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LETTER doi:10.1038/nature13717
A global strategy for road building
William F. Laurance
, Gopalasamy Reuben Clements
, Sean Sloan
, Christine S. O’Connell
, Nathan D. Mueller
, Miriam Goosem
Oscar Venter
, David P. Edwards
, Ben Phalan
, Andrew Balmford
, Rodney Van Der Ree
& Irene Burgues Arrea
The number and extent of roads will expand dramatically this century
Globally, at least 25 million kilometres of new roads are anticipated
by 2050; a 60% increase in the totallength of roads over that in 2010.
Nine-tenths of all road construction is expected to occur in develop-
ing nations
, including many regions that sustain exceptional biodi-
versity and vital ecosystem services. Roads penetrating into wilderness
or frontier areas are a major proximate driver of habitat loss and frag-
mentation, wildfires, overhunting and otherenvironmental degrada-
tion, oftenwith irreversible impacts on ecosystems
. Unfortunately,
much road proliferation is chaotic or poorly planned
, and the rate
of expansion is so great that it oftenoverwhelms the capacity of envi-
ronmental planners and managers
for prioritizing road building. This large-scale zoning plan seeks to
limit the environmental costs of road expansion while maximizing
its benefits for human development, by helping to increase agricul-
tural production, which is an urgent priority given that global food
demand could double by mid-century
. Our analysisidentifies areas
with high environmental values where future road building should
be avoided if possible, areas where strategic road improvements could
promote agricultural development with relatively modest environ-
mental costs, and ‘conflict areas’ whereroad building could have size-
able benefits for agriculture but with serious environmental damage.
Our plan provides a template for proactively zoning and prioritizing
roads during the most explosive era of road expansion in human history.
A multitude of factors is promoting rapid road expansion globally,
includinga quest for valuable resources such astimber, minerals, oiland
arable land, and initiatives to increase regional trade, transportation and
energy infrastructure
. Yet, while new roads can promote social and
economic development
, they also can open a Pandora’s box of envi-
ronmental problems
. This is especially the case in pristine or frontier
regions, wherenew roads often dramaticallyincrease land colonization,
habitat disruption, and overexploitation of wildlife and natural resources
It is broadly understood that the best strategy for maintaining the integ-
rity of wilderness areas is by ‘avoiding the first cut’—keeping them road-
—because deforestation is highly contagious spatially
and because
new roads tend to spawn networks of secondary and tertiary roads that
greatly increase the extent of environmental damage
. Unfortunately,
new roads are now penetrating into many of the world’s last surviving
wildernesses, including the Amazon
, New Guinea
, Siberia
the Congo Basin
However, some roads generate substantial social and economic ben-
efits with only modest environmental costs. Particularly in developing
nations, vast expanses of land havebeen settled buthave low agricultural
productivity because of poor access to fertilizers and modern farming
. In such contexts, new roads—or road improvements
such as paving—could increase access to agricultural supplies and markets,
facilitating production increases and lowering post-harvest crop losses
As such accessible areas tend to sustain more prosperous rural livelihoods,
they may also act as ‘magnets’, attracting colonistsaway from environ-
mentally vulnerable frontier areas, such as the margins of forests
this way, improving transportation in suitable areas could help to con-
centrate and improve agricultural production, raising farm yields
potentially promoting land sparing for nature conservation
Despite the pivotal role that roads have in human land-use, efforts
to plan and zone roads are extremely inadequate. First, although roads
increasingly dominate muchof Earth’s land surface (Fig. 1),many roads
are unmapped, especially in developing nations; in the Brazilian Amazon,
for example, the total length of unofficial or illegal roads is nearly triple
that of official roads
. Second,environmental-impact assessmentsoften
place the burden of proof on road opponents
, who rarely have suf-
ficient information on rare species, biological resources and ecosystem
needed to determine the actual environmental costs of roads.
Third, many road assessments are limited in scope
, focusing only on
the direct effects of road building while ignoring its critical indirect effects,
such as promoting deforestation, fires, poaching and land speculation.
Finally, because there is no strategic, proactive system for zoning roads
globally, road projects must be assessed with little information on their
broader context (see the 2013 report on high-risk road development by
the ConservationStrategy Fund;
default/files/field-file/CSFPolicyBrief_14_english_1.pdf). This increases
the burden on road planners and evaluators,who are being swamped by
the unprecedented pace of contemporary road expansion
For these reasons, we devised a ‘global roadmap’ to identify areas in
which roadsor road improvementsare likely to have major costs or ben-
efits. The map has two components: an environmental-values layer that
estimates the natural importance of ecosystems, and a road-benefits layer
that estimates the potential for increased agricultural production, in part
via new or improved roads. Combining these two layers allows us to
identify areas where roads or road upgrades could have large potential
benefits, areas where road building should be avoided wherever possible,
and conflict areas where their potential costs and benefits are both sizeable.
