Repeat photography innorthwestern Yunnan

Northwestern Yunnan (28° N latitude; 99°E longitude) lies in the Hengduan Moun-tains, a physiographical and biologicaltransition between the Tibetan Plateau onthe north and Indo-Malayan lowlands onthe south. The 15 counties comprisingnorthwestern Yunnan cover 69,000 km2

and are dominated by 11 ethnic minoritycultures, including Naxi, Tibetan, Bai,Lisu, and Nu. Basic knowledge about therates and patterns of ecological and landuse change is lacking in this remote area.Until empirical studies are conducted, his-torical landscape photographs provide areadily accessible baseline of visual indica-tors from which to assess past change.Repeating this photography—capturing amodern image that recreates as nearly aspossible conditions of the original scene—can provide a direct assessment of ecologi-cal and land use trends during the lastcentury.

We started by collecting as many oldlandscape photographs as possible. Sourcesinclude published books and magazinearticles, as well as many unpublished pho-tographs in the archives of the NationalGeographic Society (US), Royal Geographi-cal Society (UK), Harvard University, andother institutions in the US and Europe.Of the total set of photographs available,we chose only landscape photographs withenough features to aid in the exact reloca-tion of the original photopoint. Excludedwere portraits of people and close-ups ofvillages and vegetation, because the photo-

point could not be relocated exactly. So far,we have compiled a collection of about1000 historical landscape photographs.These baseline or “original” photos weretaken by Western explorers travelingthrough the area between 1899 and 1949,including botanists, zoologists, geologists,diplomats, geographers, ethnographers,foreign aid workers, religious missionaries,and tourists.

Between April 2001 and June 2005, werelocated 413 of these historical photo-points that were originally occupied by 16different photographers. These repeatedphotographs sample every major ecosys-tem type, 11 counties, and 7 ethnic groups(Figure 1). Although the data set is ratherlarge, areal coverage is still only a smallfraction of northwestern Yunnan. TheNature Conservancy maintains an elec-tronic database with the old image andnew images that capture the originalscene, as well as related text informationon the original photograph, photopointlocation, dominant ethnic groups, and adescription of changes in the visual indi-cators of environmental change.

Conservation implications of thephoto recordThe database continues to grow, but froma preliminary interpretation of the photorecord 6 results emerge as noteworthy interms of biodiversity conservation.

Forest coverOverall, forest cover has changed little innorthwestern Yunnan during the last

Historical Landscape Change inNorthwestern Yunnan, ChinaUsing Repeat Photography to Assess the Perceptions and Realities of Biodiversity Loss

Robert K. Moseley

214

Mountain Research and Development Vol 26 No 3 August 2006: 214–219

Biodiversity conservation programs rely onaccurate knowledge about past rates of eco-logical change and patterns of human use.In remote areas of the world, empirical dataon historical trends rarely exist to informconservation planning. Such is the case inthe mountains of Yunnan, where there aremany perceptions about historical drivers ofenvironmental change, but little direct evi-dence. Since 2001, The Nature Conservan-cy has employed repeat photography todevelop a historical profile for northwesternYunnan. This 100-year profile allows us toassess the true magnitude of threats to bio-

diversity and the long-term contributionsmade by indigenous cultures to biodiversitymaintenance. We found that many assump-tions, often stated as fact, are wrong or donot apply universally. The magnitude anddrivers of forest cover loss, arid shrublanddynamics, crop field expansion, and glacierretreat fall into this group. We also foundthat some threats have been ignored, suchas a rapidly warming climate. The direct evi-dence of landscape change provided byrepeat photographs has a range of conser-vation policy, investment, and managementimplications.

Development

215

century. In nearly all scenes of land-scapes managed by local communities,forest area and tree density within exist-ing stands have remained stable orincreased. The few exceptions to thistrend include areas dominated by the Yiethnic group and stands clear-cut bycommercial logging between the 1970sand 1990s. These findings contradictmost other accounts of forest coverdynamics in China and Yunnan. Furtherresearch on the causes of this relativestability is needed, but preliminarilythere appear to be 3 main causes innorthwestern Yunnan:

1. Wildfire appears to have been wide-spread during the first half of the

20th century, most likely originatingfrom intentional or accidentalhuman sources. Vigorous fire sup-pression during the last 50 years hasallowed some grasslands to reforestnaturally and for savannahs andwoodlands to increase tree cover, insome cases becoming closed-canopyforests.

