It’s not easy to characterise the local environment of species living in mountains because these habitats are highly heterogeneous. At a large scale, we typically assume that temperature varies with altitude, but at a local scale, we understand that exposure to wind or being in the shade has a great influence on climatic conditions. If you go from the south-facing to the north-facing side of a mountain, it can be easily 5°C colder. If we can feel that, so can the organisms that live up there. Plants in particular are submitted to tremendous climatic variations over a year. What we want to know is: how did they adapt to these climatic variations and how localised is their adaptation?
Overcoming the Challenges of Measuring Local Adaptation
We don’t know much about how organisms adapt locally because it’s so difficult to measure the environmental conditions that these plants are facing. Existing weather stations can’t capture micro-habitat conditions because they are few and far between. What we can do instead, is use topographic models of mountains to model their environment. After all, if orientation, slope or shade have an impact on climatic conditions, why couldn’t we use them to model local variations in temperature for example? Continue reading →
I have always loved the Blue Marble image of Earth from the Apollo 17 mission, yet a large part of my science is focused on experimental responses at the scale of meter squared grassland plots or even individual grass plants. While I spent my early career wanting to be able to say something important about regional or global processes, I found myself feeling like generating any experimental insights into processes and ecosystem responses at larger scales would be an impossible fiction.
As a postdoc, I had the opportunity to do a multi-site study across a north-south precipitation gradient in California and jumped at it. Among other questions, I decided to ask about whether plants and insects varied similarly across sites in response to replicated experimental treatments. Yet, the idea of actually sampling – and then processing samples from – more than about four sites for more than a year or two was utterly daunting. Continue reading →
To truly understand how species’ distributions vary through space and time, biogeographers often have to make use of analytical techniques from a wide array of disciplines. As such, these papers cover advances in fields such as evolutionary analysis, biodiversity definitions, species distribution modelling, remote sensing and more. They also reflect the growing understanding that biogeography can include experiments and highlight the increasing number of software packages focused towards biogeography.
This Virtual Issue was compiled by Methods in Ecology and Evolution Associate Editors Pedro Peres-Neto and Will Pearse (both of whom are involved in the conference). All of the articles in this Virtual Issue are free for a limited time and we have a little bit more information about each of the papers included here: Continue reading →
How many samples do you hope to collect on your next field assignment? 50, 100 or 1000? How about billions. It may seem overly optimistic, but that’s the reality when using Light Detection and Ranging, or LiDAR.
LiDAR works on the principle of firing hundreds of thousands of laser pulses a second that measure the distance to an intercepting surface. This harmless barrage of light creates a highly accurate 3D image of the target – whether it’s an elephant, a Cambodian temple or pedestrians walking down the street. LiDAR has made the news over recent years for its ability to unearth ancient temples through thick jungle, but for those of us with an ecological motive it is the otherwise impenetrable cloak of vegetation which is of more interest.
It’s very hard to make sensible choices without sensible information. When it comes to actions around changing land use and its ecological impact though, this is often what we are forced to do. If we want to reduce the impact of human activities on natural ecosystems, we need to know how much change has already occurred and how altered an ecosystem might be from its “natural” state.
Working out which parts of the landscape have been changed and mapping the absence of natural vegetation is an achievable (though onerous) task. However, moving beyond this binary view of the world is a huge challenge. Pretty much all habitat has been modified by human influences to some extent – by, for example, wood extraction, the introduction of invasive species or livestock grazing. This means that a lot of the apparently native habitat is no longer capable of supporting its full complement of native biodiversity. Continue reading →
In the UK, National Tree Week (26 November – 4 December) celebrates tree planting within local communities. The latest BES cross-journal Virtual Issue contains recent papers that highlight the global importance of trees and forests as habitat – for species from insects to primates – and in meeting human needs for fuel and agriculture. The selected papers also demonstrate novel methods scientists are using to study trees and forests.
National Tree Week is the UK’s largest tree celebration. It was started in 1975 by the Tree Council and has grown into an event that brings hundreds of organisations together to mark the beginning of Britain’s winter tree planting season.
Landscape connectivity is important for the ecology and genetics of populations threatened by climate change and habitat fragmentation. To begin our Virtual Issue Rayfield et al. present a method for identifying a multipurpose network of forest patches that promotes both short- and long-range connectivity. Their approach can be tailored to local, regional and continental conservation initiatives to protect essential species movements that will allow biodiversity to persist in a changing climate. The authors illustrate their method in the agroecosystem bordered by the Laurentian and Appalachian mountain ranges, that surrounds Montreal.
Every species in the world has a unique geographic distribution. But many species have similar ranges. There are many things that can cause two (or more) species to have similar ranges – for example shared evolutionary histories, physical obstacles (mountains, oceans etc.) or ecological barriers limiting their dispersal. As a consequence, different regions of the globe are inhabited by different sets of living organisms.
In the mid-19th century ecologists recognised that the earth could be divided into different biogeographic regions. Alfred Russel Wallace (1823–1913) played a key role in defining and recognising biogeographic regions. He improved the existing maps of biogeographic regions and provided basic rules to identify them. His observation that some of these regions are home to similar species, despite being far away from each other and separated by significant barriers was the inspiration for Alfred Wegener’s theory of continental drift. In more recent years regionalisation has been used to understand the spatial drivers of biological evolution and to protect those regions characterised by particularly unique flora and fauna.
The biogeographic regions identified by Alfred Russel Wallace from The Geographical Distribution of Animals (1876)
At the last ISEC, in Montpellier in 2014, an informal survey suggested that Methods in Ecology and Evolution was the most cited journal in talks. This reflects the importance of statistical methods in ecology and it is one reason for the success of the journal. For this year’s International Statistcal Ecology Conference in Seattle we have produced a virtual issue that presents some of our best recent papers which cross the divide between statistics and ecology. They range over most of the topics covered at ISEC, from statistical theory to abundance estimation and distance sampling.
We hope that Methods in Ecology and Evolution will be equally well represented in talks in Seattle, and also – just as in Montpellier – some of the work presented will find its way into the pages of the journal in the future.
In order to help prioritizing conservation efforts, the International Union for Conservation of Nature (IUCN) has published criteria to categorize the status of threatened species, which are then published in Red Lists. Changes in a species’ geographical distribution is one of the several criteria used to assign a threat status. For rare species, however, the exact distribution is often inadequately known. In conservation science, Species Distribution Models (SDMs) have recurrently been used to estimate the potential distribution of rare or insufficiently sampled species. Continue reading →
Friday was Endangered Species Day – so this is a good time to reflect on what science and scientists can do to support conservation efforts and to reduce the rate of species extinctions. One obvious answer is that we need to study endangered species to understand their habitat requirements as well as their potential for acclimatization and adaptation to changing environmental conditions. This information is crucial to for the design of informed conservation planning. However, for most endangered species the relevant phenotypes are not known a priori, which leaves the well-intentioned scientist asking “which traits should I measure?”. Transcriptome analysis is often a good way to answer to this question.