why dryland ecosystems matter -...

SUSTAINABLE SCIENCE FOR LIFE.SM University of Nevada, Reno

— College of — Agriculture, Biotechnology

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WHY DRYLAND ECOSYSTEMS MATTER

William Payne University of Nevada Reno



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WHAT DO WE MEAN BY “DRYLANDS”?

The term “drylands” is an internationally used term for water-stressed environments, but there is no single, universally accepted definition.

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• West African Sahel and Dryland Savannas

• East and Southern Africa

• Southern Asia • Northern Africa

and West Asia • Central Asia

CGIAR Dryland Systems Research Program

One Definition: Aridity Index

FAO definition Aridity Index range Arid 0.05 - 0.2 Semi-arid 0.2 - 0.5 Dry sub-humid 0.5 - 0.65

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Aridity Index ranges used by FAO to define drylands

Aridity Index (AI) = P / PET where: P = average annual precipitation PET = potential evapotranspiration

Another Definition: Length of Growing Period

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Length of growing period = number of growing days per year Growing day = day in which average air temperature exceeds a defined level and ratio of actual to potential evapotranspiration exceeds a defined level Growing period or ‘‘season’’ starts as soon as a specified minimum number of consecutive growing days has occurred (e.g., 5 days). Growing period or ‘‘season’’ ends once a specified maximum number of consecutive non-growing days (or ‘‘stress’’ days) has occurred (e.g., 12 days) Once a season has started, a day is designated a ‘‘stress day’’ if the temperature and evapotranspiration conditions above are not met

How closely are AI and LGP correlated?

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Arid

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AI and LGP for Pastoral Systems in Sub-Saharan Africa

SRT2

SRT3

SRT3 (?)

Length of Growing Period

Important to remember Regardless of the criteria used, “drylands” is a moving target, since it changes from year to year

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2006 2010 2012

MODIS phenology based on length of growing period



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WHY DRYLANDS MATTER TO ME • Horticulture Extension Agent in Mauritania • MSc Research (Soil Physics) in Niger • Crop Stress Physiologist (ICRISAT) in Niger • Dryland Systems Agronomist in East Oregon • Crop Stress Physiologist in Amarillo TX • Research Director (N.E. Borlaug Institute for

International Agriculture) • McKnight Foundation Liaison for West African

Sahel • Dryland Systems Director for CGIAR (25 countries) • Chair of Scientific Advisory Committee to UNCCD • Dean of Ag at UNR, in driest state in U.S.

WHY DRYLANDS MATTER TO CABNR AND

UNR

Land grants represent Successful Federal-State Partnership geared towards practical problem solving

• Morrill Act of 1862 (Teaching) • Hatch Act of 1887 (Research) • Smith-Lever Act of 1914 (Extension)



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PUBLIC LAND DISTRIBUTION IN THE USA AND NV

RESEARCH and TEACHING

• Alternative Crops and Forages • Plant and animal genetics • Soil and Water • Forest and Woodlands • Rangelands • Wildlife • Veterinary Science • Human Nutrition • Business and Economics

OUTREACH WORKSHOPS

• Drought assistance for agricultural producers • Native American waters on arid lands • Grazing management in drought years • Weed control extravaganza • Beginning farmer and rancher WEBSITE • Living with Drought

http://www.unce.unr.edu/programs/sites/drought/

EXTENSION WORKSHOPS

• Drought assistance for agricultural producers • Native American waters on arid lands • Grazing management in drought years • Weed control extravaganza • Beginning farmer and rancher WEBSITE • Living with Drought

http://www.unce.unr.edu/programs/sites/drought/

Western agriculture is dependent on utilization of public land

Recreation and visitations are also important “multi-use” considerations



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Hardin, G. 1968. The tragedy of the commons. Science 16:1243-1248



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“Each man is locked into a system that compels him to increase his herd without limit--in a world that is limited”

• Each family puts one cow out on the commons • Then somebody gets the idea to put two cows out

and does so • Then everybody else also puts two cows out, and so

forth. • As this process continues, the number of cattle

gradually increases tremendously. People can see that the range is deteriorating, but they keep adding cattle anyway.



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Land Degradation, Desertification, and Agriculture

Land Degradation: “the reduction in the capacity of the land to perform ecosystem functions and services that support society and development” (FAO, 2007).

Desertification: “... intensification or extension of characteristic desert conditions; the process entails a reduction in biological activity and plant biomass, in livestock carrying potential of land, in agricultural yields and a decline or degradation in man's living conditions" (FAO, 1993).