2. There has been greater crop fieldabandonment in forests than clearingof new areas during the last 100 years(see below, “Agriculture”).

3. The photos clearly show that someforests have been continuously usedby villagers for fuel and constructionmaterial during the last century, yetforest area and tree density have

26°N 26°N

27°N 27°N

28°N 28°N

29°N 29°N

99°E

99°E

100°E

100°E

101°E

101°E

4379

4075

4129

6740

5010

4036

53106246

4595

4285

3657

4023

5596

YulongxueShan

GuangmaoShan

4227

4193

4122

Jinsha(Yangtze)

Jinsz

han

(Yagt

e)

Jinsha(Ya

)ngtze

Jinsha

(Yangtze)

Lao

ncang(M

ekng)

Lancang(M

ekng

o)

Nu

(Salween)

Nu(Salw

nee )Yalong

Litang

Shui

tuo

Nmai Hka

Dulong

Xo

ChengHai

ErHai

MYA N M A R

Y U N N A N

S I CHUAN

T IB ET

DeqinDeqin

GongshanGongshan

FugongFugong

LanpingLanping

ZhongdianZhongdian

YulongYulong

LushuiLushui

YunlongYunlong

JianchuanJianchuan

EryuanEryuan

DaliDali

HeqingHeqing

BinchuanBinchuan

WeixiWeixiNinglangNinglang

Lanping

Ninglang

Deqin

Benzilan

Zhongdian

QiaotouJudian

Gongshan

Weixi

Bingzhongluo

Fugong

Zhiziluo Jianchuan

Lijiang

Yongsheng

Heqing

Jinjiang

Binchuan

Huaping

Yunlong

Eryuan

Dayao

Lushui

Caojian

Dali

Panzhihua

0 50 kmN

County capitalVillageMain roadOther roadNational boundaryProvince boundaryPrefecture boundaryCounty boundaryStudy area

0 100 kmNN 22°N22°N

26°N26°N

100°E100°E 104°E104°EStudy areaStudy area

Y u n n a nY u n n a n

GuizhouGuizhou

SichuanSichuan

TibetTibet

MYAN-MAR

MYAN-MAR

LAOSLAOS VIETNAMVIETNAM

YunnanProvince

CHINA

KunmingKunming

BeijingBeijing

LhasaShanghaiShanghai

FIGURE 1 NorthwesternYunnan. (Map by AndreasBrodbeck)

Robert K. Moseley

Mountain Research and Development Vol 26 No 3 August 2006

216

remained stable or increased in thesestands (Figures 2A and 2B).

A note of caution is called for here.Repeat photography can easily detect

changes in forest cover and density, buttrends in other attributes of forest healthare more difficult to observe. For exam-ple, low-magnitude, selective tree fellingfor local use as fuel and constructionmaterial can cause compositional andstructural changes inside a forest standthat alter biodiversity. This activity is wide-spread across northwestern Yunnan, but isvery hard to detect with repeated land-scape photography. A more intensive sam-pling method will be needed to measureits conservation impact.

Arid shrublandsPhoto comparisons along the Lancang(upper Mekong) and Jinsha (upperYangtze) rivers illustrate that arid shrub-lands have dominated the landscape for atleast a century. These dry environments,characterized by less than 300 mm ofannual precipitation, are caused by local-ized climatic effects, whereby tall moun-tains to the west stop the rain from reach-ing the valley bottoms on the east. Howev-er, many people in southwestern China,including policy makers and governmentofficials, believe that this non-forest zonehas been caused by recent deforestation.Recent popular writing has even blamedthe lack of forestland in the arid canyonbottoms on government logging and localvillagers. These misperceptions have ledto government reforestation programs forland that cannot support trees. The repeatphotos provide direct evidence that this isa misguided investment.

AgricultureEven though village populations havenoticeably increased, clearing of nativevegetation for crop fields has notincreased dramatically during the 20thcentury. Most increases have been small inarea and located adjacent to settlements.In many places, crop fields have beenabandoned and subsequently reverted toshrubland and forest vegetation. It is com-monly stated that there has been consider-able forest clearing during the last 50years because of agricultural expansion.Our research supports the view that, formost areas of northwestern Yunnan, thisthreat to biodiversity has been overstatedand that deforestation due to agricultural

FIGURES 2A AND 2B Mountainside above Chalitong village, Deqin County. Vertical streakson the left side of the images, faint in 1923 and obvious in 2003, are trails used to slidelogs down to the village. Their presence in both images indicates that forests have beenunder continuous use for 80 years, yet cover has remained stable. (Original photograph byJoseph Rock/National Geographic Image Collection, 19 November 1923; modern photographby Robert Moseley/The Nature Conservancy, 24 October 2003)

Development

217

conversion is not just a new phenomenonin the region. It dates back several cen-turies.