We created the environmental-values layer (Fig. 2a) by integrating
global data sets on three classes of parameters: biodiversity (number of
threatened terrestrial-vertebrate species, estimated number of plant spe-
cies per ecoregion); key wilderness habitats (G200 terrestrial ecoregions,
important bird areas and endemic bir d areas, biodiversity hotspots, fron-
tier forests, high-biodiversity wilderness areas); and carbon storageand
climate-regulation services ofthe local ecosystem (seeMethods and Sup-
plementary Figs 1–11). Values for each class were equally weighted, rescaled
(range: 0–1) and then averaged to produce the environmental-values
layer. Regions that scored highly on this layer include wet and humid
tropical and subtropical forests, Mediterranean ecosystems, wildlife-rich
savanna woodlands in South America and Africa, many islands, certain
mountain ranges, and some higher-latitude forests, among others.
The road-benefits layer(Fig. 2b) identifies areas where new roads or
road improvements could potentially help to improve agricultural pro-
duction.Like the environmental-values layer, it is a relative index(range:
0–1). In general terms, areas that score highly on this layer have been
largely converted to agriculture (and thus have little native vegetation
remaining), arerelatively low-yielding despite having soils and climates
Centre for Tropical Environmental and Sustainability Science, and College of Marine and Environmental Sciences, James Cook University, Cairns, Queensland 4878, Australia.
Kenyir Research Institute,
Universiti Malaya Terengganu, 21030 Kuala Terengganu, Malaysia.
Institute on the Environment, and Department of Ecology, Evolution, and Behavior, University of Minnesota, Saint Paul, Minnesota
55108, USA.
Center for the Environment, Harvard University, Cambridge, Massachusetts 02138, USA.
Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK.
Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK.
Australian Research Centre for Urban Ecology, and School of Botany, University of Melbourne, Melbourne, Victoria 3010,
Conservation Strategy Fund, 663-2300 Curridabat, San Jose
´, Costa Rica.
11 SEPTEMBER 2014 | VOL 513 | NATURE | 229
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broadly suitable for agriculture, are not so distant from urban markets
that crop-transportation costs would be prohibitive even with new or
improvedroads, and are expected to see large future increases in agricul-
tural production to meet projected food or export demands (see Methods
and Supplementary Figs 12–16 for details of how these data sets were
integrated). All continents have regions that score highly, including parts
of south Asia, east and southeast Asia, West and East Africa, central Eur-
asia, west-central North America, Central America and Mexico, and the
Atlantic region of South America.
We classified each of the environmental-values (Fig. 2a) and road-
benefits (Fig. 2b) layers into deciles and then cross-tabulated them to
generate 100 unique colour combinations (see Supplementary Infor-
mation for details). In this scheme, green-shaded areas are where road
building would have relatively high environmental costs and only modest
potential benefits for agriculture. Red-shaded areas are the opposite, with
high potential to increase agricultural production and lower scores on the
environmental-values axis. Black and dark-shaded areas are ‘conflict
zones’ with high values on both axes, whereas white and light-shaded
areas are lower priorities for both environment and agriculture.
On top of this scheme we overlaid polygons for 177,857 protected areas
(Supplementary Fig. 17) globally, using available data from the World
Database on Protected Areas ( Protected areas
Figure 1
The distribution of major roads globally. Roads are indicated
in black; white areas lack mapped roads. The quality of road maps varies
greatly among nations, with many smaller and unofficial roads remaining
unmapped. We generated this map using data from the integrated gROADS
database (
open-access-v1; accessed 7 June 2014); Center for International Earth Science
Information Network - CIESIN - Columbia University, and Information
Technology Outreach Services - ITOS - University of Georgia. 2013. Global
Roads Open Access Data Set, Version 1 (gROADSv1). Palisades, NY: NASA
Socioeconomic Data and Applications Center (SEDAC).
High : 1
Low : 0
High : 1
Low : 0
Figure 2
The environmental-values and road-benefits layers. a,b, The
environmental-values layer (a) integrates data on terrestrial biodiversity, key
habitats, wilderness, and environmental services. The road-benefits layer
(b) shows areas broadly suitable for agricultural intensification, where new
roads or road improvements could potentially promote increased production.
See Supplementary Information for data sources.
230 | NATURE | VOL 513 | 11 SEPTEMBER 2014
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were zoned fully green because we judged that they should be free of
new roads wherever possible, given that roads can facilitate illegal acti-
vities such as poaching, encroachment, and vehicle-related road-kill of
that are contrary to the goals of protected-area management
The resulting global roadmap (Fig. 3)attempts to portray key relative
risks and rewards of road building for each 1-km
pixel on Earth’s land
surface. In broad terms, our map illustrates the enormous potential for
environmental loss and degradation as a result of contemporary road
expansion (Table 1 and Supplementary Fig. 18). Roads are currently pro-
liferating or planned in manyareas categorized as having high environ-
mental values but only modest agricultural potential, such as the Amazon
Basin, parts of the Asia-Pacific region, and higher-latitude forests in the
Northern Hemisphere.