• Cultivation of soils that are fragile, or exposed to erosion by wind or water;

• Reduction in the fallow period of soils, and lack of organic or mineral fertilizers;

• Overgrazing - often selectively - of shrubs, herbs and grasses; • Overexploitation of woody resources, in particular for fuelwood; • Uncontrolled use of fire for regenerating pasture, for hunting, for

agricultural clearing, or for settling certain social conflicts; • Agricultural practices that destroy the soil structure, especially the

use of unsuitable agricultural machinery; • Agricultural practices that result in the net export of soil nutrients,

leading to loss of the soil fertility, such as cash-cropping; • Diversion of rivers to create irrigation schemes; and • Irrigation of soils prone to salinization, alkalinization or even

waterlogging.

Human Activities That Initiate Desertification



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• Since the passage of the Taylor Grazing Act, the number of animal unit months (AUM) permitted by federal agencies has declined dramatically, and continues to do so.

• According to the Department of Interior’s Fact Sheet on Management of Livestock Grazing, “Grazing use on public lands has declined from 18.2 million AUMs in 1954 to 8.5 million AUMs in 2013” (DOI, 2015).

• In Nevada, federal land AUMs fell between 1980 and 1999 by 473,553, or 16%, with a corresponding negative economic impact of $24,800,000 on the state, which fell disproportionally on rural economies (RCI, 2001)

Hardin: “The management of Western range lands, though nominally rational, is in fact (under the steady pressure of cattle ranchers) often merely a government-sanctioned system of the commons, drifting toward ultimate ruin for both the rangelands and the residual enterprisers.”



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National Public Lands Grazing Campaign: “The best science has demonstrated that any livestock grazing is detrimental to native ecosystems”

Western Watersheds Project: “Despite the extensive scientific literature describing the destructive impacts of public lands ranching, public land managers fail to enforce existing environmental laws usually because of political interference.”

Center for Biological Diversity: ”…overgrazing of fire-carrying grasses has starved some western forests of fire, making them overly dense and prone to unnaturally severe fires”

Some environmental groups that claim that any grazing by cattle or sheep on public lands constitutes overgrazing



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• There is a very large body of scientific evidence that shows that “properly managed” grazing can: • Restore ecosystems, • Improve quality and functioning of soils • Reduce wildfire severity by controlling fuel loads • Improve riparian zones, control invasive species • Enhance biodiversity

• The notion that grazing can be an environmentally

friendly and cost-effective way to enhance habitat for wildlife and preserve nature is widely accepted internationally (English Nature, 2005 ; UNEP, 2014).

Emotions and marketing often trump science in a litigious society less and less familiar with science or agriculture

Beaver Creek in 1985 after annual season-long grazing and in 1998 with rest and periodic short-term hot season and early season grazing by cow-calf pairs beginning in 1988.



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Preferable: • Uniform long term monitoring methods for all agencies (i.e., standard monitoring methods for all

agencies). • Use ecologically -based, modern monitoring methods (e.g. remote sensing) appropriate to

ecosystems of Nevada (as recommended by Nevada rangeland scientists). Actual: • Qualitative indicators, which are highly subjective, are often used and implemented differently

among districts (Pellant et al., 2005) • Different methodologies used by different agencies • Despite the recommendations of the scientific community, monitoring is based on short term, or

utilization monitoring, which often leads to reduction or loss of AUMs • Some use of remote sensing (e.g. U.S. Drought Monitor and VegDRI) but at a spatial scale that is is

extremely coarse; an inability to detect soil moisture drought or recovery at shorter timescales

HOW DO WE MONITOR GRAZING TO ASSURE THAT DESERTIFICATION DOES NOT OCCUR OR IS REVERSED?



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GREATER RELIANCE ON REMOTE SENSING FOR REAL TIME, LONG-TERM, HIGHER RESOLUTION, AND OBJECTIVE OBSERVATIONS



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• Mechanistic modeling offers another approach to assessing desertification and its response to management include simulation modeling.

• The USDA NRCS and Texas A&M have used the APEX

model, along with on-farm surveys and historical data, to quantify past conservation effort effects, and recommend future conservation practices on agricultural land.

• The study showed that that farmers reduced total cropland erosion caused by wind and water by 43 percent between 1982 and 2007.

• Models of this type need to be extended to rangeland conditions for testing and utilization.

Simulation Modeling



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• Hardin (1968) believed that tragedies of the commons have no technical solutions but instead require changes in human attitudes and behavior. The only two solutions were 1) the private enterprise system or 2) “socialism,” i.e. control by government (Hardin, 1978; Feeny et al., 1998).

• Privatization of U.S. western public lands seems dubious, although there are repeated efforts by some western states to transfer large amounts of public lands.

• The current method of control, “socialism” through control of federal agencies, is constantly subject to litigation by entrenched political adversaries, and therefore very slow to change or adapt.

• “Socialism” does not appear to achieve sustainable land management based on increased catastrophic fires and invasive species, poorer habitat quality, unsustainable number of horses, and other manifestations (Miller and Narayanan, 2008).