Climate change and glaciersThe photos show that all glaciers innorthwestern Yunnan are shrinking, likenearly all glaciers in the world. The lossof snow and ice cover worldwide is con-sidered to be the classic indicator of awarming climate. In northwestern Yun-nan, however, there are misperceptionsas to the cause of rapid glacial retreat. Asurprisingly widespread misperceptionplaces the blame on tourism develop-ment. After a development company builta tram to the edge of an alpine glacier inYulong Snow Mountain Nature Reserve in1997, they were widely criticized for caus-ing the noticeable retreat of this smallglacier. Due to this criticism, they con-tracted the Chinese Academy of Sciencesto study the situation. Many glaciers inour repeat photographs have never expe-rienced any tourism development, yet allhave been declining throughout the lastcentury.

A more local misperception involvesthe retreat of Mingyong Glacier, whichdescends from Khawa Karpo Peak onthe Yunnan–Tibet border in DeqinCounty (Figures 3A and 3B). KhawaKarpo is in the top tier of mountainssacred to all Tibetan Buddhists. Ming-yong Glacier is an important part of thesacred landscape around Khawa Karpoand 2 temples are located along its low-er edge. Having repeatedly observed theterminus on the way to the temples,long-time residents and pilgrims knowthat this glacier is in rapid retreat.Indeed, a local Buddhist monk oncereflected on this retreat and was con-cerned that it may be due to lack ofdevotion by himself and fellow Bud-dhists.

Climate change and alpine meadowsWhile the physical manifestation of awarming climate is easily observed inshrinking glaciers, indicators of ecologicalimpacts are subtler. One of the most ther-mally sensitive and visibly distinct indica-tors is the boundary between woody andherbaceous vegetation in high mountains.

Research has shown that alpine timberlineincreases in elevation and alpine shrub-lands increase in cover as the result of awarming climate.

These vegetation dynamics are readi-ly observed in repeat photographs. Innorthwestern Yunnan, several sets of pho-tos show that these phenomena are inprogress. Shrubs are encroaching intoalpine meadows and timberline isincreasing in elevation, measured at onesite at a rate of about 8.5 m per decade.We know that increasing woody vegeta-

FIGURES 3A AND 3B The sacred MingyongGlacier adjacent to Taizi Temple, DeqinCounty. There has been a decrease in icevolume over the 91 years and bedrock hasbecome exposed in the icefall. (Originalphotograph by Frank Kingdon Ward/RoyalGeographical Society, June 1913; modernphotograph by Robert Moseley/The NatureConservancy, 19 October 2004)

Robert K. Moseley

Mountain Research and Development Vol 26 No 3 August 2006

218

tion in alpine regions of Yunnan willreduce both the high biodiversity natu-rally found in meadows and the liveli-hoods of Tibetans who rely on herba-ceous vegetation for yak butter produc-tion and medicinal plants. This situationmay now be exacerbated by a government

ban on all use of fire as a managementtool. Although this ban was established toprotect forests, it is applied to all ecosys-tems and now prevents Tibetan herdersfrom using this traditional method toreduce shrubs in alpine meadows. Gov-ernment policy needs to recognize varia-tion in ecosystems. A single, universallyapplied policy can conserve some ecosys-tems, but cause the loss of biodiversityand livelihoods in others.

Invasive plant speciesExotic species invading native habitats is aglobal threat to biodiversity and a majorconservation issue in China. One excep-tion to this appears to be northwesternYunnan. The photo comparisons, as wellas field observations and expert opinion,all suggest that invasive plant species arenot a major threat to terrestrial biodiversi-ty here, unlike virtually every other tem-perate region of the world. One hypothe-sis put forward to explain this phenome-non is that the high species, community,and landscape diversity of the area haslimited the ability of non-native species tobecome established and spread.

