managing grasslands ecosystems in a changing climate: opportunities for mitigation and adaptation...

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Managing Grasslands Ecosystems in a Changing Climate: opportunities for mitigation

and adaptation

Adriana Dinu, Regional Practice Leader, Environment and Energy, Europe and CIS

Grasslands are important to livelihoods....

20% converted to crops

25% of milk production

23% of beef production

Livestock industry – 1 billion poorest people; 1/3 of global protein intake

3.5 billion ha

26% of the world land area

70% of the world agricultural area

20% of the world’s carbon stocks

Grasslands are vulnerable to ....

Climate change - most of any terrestrial ecosystem (Sala et al., 2000; IPCC, 2001a).

Invasive species - especially following disturbance, due to low-stature of vegetation conferring high light availability – natural vulnerability

Vegetation change - if the changes to temperatures and precipitation are sufficient to alter biomass and fire frequency

World’s Temperate Grasslands – most threatened, least protected

Only 5% protected!

Geographical coverage of steppe ecosystems

Macin NPRomania

Steppe PAsKazakhstan

Steppe PAsRussia

Steppe PAsTurkey

Working with oil sector

Uzbekistan

Threats to Grasslands: Livestock grazing Major land use of the world’s remaining grasslands (IPCC, 2001a)

Compacts soils, reduces infiltration and soil water capacity, dries out surface soils, increasing vulnerability to drought and accelerate desertification.

Degrades riparian habitats - hot spots of native biodiversity; connectivity between grassland patches;

Localized increases in soil fertility in areas of concentration - vegetation in nutrient hot spots is dominated by IS : foci for further invasion

Erosion, topsoil loss and destroys biological soil crusts critical for soil fertility

СО2 emissions: 0.3-0.9 t/ha

Grasslands exposed to over-grazing

Original stateHigh biodiversity

Native grassGrass dominated system

High economic value

Altered stateLow biodiversity

Invasive species – weedsShrub dominate system

Low economic valueEven when grazing pressure is relaxed, there may be little change in composition, because of the advantage of woody vegetation over grass when the woody is dominant

Threats to Grasslands: Agriculture conversion

Isolation leaves grassland species little room to migrate in response to CC;

Changes in the level of surface water evaporation alters regional climate influencing plant community composition

Decline in soil carbon stocks by 60%

Turning into croplands: 1 Million ha after 2007 in Russia

Threats to Grasslands: Alterations of fire regimes

Shortening of the fire return interval due to invasions has favored fire-tolerant plant species, resulting in the loss of fire-intolerant bunchgrasses, shrubs, and wildlife

Accelerated nutrient losses through volatilization and mortality of biological crust organisms;

Fuel breaks created to suppress fire may act as conduits for the spread of invasive species

78-84% world’s springtime black carbon, nationwide 30 million ha burning annually in Russia

Increases of atmospheric CO2 impact on grasslands:

Depends on:

The mix of C3 vs. C4 species:Plants with the C3 photosynthetic pathway (e.g., Stipa spp.) may increase photosynthetic rates and show enhanced growth rates as CO2 concentrations increase.

Location: ecotonal habitats -most likely to experience vegetation changes

Increases of atmospheric CO2 impact on grasslands:

Leads to:

An increase of water use efficiency of plants: reduced time needed to have stomata open for CO2 uptake; Increase soil moisture, may negatively impact grasslands where conditions favor invasive species

Large scale vegetation change: as the current species composition in most grasslands often includes introduced species

Managing Grasslands for Resilience to Climate Change ....what we need to know?

Vigorous stands of native vegetation: roots have access to deeper soil moisture and are better able to compete with invasive species

Healthy plant cover intercepts rainfall, maximizing infiltration and soil water supply, reducing overland flow, and preventing nutrient losses due to erosion

Healthy level of soil organic matter: important for soil aggregate formation, fertility, stability, water movement and holding capacity,

Abundance and relative composition of plant species depend on ecological processes such as herbivory and fire.

Include all grassland types across environmental gradients in protected areas: as we do not know precisely which grassland types will be most sensitive to CC

Climate Change Adaptation Options in Grasslands

Improved Connectivity: to facilitate the migration of species in response to CC - where it is critical for maintaining gene flow among populations of rare species

Protect relict and native-dominated communities: as models for habitat restoration and help in understanding how grasslands altered vs. unaltered are affected by CC.

Minimize fragmentation by land use changes and roads: protect core grassland habitats distant from roads and human disturbances as they are often refuges for native species; time road maintenance to avoid spread of invasives; monitor roadside vegetation.

Low-intensity, sustainable grazing practices: where native species are adapted to it; Reduce/remove grazing from sites where the predominant native species lack a long evolutionary history of grazing by large hooved herbivores; Maintain heterogeneity of management at the landscape and mimic grazing patterns of native herbivores;

Prevent and control the spread of invasive species:

Focus on the causes of invasion - seed sources and disturbances that increase vulnerability to invasion.


Restoration: including reintroductions of native species, IAS control, inoculations with soil biota important to native plant vigor, nutrient cycling and restoration of native disturbance regimes


Maintenance of natural fire regimes: as it is influencing the health and heterogeneity of grassland vegetation


Provide buffer zones: provide suitable conditions for shifting of populations to lands bordering reserves as conditions inside reserves become unsuitable; act as barriers to the spread of new invaders away from roads.


Identify and protect functional groups and keystone species: increased tolerance to environmental extremes and recovery potential as native species richness or cover increases.


Protect climatic refugia at multiple scales: identify past climatic refugia and focus conservation efforts on these areas so they can again function as refugia during present and future CC


Carbon sequestration in Grasslands Disturbance through removing of biomass, changing vegetation – is an integral part of traditional grassland management system

Disturbance through overgrazing, fire, invasives can deplete grasslands of carbon stocks

Biomass : herbaceous; TRANSIENT CARBON POOLSoils: DOMINANT CARBON pool

Much of Carbon lost from agricultural land soil and biomass pools can be recovered with changes in management practices that increase carbon inputs, stabilize carbon

within the system or reduce carbon losses.

Managing Grasslands for Carbon sequestration:Practices that sequester carbon often enhance productivity

Improved Grazing Management - that maximizes production- Increases C stocks by approx. 0.35 Mg C/ha/year- Most of the potential sequestration

Sowing Improved species: better adapted to local climate, resilient to grazing, resistant to drought

Restoring degraded lands: enhances production in areas with low productivity , increasing carbon inputs and sequestering carbon

Including Grass in the rotation cycle – have the largest impact on soil carbon

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managing grasslands ecosystems in a changing climate: opportunities for mitigation and adaptation...

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