The roadmap also reveals extensive conflict areas (Fig. 3), where environ-
mentaland agricultural values are both high, particularly inSub-Saharan
Africa,Madagascar, Central America, the Mediterranean, southeast and
south-central Asia, the Andes, and theAtlantic regionof South America.
Conflict zones often occur in regions withrapid population growth,high
speciesendemism, or both.In total, 1.97 billionhectares (15.3%of global
land area) fall into conflict areas (Table 1). Land-use pressures in such
regions are mounting rapidly; it has been estimated that, unless current
agricultural yields markedly improve, approximately 1 billion hectares
of additional farming and grazing land will be needed by 2050 to meet
projected food demands
, with extensive additional lands converted for
production of biofuels
However, our road-planning scheme also suggests that many areas
could be targeted for agricultural production increases with relatively
modest environmental costs.Such areas include expanses of the Indian
subcontinent, centralEurasia, the Irano-Anatolian region, and African
Sahel, amongothers (Fig. 3). In total, 1.46billion hectares of land(11.4%
of global land area) is zoned red (Table 1), suggesting that there is con-
siderable potential on every continent to increase agricultural produc-
tion, by raising yields on existing farming and grazing land.
Although improved roads or other transportation can facilitate agricul-
tural yield increases
, additional measures—such as investments in
improved farming methods, fertilizers and, where appropriate, irrigation—
will also be essential. A particular challenge will be devising strategies
to help developing nations with exceptional environmental values, such
as Madagascar and Indonesia (Fig. 2a), to meet pressing economic and
food-production needs while limiting the environmental costs of rapid
road development. For such nations, international payments forecosys-
tem services, ecotourism, and sustainable harvesting of native production
forests could potentially help to balance economic and environmental
. A further priority when planning road and agricultural invest-
ments is to considerhow factors such as inter-annual weather variability
or projected future climate change could impact on crop yields
The global roadmap we created underscores the potential benefits and
need for strategic road planning, but actual road planning will be under-
taken at smaller national or regional scales. For this, we created more
detailed maps that show finer-scale features (for example, Extended Data
Fig. 1). These maps and their components are freely available (http:// andcan be combined with additional data, such as
more detailed information on topography, soils, existing croplands and
local road networks, to facilitate road planning.
Integrating local information is important because the drivers and
environmental impacts of road construction will vary in different con-
texts. For example, in arable, largely road-freeareas of East Africa (Fig. 4a),
new roads driven by a burgeoning mining boom
could provoke major
land-use changes andhabitat loss. Yetexpanding roads from timber and
miningoperations could also have large impacts in Siberia (Fig.4b), even
No data
Environmental values
Agricultural potential
Figure 3
A global roadmap. Shown are priority road-free areas (green
shades), priority agricultural areas (red shades), conflict areas (dark shades),
and lower-priority areas(light shades). Values of the environmental-values and
road-benefits layers are each divided into deciles, yielding 100 unique colour
combinations. See Supplementary Information for details and data sources.
Table 1
Percentages of seven geographical regions that fall into four broad categories on the global roadmap
Zone Africa Asia Australia Europe North and Central America South America Oceania Global
Conserve 29.03 45.69 34.21 26.44 47.39 66.28 95.29 42.96
Agriculture 7.93 12.44 3.63 32.92 11.35 6.83 0.23 11.40
Conflict 24.75 14.87 7.01 9.10 8.70 15.74 0.58 15.34
Low-tension 38.30 27.00 55.15 31.54 32.55 11.14 3.89 30.30
Total area 29,805 44,174 7,693 9,670 23,395 17,662 412 132,811
Data on the total areas of each region are given in km
. ‘Conserve’ zones are where road building would have relatively high environmental costs (above-median environmental values; Fig. 2a) and modest
potential agricultural benefits (below-median road-benefits values; Fig. 2b). ‘Agriculture’ zones have the opposite attributes (above-median road-benefits values and below-median environmental values).
‘Conflict’ zones have both above-median environmental values and above-median road-benefits values, whereas ‘low-tension’ zones are lower priorities for both environment and agriculture (with below-median
environmental and road-benefits values). See Supplementary Fig. 18 for a map of these zones.
11 SEPTEMBER 2014 | VOL 513 | NATURE | 231
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though agricultural potential is limited, by promoting forest fires and
. In general, we expect road impacts to be lowest in unproduc-
tive, arid regions, moderate in carbon-rich ecosystems such as higher-
latitude forests, and most damaging in species- and carbon-rich ecosystems
such as tropical forests, particularly where few roads currently exist.
