me by 10:30am or sooner.)

I've just uploaded notes and some suggested readings on conservation reserve design. I've also posted materials for short project #3. That's the good news, at least if you were waiting for those things.

The bad news is that I'm still working on project #2 grading. I am very, very sorry, but life has been crazy for me the last couple of weeks.¹ I will do my best to have all of the paper returned by late this evening, but there may be a few that aren't returned until some time tomorrow.

I'll have some notes posted on ecological restoration by tomorrow morning, but it may be 9:00 or 9:30 before they're available. Sorry about that. We'll spend much of our time finishing up our discussion of habitat fragmentation anyway.

I have posted links to some papers related to ecological restoration that you may find interesting.

This week's Nature has a news feature on re-wilding. I've only skimmed it, but it looks well worth reading carefully.

I decided to switch the order of the lectures on habitat fragmentation and ecological restoration. We'll start habitat fragmentation tomorrow after we finish our discussion of species invasions (starting with biological control). I suspect we won't finish everything on habitat fragmentation tomorrow, so we'll probably carry over some of the discussion to the lecture on the 9th of November.

The votes have been tabulated.

• 5 in favor of retaining the original schedule: assign on 11/11, due on 11/18
• 10 in favor of delaying: assign on 11/16, due on 11/30
• 3 either way

A couple of people expressed a concern about the lack of non-holiday weekend time. In the interest of accommodating everyone's concerns, I propose the following:

• Assign Project #3 on 11/16
• Regular due date: 11/30
• For those who are concerned about the lack of non-holiday weekend time: due date 12/7, but only if pre-arranged and only if (a) there aren't too many who want the later date &/or (b) those who want the later date don't mind not getting comments back until after they've handed in their final project.

If you think you'd like to take advantage of the late due date, let me know soon.

I've posted notes on invasives from 2007. I expect to have newly revised notes available by late this afternoon or early this evening. They won't be a lot different from what you can find now, but there will be some updates and a few small changes. So if you want to print a copy, I suggest waiting until tonight or tomorrow. If you just want to look ahead for a preview of what we'll cover tomorrow, dive right in.

I've also posted links to several papers that you may find interesting.

By the way, think about your schedule over the next few weeks and think about when you'd like to have Project #3 due. I'd be willing to assign in on 14 November (instead of 9 November) and set the due date as 30 November, the Monday after Thanksgiving (instead of 21 November). That would give you two weeks (including Thanksgiving break) to work on it. But there's a very good chance I wouldn't be able to get graded papers back to you until Wednesday, 11 December -- just 2 days before your final project is due. Think about it, and we'll talk about it on Monday. I'll bring along ballots so you can vote for one alternative or the other privately.