Anthropocene plant biodiversity data added to Selborne

Recently I added some data on terrestrial ecoregions to Selborne. It was a valuable addition but the information it conveys is not instinctively recognizable from the ground. For instance: it groups The Netherlands into one ecoregion with large parts of Denmark, Germany, Belgium and France. I wouldn't dare to argue with its justness as a concept but, from the point of view of an individual mapping his personal environment, ecoregions are an abstraction to the point of uselessness. Especially from a Dutch perspective where the 'Mixed Atlantic Forest' that it is supposed to contain simply does not exist.

A welcome addition to Selborne therefore is the 'Plant Biodiversity in the Anthropocene' data provided by Erle Ellis & colleagues at the Laboratory for Anthropogenic Landscape Ecology. I blogged about this earlier.

The original shapefile converted to a 12.8Mb GeoJSON file which I divided in 6 separate files each containing the data for each of the ecozones that the file provides (Palearctic, Nearctic, Neotropics, Afrotropics, Indo-Malay, Australasia). I had to split the Paleartic file again into North and South to keep file-size modest. Each file is between 1 and 3 Mb and is loaded as a layer on top of the standard map. Find the links in the menu under the logo under the datasets header. Give your browser time to parse.

What is nice about the data is that a lot of information is given for each area/cell/hexagon. When you load the data it will not give you the immediate visual buzz that makes maps attractive, but once you hover over a cell 13 different types of information are displayed.


There is information on main land use, land cover and population density. But the real meat of the thing is in the data on native species richness, species loss, and invasive/introduced species. By comparing data for each cells you can get a good view on where the human hand has been most effective in changing the native plant composition. 

The best source for detailed information on the data is the original paper.

This is data that to me appears to describe the world in a way that would be clearly visible if you were at a given area. 

It is possible to look at this data using the different maps Selborne offers under the layer-menu. Sudden jumps in numbers (be they for population density, urbanity or species richness) between adjacent cells can sometimes be understood by viewing it with a  topographic or relief map at the background.


My personal motivation for doing Selborne was the desire for a tool that would allow me to track invasive plants in my own neighbourhood and novel ecosystem/anthropocene work was what inspired me. So I am very happy with the inclusion of this data.   

Citation: Ellis, E. C., E. C. Antill, and H. Kreft. 2012. All is not loss: plant biodiversity in the Anthropocene. PLoS ONE 7:e30535. doi:10.1371/journal.pone.0030535.

Visit Selborne here, more info about Selborne here.

Novel tropical forests -> cryptoforestry

Ariel Lugo was one of the first to notice that second growth tropical forests invaded by exotic species were at least as efficient biodiverse as pristine forests. His 2009 paper 'The Emerging Era of Novel Tropical Forests' is only 3 pages but foundational. Here he describes the process from abandoned plantation to forest.

(1) The dominant tree species in the forests of Puerto Rico were mostly introduced species used by people for a variety of reasons.
 
(2) A diverse cohort of native tree species develops underneath the canopy of introduced species.
 
(3) Abandoned plantations of introduced species behaved like native forests and allowed the establishment of a rich understory of native species, which then mixed with the introduced species to form a different forest type than originally present.
 
(4) Experimental plantings of introduced species overcame arrested succession and native forest species reestablished below their canopy.
 
(5) Introduced tree species had the capacity to invade degraded lands while native pioneer species could not.
 
(6) Introduced tree species gained importance in island forests between 1982 and 2003.
 
(7) Introduced species were not randomly distributed on the landscape, but reflected past land uses, bioclimate, and substrate.
 
(8) Emerging forests had higher tree species richness than those that were native, and functioned as did native forests, but at different rates.

The entire paper is quotable but here is the conclusion:

Novel environmental conditions created by human activity favor the remixing of species and formation of novel forests. I expect novel forests to behave ecologically as native forests do, i.e., protect soil, cycle nutrients, support wildlife, store carbon, and maintaining watershed functions. Moreover, novel forests mitigate species extinctions as they, like secondary forests, are in successional paths to maturity and species accumulation. Nature’s response to the Homogeocene cannot continue to be ignored or remain undetected by ecologists. The dawn of the age of tropical novel forests is upon us and must not be ignored. 