We see our global road-mapping scheme as a working model—an
important first step towards strategic road planning to reduce environ-
mental damage—that can be downscaled and tailored for particularcir-
cumstances. We believe such proactive planning should be a central
element of any discussion about road expansion and associated land-
use zoning
. Given that the total length of new roads anticipated by
would encircle the Earth more than 600 times, there is
little time to lose.
Online Content Methods, along with any additional Extended Data display items
and SourceData, are available in theonline version of the paper;references unique
to these sections appear only in the online paper.
Received 19 May; accepted 28 July 2014.
Published online 27 August 2014.
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Acknowledgements We thank T. Brooks, S. Butchart, J. Geldmann, S. Goosem,
C. Mendenhall,N. Pares, S. Pimm, U. Srinivasan,N. Velho, and two anonymous referees
for comments and feedback. The Australian Research Council provided support.
Author Contributions W.F.L. and A.B. initially conceived the study, and W.F.L.
coordinated its design, analysis, and manuscript preparation. G.R.C. and S.S.
conducted the spatial analyses; C.S.O., N.D.M., O.V., G.R.C., S.S. and B.P. generated or
collated key datasets; and M.G., D.P.E., R.V.D.R. and I.B.A. provided ideas and critical
Author Information Reprints and permissions information is available at The authors declare no competing financial interests.
Readers are welcome to comment on theonline version of the paper. Correspondence
and requests for materials should be addressed to W.F.L. (
Figure 4
Mapped roads overlaid onto the roads-benefits layer. a,b,In
eastern Africa (a) and Siberia (b), roads are rapidly expanding into relatively
road-free areas, but for different reasons. Narrow black lines indicate mapped
roads. In both regions, areas with darker-red colours have greater agricultural
potential than those with lighter colours. See Supplementary Information for
data sources.
232 | NATURE | VOL 513 | 11 SEPTEMBER 2014
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We used ArcGIS 10.1 and IDRISI Selva to integrate spatial data relevant to our
global roadmap. Analyses were conducted using Goode’s homolosine equal-area
projection and a 1-km
pixel size, yielding ,132.8 million pixels for Earth’s ter-
restrial surface (excluding Antarctica). Larger freshwater bodies (.50 km
) were
removed before analysisbut land areas under ice or permafrost were not excluded.
A small fraction (2.21%)of all pixels lacked data (mostly in Greenland) and so were
excluded from the analysis.
We created the environmental-values layer (Fig. 2a) by integrating global data
sets on biodiversity (numberof threatened terrestrial-vertebrate species,estimated
number of plant species per ecoregion); key wilderness habitats (G200 terrestrial
ecoregions, important bird areas and endemic bird areas, biodiversity hotspots,
frontier forests, high-biodiversity wilderness areas); andcarbon storage and climate-
regulation services of the local ecosystem (Supplementary Figs 1–11). Areas that scored
highly on the road-benefits layer (Fig. 2b) were defined by having: a high propor-
tion of land already under farming or grazing; soils and climates that are broadly
suitable for agriculture; large agricultural yield gaps; large projected increases i nf uture
agricultural production; and the potential to access urban markets with improved
transportation (Supplementary Figs 12–16). The globaldata sets that comprise the
environmental-values and road-benefits layers, and the methods by which they
were integrated, are described in detail in the Supplementary Information.
Macmillan Publishers Limited. All rights reserved
Extended Data Figure 1
Roadmaps for northern South America and
Sub-Saharan Africa. Magnified images such as these could be integrated
with local-scale data to facilitate actual road planning. Values of the
environmental-values and road-benefits layers are each divided into deciles,
yielding 100 unique colour combinations. See Supplementary Information for
data sources.
Macmillan Publishers Limited. All rights reserved
Corrigendum: A global strategy for
road building
William F. Laurance, Gopalasamy Reuben Clements,
Sean Sloan, Christine S. O’Connell, Nathan D. Mueller,
Miriam Goosem, Oscar Venter, David P. Edwards, Ben Phalan,
Andrew Balmford, Rodney Van Der Ree & Irene Burgues Arrea
Nature 513, 229–232 (2014); doi:10.1038/nature13717
In this Letter, as a result of an inadvertent spreadsheet error, four values
presented in Table 1 were slightly inflated. These relate to the propor-
tions of Earth’s total land surface located within the ‘conserve’, ‘agri-
culture’, ‘conflict’ and ‘low-tension’ zones. The correct percentage values
for these four zones under the ‘global’ heading are 42.96, 11.40, 15.34
and 30.30, respectively. Two of these values (the global percentages for
conflict and agriculture zones) were also mentioned in the main text.