Better Governance of the Commons



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• Faced uncertain and complex environments • Shared a past and expected to share a future • Found it important to maintain their

reputations as reliable members of the community.

• Shared other similarities including sheer perseverance, and reliance on rules defining when, where, and how an individual’s allotted resource units could be harvested.

Local Action as a Societal Answer

Nobel Prize Laureate Elinor Ostrom’s (1990) analysis of similarities among several long enduring, self-governing common pool resource. She found that all:



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• There are many examples in the West of such Common-Pool Resource management approaches to improve rangeland productivity and ecosystem functioning

• One is the Stewardship Alliance of Northeast Nevada (SANE), a group of landowners who strive to improve sage-grouse habitat (Nature Notes, 2013) through on-the-ground habitat projects. Together, they own or lease 0.7 million ha of prime sage-grouse habitat, including BLM and FS allotments.

• The group uses a landscape and watershed approach to land management to benefit all animals that depend on sagebrush, and at the same time help their own ranch operations.

• Group members include personnel from federal agencies, state agencies, UNR, and conservation groups

Local Action as a Societal Answer



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WHY SHOULD DRYLAND ECOSYSTEMS MATTER TO THE US?

• Social and political stability, food security, and agricultural production are related in undoubtedly complex ways

• 1970 Nobel Peace Laureate Norman Borlaug: "As long as there are suffering and lack of food, there will be political uprisings and people killing each other"

• 1949 Nobel Peace Laureate Lord John Boyd Orr: "You cannot build peace on empty stomachs."

Tsunami (or Haboob) • 2 more billion to feed by 2050 • Already a billion hungry • Malnutrition much higher still especially

among children • Global agricultural production needs to

increase 70 percent by 2050 • Output in developing countries will have to

double • With less water • Under harsher climate • Sustainably

• For most countries sustaining per capita water availability will be an impossibly huge challenge. • As a result of population growth alone, water availability in the region is projected to decline to 400

cubic meters per capita by 2050. • Iraq is expected to see the largest drop in water availability, at 60 percent, but Djibouti, Jordan,

Sudan, and Syria are also projected to experience declines in availability in excess of 50 percent.

1700 m3/capita threshold

IFPRI, 2010

Dryland areas cover 41% of the earth’s surface, and are home to over 1.7 billion people – and the majority of the

world’s poor. About 16% of the population lives in chronic poverty, particularly in marginal rainfed areas.

Predominance of Dryland Areas

Dry Areas (including NV)

• Physical water scarcity

• Rapid natural resource degradation and desertification

• Groundwater depletion

• Drought • Climate change

will make it drier

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1982 1985 1988 1991 1994 1997 2000 2003 2006

m

Decrease of the Souss aquifer level in Morocco

Ecosystem Resilience: Integrated Crop/Rangeland/Livestock Production Systems

Barley Production

Cactus & Fodder Shrubs

By-products Feed Blocks On-farm Feed

Production

Flock management

Natural Pastures Enhancement & Rangeland Management

Successful Technologies

Marginal Land (Badia) Agro-Ecosystem

Water harvesting technologies Micro-catchments mechanized contour laser planting Effective water harvesting Grazing management 40-50% increase in rainwater productivity

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No intervention Micro WH Macro WH

% o

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Evaporation Transpiration



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Soilless Culture Increased

yield per unit of water,

space and energy

Protected Agriculture

Urbanization %

0

20

40

60

80

100

Ethi

opia

Afg

hani

stan

Eritr

ea

Tajik

ista

n

Yem

en

Som

alia

Paki

stan

Kyr

gyzs

tan

Uzb

ekis

tan

Suda

n

Egyp

t

Turk

men

ista

n

Syria

Aze

rbai

jan

Geo

rgia

Kaz

akhs

tan

Mor

occo

Alg

eria

Mau

ritan

ia

Arm

enia

Tuni

sia

Iran

Turk

ey

Cyp

rus

Iraq

Pale

stin

e

Jord

an

UA

E

Liby

a

Leba

non

Saud

i Ara

bia

Kuw

ait

Less than 30% 30-50% 51-70% More than 70%

Urbanization in Countries of Dry Areas

Source: FAO Statistical Yearbook, Vol.1, 2004.

Diagnostic & Base Line Surveys

Basic Research

Applied Research

Adaptive/Strategic Research

Researcher/Extension Agent/Farmer on-Farm Trials

Farmer-Managed On-Farm Trials

Pilot Production-Cum-Demonstration Plots by Farmers; Extension

Commercial

Production Project

IMPACT STUDIES

The Continuum from Basic Research to Technology Transfer

ON-FARM FEEDBAC

K

Adoption Studies

why dryland ecosystems matter -...

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