Biodiversity in the Anthropocene

Following up on some links from an earlier post the following papers by Erle Ellis & various colleagues came up: 

1- Putting people in the map: anthropogenic biomes of the world (2008, PDF)

2- Anthropogenic transformation of the biomes, 1700 to 2000 (2010, PDF)

3- Anthropogenic transformation of the terrestrial biosphere (2011, PDF)

4- All Is Not Loss: Plant Biodiversity in the Anthropocene (2012, read this for a better understanding)

That's is a lot to take in. On one level the work is quantifying (with a lot of maps) "anthropogenic transformation of the terrestrial biosphere". On another level it uses the data to make statements on the need for new conceptual categories of land use.

Between 1700 and 2000, the terrestrial biosphere made the critical transition from mostly wild to mostly anthropogenic, passing the 50% mark early in the 20th century. At present, and ever more in the future, the form and process of terrestrial ecosystems in most biomes will be predominantly anthropogenic, the product of land use and other direct human interactions with ecosystems. Ecological research and conservation efforts in all but a few biomes would benefit from a primary focus on the novel remnant, recovering and managed ecosystems embedded within used lands.

But it is not all bad news:

Anthropogenic global changes in biodiversity are generally portrayed in terms of massive native species losses or invasions caused by recent human disturbance. Yet these biodiversity changes and others caused directly by human populations and their use of land tend to co-occur as long-term biodiversity change processes in the Anthropocene. Here we explore contemporary anthropogenic global patterns in vascular plant species richness at regional landscape scales by combining spatially explicit models and estimates for native species loss together with gains in exotics caused by species invasions and the introduction of agricultural domesticates and ornamental exotic plants. The patterns thus derived confirm that while native losses are likely significant across at least half of Earth's ice-free land, model predictions indicate that plant species richness has increased overall in most regional landscapes, mostly because species invasions tend to exceed native losses. 

There is a tool:

Anthropogenic species richness (ASR) results when humans interact with native patterns of species richness. Within a given area, ASR can be quantified as the sum of native species richness (N), anthropogenic loss of native species (ASL) and anthropogenic species increase (ASI). 

And there is a philosophical point:

Anthropogenic biomes point to a necessary turnaround in ecological science and education, especially for North Americans. Beginning with the first mention of ecology in school, the biosphere has long been depicted as being composed of natural biomes, perpetuating an outdated view of the world as “natural ecosystems with humans disturbing them”. Although this model has long been challenged by ecologists, ... it remains the mainstream view. Anthropogenic biomes tell a completely different story, one of “human systems, with natural ecosystems embedded within them”. This is no minor change in the story we tell our children and each other. Yet it is necessary for sustainable management of the biosphere in the 21st century. Anthropogenic biomes clearly show the inextricable intermingling of human and natural systems almost everywhere on Earth’s terrestrial surface, demonstrating that interactions between these systems can no longer be avoided in any substantial way. Moreover, human interactions with ecosystems mediated through the atmosphere (eg climate change) are even more pervasive and are disproportionately altering the areas least impacted by humans directly (polar and arid lands).

And there are also catch phrases:

The big picture: all is change

All is not loss: sustaining biodiversity in anthromes
The anthropogenic melting pots

Anthropogenic succession: thinning globally, enriching locally

Ecologists go home!

Globalization creates forests [in some places]

Quoting from an interview between the Yale environmental website e360 and Susanna Hecht on the positive effect globalization has on the regrowth of forests in El Salvador:

With globalization and structural adjustment programs, things like corn and other basic staples were coming in at import prices that were below the cost of their production in El Salvador. That meant if you were going to sell your corn, you would be selling it at a loss. So peasant agriculture soon collapsed, allowing reforestation.

Another thing about globalization is that for niche commodities it’s quite good. Those are crops that get a premium. What it meant in the case of El Salvador is that things like cashews and coffee and artisanal products made from wood had a vigorous market compared to the crummy returns you got for corn and the milpa crops [Subsistence crops such as beans and squash.] There was a shift to higher value crops, many of them arboreal.

More than half the households receive remittances from various countries, mostly from family members in the Los Angeles area. People work at jobs here in the U.S. and send money back. If you are getting remittances, you live a lot better — it basically doubles your income. Instead of having to produce corn with low yields on, say, steep slopes, you could buy the corn for the tortillas and not have to go into these forest areas. The result was a lot of land abandonment. The land was allowed to go into successional activities or forest-based economies rather than being used for producing basically corn.