We apologise for these errors, which have now been corrected in the
online versions of the Letter, and do not affect the interpretation of our
Macmillan Publishers Limited. All rights reserved
... Over time public transport has become more expensive to provide and increasingly unprofitable in some countries, particularly in Europe [67]. However, there is potential to tackle problems related to accessibility and mobility [67,69] by introducing measures to encourage a modal shift to public transport that optimises the environmental, social, and cost benefits of use [70]. By encouraging public transport use that supports the needs of the individual, for example through the provision of flexible and demand responsive forms of transport [71], coupled with the integration of alternative fuels such as electric and hydrogen, it is arguable that greater decarbonisation, energy security and urban air quality improvements could occur [72]. ...
... With ICEVs being phased out across the world and the ever-growing climate change concerns, technological improvements and cost reductions, there has been a growth in the integration of low carbon alternatives including BEVs [68]. However, there is a growing consensus that this technological transition will not be sufficient or fast enough to transform the transport system [69,70]. Even with the technical difficulties being mostly resolved for BEVs, and policy incentives introduced, the target penetration in most countries will not been achieved. ...
... Although HBs are still a relatively new technology, they have been introduced in Asia (i.e. China [70], Korea [71], Taiwan [72]), Europe (i.e. Czech Republic [73], Denmark [68], Netherlands [74], Romania [75], the UK [14] etc.), North America (i.e. the USA [76] etc.) and South America (i.e. ...
... As well as producing pollution, transport infrastructure has the potential to fragment ecosystems, including the unique and diverse ecosystems of the Tropics. Roads and railways can have immediate as well as long-term impacts on tropical environments (Laurance et al., 2014), with new roads being a particular concern for pristine tropical forests, due to their direct implication in land colonisation, habitat disruption and the overexploitation of wildlife and natural resources (Laurance et al., 2014). ...
... As well as producing pollution, transport infrastructure has the potential to fragment ecosystems, including the unique and diverse ecosystems of the Tropics. Roads and railways can have immediate as well as long-term impacts on tropical environments (Laurance et al., 2014), with new roads being a particular concern for pristine tropical forests, due to their direct implication in land colonisation, habitat disruption and the overexploitation of wildlife and natural resources (Laurance et al., 2014). ...
... The negative impacts of roads on animal populations are well-known. Studies have shown that traffic can have profound impacts on the survival of vulnerable species through the modification of habitats and reduced migration survival (Jaarsma, 1997;Forman & Alexander, 1998;Fahrig, 2003;Laurance et al., 2014). These effects include air, noise and chemical pollution, the barrier effect (Forman & Alexander, 1998;Laurance et al., 2009), and direct impact with vehicles. ...
Full-text available
The construction and operation of linear infrastructure has major impacts on biodiversity through loss of habitat, increased mortality and loss of connectivity. In particular, minimising the impact of roads which pass through ecologically sensitive areas on surrounding species at the construction and operational phases is critical for conservation. However, potential impacts are rarely known perfectly at the construction phase and early in the operational phase. To address this problem, a company could build flexibility into road operation so that it can respond rapidly to future ecological impacts if necessary. In this paper we analyse the value of this flexibility using stochastic dynamic programming and use the results to guide a global search algorithm to find high value roads in the region. We consider flexibility in terms of the proportion of traffic volume routed along the road, with the remainder passing along an existing higher-cost, lower-impact road. We applied this to an example scenario where a road must be routed through a region with a vulnerable species present. By incorporating flexibility, the proposed model was able to find a road that met a desired ending population of animals and was more valuable than roads found under existing design alternatives.
... Market proximity has played a central role in shaping theories about terrestrial land use change, 21,23,25 agriculture, 20,31 and conservation. 63 For example, land use change theories cover issues such as how market accessibility (through road networks and market connectivity) influences land use through expansion (e.g., how unconverted ''wildland'' or ''native'' cover is converted Table 1. Main rationale and hypotheses explaining the expected relationships between the four reef fish metrics used in our study and fishing pressure ...
Effective solutions to the ongoing “coral reef crisis” will remain limited until the underlying drivers of coral reef degradation are better understood. Here, we conduct a global-scale study of how four key metrics of ecosystem states and processes on coral reefs (top predator presence, reef fish biomass, trait diversity, and parrotfish scraping potential) are explained by 11 indicators based on key human-environment theories from the social sciences. Our global analysis of >1,500 reefs reveals three key findings. First, the proximity of the nearest market has the strongest and most consistent relationships with these ecosystem metrics. This finding is in keeping with a body of terrestrial research on how market accessibility shapes agricultural practices, but the integration of these concepts in marine systems is nascent. Second, our global study shows that resource conditions tend to display a n-shaped relationship with socioeconomic development. Specifically, the probabilities of encountering a top predator, fish biomass, and fish trait diversity were highest where human development was moderate but lower where development was either high or low. This finding contrasts with previous regional-scale research demonstrating an environmental Kuznets curve hypothesis (which predicts a U-shaped relationship between socioeconomic development and resource conditions). Third, together, our ecosystem metrics are best explained by the integration of different human-environment theories. Our best model includes the interactions between indicators from different theoretical perspectives, revealing how marine reserves can have different outcomes depending on how far they are from markets and human settlements, as well as the size of the surrounding human population.
