Tuesday 31 May 2016

Climate change and plant growth (journal)




Vegetation productivity responds to sub-annual climate conditions across semiarid biomes

This is an open-access paper - free to all.

 I know it can be daunting reading a scientific paper that is not in your specialised area, so I've added a summary below and a couple of hints on key knowledge to help those who want it. - Naomi.

Article summary
One predicted impact of climate change is longer and more frequent droughts in some areas of the world.  The timing of rainfall both over one year (within-year / intra-annual) and over many years (inter-annual) is important in understanding how plant communities might respond.

In this journal paper, researchers looked at responses of grassland, shrubland and forest communities in the semi-arid southwestern USA to prolonged drought.  They found that:

  • Production in all biomes was impacted by rainfall and temperature
  • Higher rainfall is linked with higher production.
  • Critical timescales (when production is most affected by temperature and rainfall) are:
    • Forests  - January through to September.  
    • Shrubland - July and August.  
    • Grassland - July through to September
  • Production in forests was driven by winter precipitation (which replenishes soil moisture) and limited by maximum summer temperatures.
  • Production for shrubs and grassland was driven by summer rainfall and limited by high daily maximum temperatures in summer
  • Plant growth increases as temperatures increase to a maximum daily temperature of ~17 degrees C and then rapidly declines when maximum temperatures rise above that.
  • It is important to consider both temperature and precipitation patterns when seeking to understand vegetation responses.


Key knowledge and terms used
The balance between temperature and rainfall is directly linked to the kinds of plants that can thrive and ultimately can define biomes at a global level.  The hotter it is, the more water a plant needs to use (through evapotranspiration).  Broadly speaking - Little rainfall = desert, (high temp like Sahara or low temp like Antarctica);  Lots of water and cool temperature = temperature forest; Moderate water and cool temperature = temperate grasslands; Lots of water and high temperature = tropical rainforest.

This paper uses a way of measuring this balance temperature and rainfall called Standardised Precipitation Evapotranspiration Index (SPEI).

Enhanced Vegetation Index (EVI) is a proxy measure of plant growth - it uses satellite data to detect small changes in colour (greenness)


Links to permaculture
Can we use knowledge from natural communities to think about how our natural ecosystems and/or annual crops and forest gardens might respond and how we could adapt?  When might be critical to store/use water?

Thursday 26 May 2016

Integrated farming gives productivity AND ecosystems (#journal)

Soil functions and ecosystem services in conventional, conservation, and integrated agricultural systems. A review

This study reviewed relevant bibliography and then developed a simple conceptual model, in which soil functions and ecosystem services were compared between conventional, conservation, and integrated agricultural systems. The overall agro-environmental score was largest for conservation systems (71.9 %), intermediate for integrated systems (68.8 %), and smallest for conventional systems (52.1 %). But the crop yield productivity score was largest for integrated systems (83.3 %), intermediate for conventional systems (66.7 %), and smallest for conservation systems (58.3 %). This study shows the potential of integrated farming systems in global food security while sustaining environmental quality.

Bio-integrated farming (book)

The Bio-Integrated Farm is a must-read, twenty-first-century manual for managing natural resources and brings system farming and permaculture to a whole new level. Jadrnicek’s groundbreaking insights into permaculture go beyond the term’s philosophical foundation to create hardworking farm-scale designs. Jadrnicek’s components serve at least seven functions. With every additional function that a component performs, the design becomes more advanced and saves even more energy. A bio-integrated greenhouse, for example, doesn’t just extend the season for growing vegetables; it also serves as a rainwater collector, a pond site, an aquaponics system, and a heat generator.

 

Permaculture in landscape architecture (thesis)

An Instructional Module on Permaculture Design Theory for Landscape Architecture Students 

Permaculture offers a unique set of design principles that are very implementable into the design process and could be of great interest to landscape architects. The purpose of this study was to develop and implement an instructional module for landscape architecture students at Utah State University for two consecutive years. Project-based learning was implemented in order to help students better understand permaculture design theory. Effectiveness of the module was measured through an evaluation of post-module survey responses and student design projects. Results from the second year of teaching showed an increase from the first year in student interest, understanding, and desire to learn more about permaculture design theory.