Conclusions

Repeat photography of northwestern Yun-nan delivers some clear signals for conser-vationists. In particular, comparisons ofphotographs taken between 1899 and2005 do not support many commonassumptions made regarding Yunnan’senvironmental degradation. Causes of gla-cier retreat on the peaks and the presenceof arid shrublands in the canyons havebeen blamed on the wrong sources. Like-wise, we need to reevaluate the relativethreats of climate change, agriculturalexpansion and local wood collection tobiodiversity (Figures 4A and 4B). Notably,the repeat photos show that there hasbeen no simple unidirectional loss of for-est cover associated with human activityduring recent decades. Forest coverchange has been driven by a complex ofbiological, physical, and anthropogenicfactors that had their origins long before1950. More generally, our repeat photog-raphy points out that there needs to be amuch better linkage between conservation

FIGURES 4A AND 4B Hillsides near Lazhidi village, Fugong County. Many crop fields andpastures in 1936 are now forested. (Original photograph by André Guibaut/Annales deGéographie, summer/autumn 1936; modern photograph by Robert Moseley/The NatureConservancy, 4 November 2003)

Development

219

decision making and the scientific under-standing of biodiversity loss. The risk ofmaking bad conservation investments istoo high to ignore this.

Considerations for conservation policy,management, and investment• Historical profiles promote realistic

goal-setting for conservation and devel-opment programs.

• Conservation managers should bethoughtfully skeptical of prevailingassumptions and require data-driventhreat assessments before makinginvestment decisions.

• Historical landscape photography canprovide an inexpensive and readilyaccessible source of baseline data onhistoric conditions for the last century.

• Traditional resource management innorthwestern Yunnan appears to bemore sustainable than previouslythought. Managers need to document

indigenous ecological knowledge andincorporate it into conservation pro-grams as a complement to modern sci-entific knowledge.

• There is a considerable lack of under-standing in Yunnan about the effects ofglobal warming on natural and socialsystems, causing both inappropriateinvestment and spiritual angst. Photocomparisons help demonstrate that gla-cial retreat is a global climate changephenomenon, not a local conservationor faith issue.

• Conservation managers must recognizethat rapid warming is occurring and isaffecting the land and species undertheir jurisdiction. They must adapt theirpractices and policies to anticipate andbe resilient to this inevitable change.

• Observing the past through repeat pho-tography helps establish reliable indica-tors for measuring future conservationimpact.

AUTHOR

Robert K. MoseleyThe Nature Conservancy, 77 Xi Chang Road, Kunming,Yunnan, China 650034 (Current address: 1902 North11th Street, Boise, Idaho 83702, USA).bobmoseley@hotmail.com

Robert Moseley was Director of Conservation Sciencefor The Nature Conservancy’s China Program from 2000to 2005. For the 25 years prior to that he worked on bio-diversity conservation in the mountains of Idaho. Althoughtrained in alpine ecology, he has spent his career as anapplied conservation biologist involved in a wide range ofinterdisciplinary collaborations, including protected areadesign and management, rare plant conservation, high-mountain floristics, primate conservation planning, wet-land and riparian ecology, broad-scale conservationassessments, and, more recently, the implications of cli-mate change and Tibetan sacred landscapes for biodiver-sity conservation.

FURTHER READING

Baker BB, Moseley RK. In press. Advancing treeline andretreating glaciers: Implications for conservation in Yun-nan, China. Arctic, Antarctic, and Alpine Research. Avail-able from Robert K. Moseley.Byers A. 2005. Contemporary human impacts on alpineecosystems in the Sagarmatha (Mt Everest) NationalPark, Khumbu, Nepal. Annals of the Association of Ameri-can Geographers 95:112–140.Ives JD. 2004. Himalayan Perceptions: EnvironmentalChange and the Well-being of Mountain Peoples. NewYork: Routledge.Lassoie JP, Moseley RK, Goldman KE. 2005. Ground-based photomonitoring of ecoregional ecologicalchanges in northwestern Yunnan, China. In: Aguirre-BravoC et al editors. Monitoring Science and Technology Sym-posium: Unifying Knowledge for Sustainability in the West-ern Hemisphere. 2004 September 20–24; Denver, CO.Proceedings RMRS-P-37CD. Fort Collins, CO: US Depart-ment of Agriculture, Forest Service, Rocky MountainResearch Station. CD-ROM. See http://www.fs.fed.us/rm/pubs/rmrs_p037.html for details.Moseley RK, Tang Y. 2006. Vegetation dynamics in thedry valleys of northwestern Yunnan, China, during thelast 150 years: Implications for ecological restoration.Journal of Plant Ecology 30(5):713–722.