... Globally, vehicle numbers are predicted to be as high as 2.8 billion by 2050, with an anticipated increase in road length of at least 25 million km. 1,2 The pollution and significant ecological effect associated with this vast and growing infrastructure extends outwards even further into the adjacent landscape in an area described as the "roadeffect zone". 3 The reach of this pollution is significant in the UK, with only 6% of land escaping its impact and 25% of land being within 80 m of a road. ...
The pollution of aqueous environments by metals has continued to increase due to anthropogenic activities such as mining, waste disposal, industrial activities and the use of motor vehicles. Globally, vehicle...
... New strategies for best management practices for potato pests and diseases in Ecuador will need to address purple top and the risk of zebra chip, including uncertainty about causal agents. In considering how to bring about the greatest project benefits, multiple outcomes may be important, and they may include a combination of benefits and environmental costs of management (Laurance et al. 2014), pesticide effects on nontarget species in disease management, or conservation management focusing on both biodiversity hotspots and locations with keystone species (Smith et al. 2007). Our examples addressed management performance mapping with performance defined in terms of the mean performance observed. ...
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Policymakers and donors often need to identify the locations where technologies are most likely to have important effects, to increase the benefits from agricultural development or extension efforts. Higher quality information may help to target the high-benefit locations, but often actions are needed with limited information. The value of information (VOI) in this context is formalized by evaluating the results of decision making guided by a set of specific information compared to the results of acting without considering that information. We present a framework for management performance mapping that includes evaluating the VOI for decision making about geographic priorities in regional intervention strategies, in case studies of Andean and Kenyan potato seed systems. We illustrate use of recursive partitioning, XGBoost, and Bayesian network models to characterize the relationships among seed health and yield responses and environmental and management predictors used in studies of seed degeneration. These analyses address the expected performance of an intervention based on geographic predictor variables. In the Andean example, positive selection of seed from asymptomatic plants was more effective at high altitudes in Ecuador. In the Kenyan example, there was the potential to target locations with higher technology adoption rates and with higher potato cropland connectivity, i.e., a likely more important role in regional epidemics. Targeting training to high management performance areas would often provide more benefits than would random selection of target areas. We illustrate how assessing the VOI can contribute to targeted development programs and support a culture of continuous improvement for interventions.
... Analysis of the physical infrastructure required for transport and buildings, highlighted that if per capita levels of infrastructure in Western countries was constructed globally, using current technologies, it would require using between 35 and 60% of the remaining carbon budget until 2050 to build a global infrastructure to keep average global temperature is to remain below 2°C [69]. Furthermore, analysis has highlighted that at least 25 million kilometres of new roads are anticipated by 2050, which is the equivalent of a 60% increase in total road length in relation to 2010 levels [70]. Therefore, future emission projections from the transport sector should consider the 'induced demand' from the infrastructure and the emissions from the construction of the infrastructure itself [66]. ...
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Although it remains clear that low carbon public transport will produce less emissions than conventionally fuelled alternatives, and much less when compared to personal vehicles per person per kilometre travelled, encouraging the use of public transport has multiple barriers that need to be overcome to increase widespread use. This includes a shift in travel behaviour for consumers in terms of public acceptance of new low carbon public transport, including encouraging public transport use at younger age so that individuals continue to use public transport as they get older. The main barrier remains the cost of the technology itself as well as the additional infrastructure when integrating low emission public transport. As technology advances it is expected that electric and hydrogen public transport costs will decrease, however hydrogen technology is still relatively new making this more challenging. Since travellers are cost-sensitive fares it is important that public transport remains competitive with personal vehicles. Furthermore, the practicalities of integrating new technologies need to be considered. For example, the introduction of electric and hydrogen in public transport will require additional infrastructure for charging which will have a geospatial impact on natural capital and ecosystem services. This is because electric transport will need to be charged more frequently than hydrogen transport due to the range of the vehicles. Furthermore, electrification of public transport will result in additional challenges for power generation and infrastructure development which will need to be addressed for widescale uptake. Therefore, electric charging infrastructure is more likely to be situated within city centres compared to hydrogen transport which can be situated in rural areas.
