Rainfall: addendum

In the previous post I made what I thought was a more definitive analysis of the rainfall trends over time. But I think historically and rather linearly it appears, as the charts in that post only looked at rainfall year after year, or as rolling averages.

What if, instead, we look at the distribution of high and low rainfall years? I split the data into 1880-1962 and 1960-2018* and also post-2005. Here’s a graph.

Distribution comparison

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Give us a break, autumn

28/4/2019: See this addendum for an afterthought which might explain our rainfall better

It seems the autumn break will never come. Days and nights are still warm to hot and rainfall is negligible. Plants that should be growing are sitting in limbo. Animals are getting desperate. I have even taken to watering drought-hardy natives in my garden, worried they might perish otherwise.

Here’s a quick snapshot of the last 12 months’ rainfall (such as it was) from two stations maintained by Melbourne Water, one in the north of town near the Darley golf club, and one just south, near the aerodrome. These are contrasted with the historic 1880-1962 monthly averages, which were measured near the Racecourse.

Bacchus Marsh 2018-19 rainfall

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Hooves and mouths (and fences): what impact do stock have?

I reviewed Charles Massy’s interesting book Call of the Reed Warbler and noted he provides a scientific reference for the contention that it is animals’ mouths, not hooves, that cause land degradation. I read the paper, and want to pick apart just what it shows, in relation to what Massy (and its own authors) say it shows. I think, at least as far as this reference goes, any claim that cell grazing techniques restore biodiversity is not demonstrated by the reference supplied. Continue reading

Where are the grassland remnants?

Just down the road, how about that.

Victorian Volcanic Plains Conservation Management News

We usually think to look for grassland remnants along roadsides and on rail reserves on the Victorian Volcanic Plain  Cemeteries are another good place to check out, but have you thought about going to church yard? At St George’s Church Balliang, there is tiny grassland treasure.

I was there on Wednesday chatting with a few people about what to look for and how to manage a remnant such as this one. As with most grassy remnants we need to manage the density of grass cover and this one needs a burn to open it up. Perhaps that will happen this autumn. You never know who has a little patch of grassland out the back. It is lovely to know this patch is in good hands.

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“Call of the Reed Warbler”

Book review: Call of the Reed Warbler – A new agriculture, a new earth
Charles Massy, University of Queensland Press, 2017

Charles Massy takes the reader on a meandering route through seemingly endless case studies of sustainable agricultural practice, mostly in Australia, in the manner of an aimless road trip or a sightseeing wander around a diverse farm. In fact, each chapter begins with him describing a bit about a particular trip to visit an inspirational agricultural innovator, or a walk through his back paddocks, before launching into the substantive matter of the chapter. It’s a slow way to tell a story but the book is worth reading as an introduction to many of the ideas available for making agriculture more sustainable, and the slow style is nevertheless readable and enjoyable.

This is a book of hope. Were I to rate it for the central premise, of making agriculture contribute to healing the world and ourselves, I’d give it five stars. Instead I give it 3.5, (rounded down to 3 – no half stars allowed – on Goodreads) because most other reviewers rated it so highly and I think it deserves a critical review. Critical, because it’s important, and influential, and deserves to be considered carefully — not because it should be ignored or written off. Continue reading

Reveg plastic pollution

Re-vegetation has the right aims, but the tools available, and their use, sometimes leave a lot to be desired. I’m thinking about the ubiquitous plastic tree guards, mainly (and a couple of other things mentioned at the end of this blog post). I wonder if anyone else has come up with solutions to any of these problems (leave a comment please! – EDIT: some suggestions are now available in the comments). Anyway since it’s new year coming up, lets make a resolution to reduce plastic pollution from revegetation in 2019.

Tree-guards have a purpose, which they fulfil more or less well, but the downsides are not usually addressed properly. The plastic corflute construction of the most commonly used types these days is sometimes a significant litter problem.

Plastic is one of the more obnoxious kinds of litter. Paper breaks down fairly quickly. Metal cans and glass are relatively inert (and more or less natural). Plastic, however, does not break down easily but nor is it inert. We know from many news stories now that it breaks up into micro-particles which can enter the food chain and may cause all sorts of problems.

There’s a lot of sources of litter, but environmental efforts like revegetation shouldn’t be one. And yet… they are. A lot of revegetation happens along waterways, in the flood zone, because that’s where you can’t clear for housing and other purposes (yes, as usual, ecology only gets what no-one else wants). What happens when it floods? Tree guards washed downstream. Continue reading

What’s in your layer cake?

Layer cake

Community volunteers planting trees is a great sign of people starting to care for the environment. But just planting trees does not equal restoring the environment. Ecologists tend to view vegetation as coming in structural layers, like a layer cake. The simplest scheme breaks it into three: Tree canopy, understorey (small trees and shrubs) and ground layer (grasses, herbs, logs and leaf litter).

5 structural layers in a woodland
The 5 structural layers in a woodland or dry forest. From www.recreatingthecountry.com.au

Unfortunately, some of these layers are easier to recreate than others, and the most difficult – the grassy ground layer – often gets left in the “too hard” category. So our layer cake might have great decorative icing, sturdy top layers of sponge and cream and whatever, but the bottom layer is unfortunately shit (weeds, more literally). Who wants to eat that layer cake? Continue reading