Permaculture in urban Alaska (book chapter)

Applying Permaculture in Alaska: The Williams Street Farmhouse

Saskia Essinger and Matt Oster turned the small barren lot surrounding their home into an urban oasis in the challenging climatic conditions of Anchorage, Alaska. They utilized permaculture principles to design a beautiful, low maintenance garden that provides much of their vegetables and fruits throughout the year. Their garden was so successful that they undertook a challenge to eat entirely local for a year, with a significant proportion coming from their own property, proving that an all-Alaskan diet is possible.

Feeding India without pesticides (journal)

This Review article is a genuine attempt to evaluate the possibilities of the negligible use of pesticides in agriculture in India. Though India is among the least users of pesticides, even then for the sustainable agricultural output there are the possibilities of alternative agricultural practices. Moreover, the authorities are not so serious about this subject therefore the modern technologies are not being welcomed for agro-ecology. This article is based upon the secondary data available in the published reports. The article will conclude that the inclusive growth in agriculture is the need of the hour in India. It is argued that the alternative agriculture must be adopted for the overall welfare of future of the humanity.

Monday 23 May 2016

Climate change impact on the cost of living (report)


This new report examines how climate change could affect day to day living costs of UK households. A key finding is that low income households will be most affected by climate change impacts on the costs of living. The food bill for an average household could rise by 9% by the 2050s and this will have a bigger impact on low income households, because their average household spending on food is higher. There are also large costs for those affected by increased flooding, especially for those without insurance which many low income households lack. In addition, there are higher risks of flooding in many deprived areas.

Thursday 19 May 2016

Soil management to mitigate climate change (journal paper)

Climate-smart soils

Improved soil management can substantially reduce greenhouse gas emissions from soils and sequester some of the carbon dioxide removed from the atmosphere by plants, as carbon (C) in soil organic matter. In addition, wise soil management that increases organic matter and tightens the soil nitrogen (N) cycle can yield powerful synergies, such as enhanced fertility and productivity, increased soil biodiversity, reduced erosion, runoff and water pollution, and can help buffer crop and pasture systems against the impacts of climate change. This article highlights ‘state of the art’ soil greenhouse gas research, summarises mitigation practices and potentials, identifies gaps in data and understanding and suggests ways to close such gaps through new research, technology and collaboration.

If you'd like some less technical reading, you might enjoy this summary article.

Although soils contribute a major share (37%; mainly as N2O and CH4) of agricultural emissions3, improved soil management can substantially reduce these emissions and sequester some of the CO2 removed from the atmosphere by plants, as carbon (C) in soil organic matter (in this Perspective, our discussion of soil C refers solely to organic C). In addition to decreasing GHG emissions and sequestering C,  wise soil management that increases organic matter and tightens the soil nitrogen (N) cycle can yield powerful synergies, such as enhanced fertility and productivity, increased soil biodiversity, reduced erosion, runoff and water pollution, and can help buffer crop and pasture systems against the impacts of climate change4.Although soils contribute a major share (37%; mainly
as N
2
O and CH
4
) of agricultural emissions
3
, improved soil management
can substantially reduce these emissions and sequester some of the CO
2
removed from the atmosphere by plants, as carbon (C) in soil organic
matter (in this Perspective, our discussion of soil C refers solely to
organic C). In addition to decreasing GHG emissions and sequestering C,
wise soil management that increases organic matter and tightens the
soil nitrogen (N) cycle can yield powerful synergies, such as enhanced
fertility and productivity, increased soil biodiversity, reduced erosion,
runoff and water pollution, and can help buffer crop and pasture systems
against the impacts of climate change
4
.

Although soils contribute a major share (37%; mainly
as N
2
O and CH
4
) of agricultural emissions
3
, improved soil management
can substantially reduce these emissions and sequester some of the CO
2
removed from the atmosphere by plants, as carbon (C) in soil organic
matter (in this Perspective, our discussion of soil C refers solely to
organic C). In addition to decreasing GHG emissions and sequestering C,
wise soil management that increases organic matter and tightens the
soil nitrogen (N) cycle can yield powerful synergies, such as enhanced
fertility and productivity, increased soil biodiversity, reduced erosion,
runoff and water pollution, and can help buffer crop and pasture systems
against the impacts of climate change
4
.