... We are not aware of any studies that have intersected ecological value with risk of loss for private wildlands in the US at management-relevant spatial scales (but see Theobald 2003, Withey et al. 2012. Similar applications globally include overlaying human pressure on biodiversity intactness (Newbold et al. 2016), risk of deforestation on measures of species endangerment (Tracewski et al. 2016), projected roading on various biodiversity measures (Laurance et al. 2014), and deforestation risk on potential climate refugia (Tabor et al. 2018). ...
Natural habitats on private lands are potentially important components of national biodiversity conservation strategies, yet they are being rapidly lost to development. Conservation easements and other means of protecting these habitats have expanded in use and will be most effective if they target private lands of highest biodiversity value and risk of loss. We developed a Biodiversity Conservation Priority Index (BCPI) based on ecological value and risk of habitat loss for remaining areas of natural vegetation cover (NVC) in the northwestern U.S and addressed two questions: (1) Which remaining NVC on private lands is the highest priority for biodiversity conservation based on ecological value and risk of development?; and (2) Are conservation easements in NVC placed preferentially in locations of high biodiversity conservation priority? Drawing on the concept of ecological integrity, we integrated five metrics of ecological structure, function, and composition to quantify ecological value of NVC. These included net primary productivity, species richness, ecosystem type representation, imperiled species range rarity, and connectivity among ‘Greater Wildland Ecosystems’. Risk of habitat loss was derived from analysis of biophysical and sociodemographic predictors of NVC loss. Ecological value and risk of loss were combined into the BCPI. We then analyzed spatial patterns of BCPI to identify the NVC highest in biodiversity conservation priority and examined the relationship between BCPI and conservation easement status. We found that BCPI varied spatially across the study area and was highest in western and southern portions of the study area. High BCPI was associated with suburban and rural development, roads, urban proximity, valley bottom landforms, and low intensity of current development. Existing conservation easements were distributed more towards lower BCPI values than unprotected NVC at both the study area and region scales. The BCPI can be used to better inform land use decision making at local, regional, and potentially national scales in order to better achieve biodiversity goals.
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Protected areas have numerous roles (such as biodiversity preservation, the development of scientific research and the sustainable use of natural resources), but they are under threat from political and economic forces. The 837 000-ha Serra do Divisor National Park (SDNP) in the south-western Brazilian Amazon combines the conservation of natural resources and the maintenance of the productive activities of c . 400 resident families. The Brazilian and Peruvian governments have proposed a road linking Acre (Brazil) to Ucayali (Peru) that would bisect the SDNP. Another threat to the SDNP is a bill proposing its downgrading to an ‘environmental protection area’. This study aims to map the land cover of the SDNP and its surroundings from 1988 to 2018 and to analyse the dynamics of land-use change. Analysis of Landsat satellite images with supervised classification using the MaxVer algorithm show that, during the 30-year period, pasture showed the highest absolute land-cover gain, with 1986 ha in the interior and 7661 ha along the periphery of the SDNP. Only 1% of the park’s primary forest was lost by 2018, but the proposed road and potential downgrading may result in accelerated deforestation and forest degradation in the near future.
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A debate has emerged over the potential socio-ecological drivers of wildlife-origin zoonotic disease outbreaks and emerging infectious disease (EID) events. This Review explores the extent to which the incidence of wildlife-origin infectious disease outbreaks, which are likely to include devastating pandemics like HIV/AIDS and COVID-19, may be linked to excessive and increasing rates of tropical deforestation for agricultural food production and wild meat hunting and trade, which are further related to contemporary ecological crises such as global warming and mass species extinction. Here we explore a set of precautionary responses to wildlife-origin zoonosis threat, including: (a) limiting human encroachment into tropical wildlands by promoting a global transition to diets low in livestock source foods; (b) containing tropical wild meat hunting and trade by curbing urban wild meat demand, while securing access for indigenous people and local communities in remote subsistence areas; and (c) improving biosecurity and other strategies to break zoonosis transmission pathways at the wildlife-human interface and along animal source food supply chains.
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The number and extent of roads will expand dramatically this century. Globally, at least 25 million kilometres of new roads are anticipated by 2050; a 60% increase in the total length of roads over that in 2010. Nine-tenths of all road construction is expected to occur in developing nations, including many regions that sustain exceptional biodiversity and vital ecosystem services. Roads penetrating into wilderness or frontier areas are a major proximate driver of habitat loss and fragmentation, wildfires, overhunting and other environmental degradation, often with irreversible impacts on ecosystems. Unfortunately, much road proliferation is chaotic or poorly planned, and the rate of expansion is so great that it often overwhelms the capacity of environmental planners and managers. Here we present a global scheme for prioritizing road building. This large-scale zoning plan seeks to limit the environmental costs of road expansion while maximizing its benefits for human development, by helping to increase agricultural production, which is an urgent priority given that global food demand could double by mid-century. Our analysis identifies areas with high environmental values where future road building should be avoided if possible, areas where strategic road improvements could promote agricultural development with relatively modest environmental costs, and 'conflict areas' where road building could have sizeable benefits for agriculture but with serious environmental damage. Our plan provides a template for proactively zoning and prioritizing roads during the most explosive era of road expansion in human history.