The global market is against agriculture and the farmers themselves receive so much money from relatives abroad that they can retire from farming anyway! This is happening in Europe as well as noted earlier. But a secondary forest is not the same as a primal forest and lots of people are worried that Hecht's work in the wrong hands can give a rational for the deforestation of old growth forests. Earlier we quoted David Quammen warning that the invasion of weedy species and the decline of local biodiversity creates unwanted international uniformity. Hecht responds to this in a way that with a bit of effort could still be interpreted as dismissing concerns over deforestation be positively addressing the biodiversity of second growth forests. I wonder if the second growth forests of El Salvador can be understood as novel ecosystems. 

I am always surprised how controversial this is. I think it’s partly because some conservationists don’t count secondary forest as real forest. They see forests as ahistorical and apolitical, and the forests just aren’t. It was pounded into people in Bio 101 that human interaction with forests is destructive. But there has been extensive human influence even in places like the Amazon. What my work there taught me is that these places weren’t empty, and that if you only look at the ecological side, you don’t see the social side of forests. The conservationists really don’t like this.

What helped me to see forests in degraded areas was being around people messing in the forest. So I was primed to see the El Salvador forests and not to disparage them. To me there is almost no primary forest; it’s all secondary forests. All landscapes will have to be working landscapes. If we have lots of people with forests, we should be thrilled. And we should be really thrilled when the forest comes back because we have a narrative that it doesn’t come back.

There has been a recognition that inhabited environments can have major conservation value. Even though the reforested areas are fragmented, they are quite diverse in terms of landscape. They end up actually having a rather interesting impact at regional levels — they scale up rather better than one might imagine. Even those hedgerows can provide something like 40 to 50 percent of the biodiversity that you get in a riparian system in El Salvador. And hedgerows, land demarcations, woodlots, gardens and domestic forests of various kinds all end up supporting biodiversity in ways that are kind of surprising. For instance, the bird diversity of El Salvador is about equal to that of Belize, which has a fraction of the population and far less fragmented forests.

The image comes from Hecht's paper 'Globalization and Forest Resurgence: Changes in Forest Cover in El Salvador'

Novel ecosystems [the science behind cryptoforestry]

16 names have signed 'Novel ecosystems: theoretical and management aspects of the new ecological world order'. It's something of a manifesto arguing for a new approach within ecology to the newly emerging landscapes of the anthropocene. The image is from a 2009 article in Nature on novel ecosystems as Raggamuffin Earth.

Most of the world’s ecosystems are now impacted by humans to a greater or lesser extent, and humans thus play an important role in modifying or regulating the types and rates of ecosystem change. In addition, global trading has breached biogeographical boundaries and facilitated the spread of species into regions that they would probably never have reached under normal
conditions.

Novel ecosystems (also termed ‘emerging ecosystems’) have species compositions and relative abundances that have not occurred previously within a given biome. The key characteristics are  (1) novelty: new species combinations, with the potential for changes in ecosystem functioning; and  (2) human agency: ecosystems that are the result of deliberate or inadvertent human action, but do not depend on continued human intervention for their maintenance. Such ecosystems result from biotic response to human-induced abiotic conditions and/or novel biotic elements (e.g. land degradation, enrichment of soil fertility, introduction of invasive species). This includes the cessation of management of systems that have been managed or created by humans (e.g. agroforestry systems, pastoral land). New species combinations arise frequently in today’s world in conditions of strong direct or indirect human impact. In particular, there are three main reasons for their existence.

1 - Human impact has resulted in local extinction of most of the original animal, plant and microbial populations and/or the introduction of a suite of species not previously present in that biogeographical region.
2 - Predominating urban, cultivated or degraded landscapes around target ecosystems create dispersal barriers for many animal, plant and microbial species.
3 - Direct (e.g. removal of natural soil, dam construction, harvesting, pollution) and indirect (e.g. erosion due to lack of vegetation or overgrazing) human impact has resulted either in major changes in the abiotic environment or a decrease in the original propagule species pool, both of which can prevent the re-establishment of pre-existing species assemblages.

These types of ecosystem can be thought of as occupying a zone somewhere in the middle of the gradient between ‘natural’ or ‘wild’ ecosystems, on one hand, and intensively managed systems on the other hand.