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Road construction is now common through wilderness and protected areas in tropical and subtropical countries with adverse consequences for their high native biodiversity. Here, we summarize the scope of the problem and advance specific compromise solutions that reconcile development with conservation.
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Feeding a growing global population in a changing climate presents a significant challenge to society. The projected yields of crops under a range of agricultural and climatic scenarios are needed to assess food security prospects. Previous meta-analyses have summarized climate change impacts and adaptive potential as a function of temperature, but have not examined uncertainty, the timing of impacts, or the quantitative effectiveness of adaptation. Here we develop a new data set of more than 1,700 published simulations to evaluate yield impacts of climate change and adaptation. Without adaptation, losses in aggregate production are expected for wheat, rice and maize in both temperate and tropical regions by 2 °C of local warming. Crop-level adaptations increase simulated yields by an average of 7–15%, with adaptations more effective for wheat and rice than maize. Yield losses are greater in magnitude for the second half of the century than for the first. Consensus on yield decreases in the second half of the century is stronger in tropical than temperate regions, yet even moderate warming may reduce temperate crop yields in many locations. Although less is known about interannual variability than mean yields, the available data indicate that increases in yield variability are likely.
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Africa is on the verge of a mining boom. We review the environmental threats from African mining development, including habitat alteration, infrastructure expansion, human migration, bushmeat hunting, corruption, and weak governance. We illustrate these threats in Central Africa, which contains the vast Congo rainforest, and show that more than a quarter of 4,151 recorded mineral occurrences are concentrated in three regions of biological endemism—the Cameroon-Gabon Lowlands, Eastern DRC Lowlands, and Albertine Rift Mountains—and that most of these sites are currently unprotected. Threats are not uniform spatially, and much of the Congo Basin is devoid of mineral occurrences and may be spared from direct mining impacts. Some of the environmental impacts of African mining development could potentially be offset: mining set-asides could protect some wildlife habitats, whereas improving transportation networks could increase crop yields and spare land for conservation. Research and policy measures are needed to (1) understand the synergies between mining and other development activities, (2) improve environmental impact assessments, (3) devise mitigation and offsetting mechanisms, and (4) identify market choke points where lobbying can improve environmental practice. Without careful management, rapid mining expansion and its associated secondary effects will have severe impacts on African environments and biodiversity.
A noteworthy feature of international environmental discourse since the late-1980s has been the shift toward anticipatory policies. Precaution is the leading policy approach that has emerged to guide environmental decision-makers confronted with inadequate information. The "precautionary principle" has found expression in Australia in the 1992 Intergovernmental Agreement on the Environment, various Commonwealth environmental management strategies and a number of pieces of Commonwealth and State legislation. It also has been accepted tentatively by the courts as a factor which should be taken into account in appropriate circumstances. However, existing Australian environmental management approaches fail to advance precaution in a substantive manner. Most hope for the advancement of precaution has rested on its potential to be a mandatory consideration by ministerial authorities when exercising planning powers. However, courts have cast doubt on the legal status of the principle because of the typically weak formulations of it in legislation and policy documents. In this article, a method is suggested by which the principle could be integrated systematically in environmental planning so that it could be given effect in environmental management practice. The writer proposes that environmental impact assessment (EIA) Australia's foremost environmental protection regime should be modified to give effect to the precautionary principle. A three-step method by which this could be achieved is presented. First, the EIA trigger of environmental 'significance' must be broadened; second, uncertainties must be assessed; and third, environmental uncertainty must have greater influence in decision-making.
Increasing agricultural productivity to 'close yield gaps' creates both perils and possibilities for biodiversity conservation. Yield increases often have negative impacts on species within farmland, but at the same time could potentially make it more feasible to minimize further cropland expansion into natural habitats. We combine global data on yield gaps, projected future production of maize, rice and wheat, the distributions of birds and their estimated sensitivity to changes in crop yields to map where it might be most beneficial for bird conservation to close yield gaps as part of a land-sparing strategy, and where doing so might be most damaging. Closing yield gaps to attainable levels to meet projected demand in 2050 could potentially help spare an area equivalent to that of the Indian subcontinent. Increasing yields this much on existing farmland would inevitably reduce its biodiversity, and therefore we advocate efforts both to constrain further increases in global food demand, and to identify the least harmful ways of increasing yields. The land-sparing potential of closing yield gaps will not be realized without specific mechanisms to link yield increases to habitat protection (and restoration), and therefore we suggest that conservationists, farmers, crop scientists and policy-makers collaborate to explore promising mechanisms.