data?
Improving?the?use?of?information?from?museum?specimens:?Us?
ing?Google?Earth??to?georeference?Guiana?Shield?specimens?in?
the?US?National?Herbarium?
Eduardo?Garcia?Milagros?and?Vicki?A.?Funk??
US?National?Herbarium,?Department?of?Botany,?National?Museum?of?Natural?History,?Smith?
sonian?Institution,?Washington?DC,?20013?7012?USA?
e?mail:?eduadogarmi@gmail.com;?http://botany.si.edu/bdg/index.html??
Introduction?
The?specimen?collections?housed?in?museums?and?
herbaria?are?a?permanent?record?of?a?species?at?a?
given? location?on?a?specific?date.?The? locality?of?a?
collection? is? stored? as? text? on? a? specimen? label.?
Georeferencing? is?the?process?of?converting?these?
locality? descriptions? into? latitude/longitude? coor?
dinates?which?can?be?easily?analyzed?with?GIS?ap?
plications.? These? species?occurrence? data,? to?
gether? with? environmental? variables? are? often?
used? in? various? modeling? methods,? i.e.,? to? plot?
existing?data?and?predict? the?geographic?distribu?
tion?of?species? (e.g.,?Elith?et?al.?2006).?These?pre?
dictive? distribution?models? are? becoming? an? im?
portant?tool?in?analytical?biology,?with?applications?
in? conservation? and? reserve? planning,? ecology,?
evolution,? epidemiology,? invasive?species? man?
agement? and? other? fields? (Phillips? et? al.? 2005);?
however,?they?depend?on?accurate?coordinates.?
Studies? show? that? the? data? stored? in? the? collec?
tions? are? often? geographically,? temporally,? and?
taxonomically?biased?(Funk?et?al.?1999,?ter?Steege?
et?al.?2000,?Funk?and?Richardson?2002,?Reddy?and?
Davalos? 2003).? Although? these? studies? suggest?
that? collecting?more?data? is?necessary,? the? infor?
mation?behind?these?collections?is?of?a?high?value.?
Gathering? such? data? in? databases? and? georefer?
encing?them?is?a?time?consuming?and?underappre?
ciated? task.? However,? once? avaliable? they? are?
used,? for? instance,? in? establishing? priorities? for?
future?expeditionary?research?and?thus?filling?gaps?
in?the?data?(Funk?et?al.?2005)?and?in?regional?con?
servation? planning? (Ferrier? 2002,? Chefaoui? et? al.?
2005).?
? Recently? there?has?been?an? increase? in? the?
availability? of? collections? data? (GBIF,? TROPICOS,?
etc.)?and?an?important?consideration?is?how??good??
or? reliable? they? are.? Estimates? of? quality? have?
been?defined?as??fitness?for?use??(Chrisman?1983)?
or? ?fitness? for? potential? use?? (English? 1999)? and?
Chapman?(2005)?describes?how?many?factors?may?
affect? the? quality? of? the? data.? In? terms? of? geo?
graphic? position? of? location,? precision? and? accu?
racy? are? of? concern? and? geographic? data? always?
resources?ISSN?1948?6596?
Abstract.?Data?found?on?labels?of?museum?collections?have?been?useful?in?a?variety?of?biodiversity?studies.??
However,?the?georeferenced?data?available?are?often?hampered?by?poor? interpretation?of? label? informa?
tion?and?as?a?result?are?not?as?accurate,?and? therefore?useful,?as? they?might?be.? ?We?have?used?Google?
Earth??as?a?geographic?information?system?to?improve?the?georeferencing?of?the?data.?Its?user?interface?
allowed?us? to?make?use?of?all? the? label? information?and? to? represent? the? coordinates?more?accurately,?
thus?producing?a?better?quality?and?more?reliable?dataset?to?be?used?in?our?studies.??The?quality,?defined?
as??fitness?for?use?,?of?the?species?occurrence?data?generated,?which? is?mostly?affected?by?the?values?of?
accuracy? and? uncertainty? associated? to? the? coordinates,? shows? that? uncertainly? can? be? reduced.? ? This?
method?also?allows?us?to?show?the?power?of?examining?georeferenced?data?from?the?stand?point?of? ?all?
collections?from?an?expedition??rather?than??all?collections?from?a?single?area.??Type?specimens?housed?at?
U.S.?National?Herbarium?from?the?Guiana?Shield?were?used?in?this?work.?
?
Keywords.?museum?collections,?georeferencing,?data?quality,?Google?Earth,?type?specimen?
 71?frontiers?of?biogeography?2.3,?2010?????2010?the?authors;?journal?compilation???2010?The?International?Biogeography?Society?
have?an?uncertainty?value?associated?with?them.?
One? goal? of? our? research? is? to? understand? plant?
distributions? across? the?Guiana? Shield? (Biological?
Diversity?of? the?Guiana? Shield?Program,?BDG).? In?
order? to?do? this?we?embarked?on? this?project? to?
apply? the? ?principles? of? the? best? georeferencing?
practices?? (Chapman? and? Wieczorek? 2006)? and?
investigate?the?use?of?Google?Earth??as?a?GIS?ap?
plication? for? georeferencing? and? determine? if? its?
features? could? help? improve? the? quality? of? the?
data.?The?full?scope?of?the?project?involves?check?
ing? the? locations?and?uploading? the?data? from?all?
of? the? collections? at?US?National?Herbarium? (US)?
beginning?with? those?made?by? the?BDG? (see?pro?
gress? at? http://botany.si.edu/bdg/
expeditions.html).?However,?the?sample?data?used?
here?are?from?the?type?collection?of?the?US?which?
are? important? but? provide? the? biggest? challenge?
because?of?the?lack?of?information.??
?
Georeferencing? type? specimens? from? the?
Guiana?Shield?
All?known?species?on?earth?have?an?official?name.?
Typically?that?name?consists?of?a?genus,?a?specific?
epithet,? and? the? name? of? the? person(s)?who? de?
scribed?it.?Usually?each?name?is?tied?to?a?specimen?
that? is? housed? in? a? recognized? collection.? These?
specimens? are? called? ?types?.? All? type? specimens?
from?the?Guiana?Shield?that?are?housed?at?US?(ca.?
3400?specimens)?were?used?in?this?work.?
? When? the?US? type? specimen?database?was?
downloaded,?it?became?clear?that?locality?informa?
tion? varied? from? just? country? information?on? the?
old? collections? to? precise? GPS? latitude/longitude?
coordinates?on? the?most? recent.?Over? time? some?
older?records?had?coordinates?added.?An?examina?
tion?of?these?data?showed?that?during?the?process?
of? entering? them? into? the? database,? accidental?
errors?had?occurred.?For?instance,?mistakes?in?typ?
ing?a? locality?name?made? that? location? inaccessi?
ble? in?Gazetteers? and? changing? label? formats? re?
sulted? in? the? loss?of? information.? To? avoid? these?
and?other?pitfalls,?we? studied? the? types? individu?
ally? and?used? all? the? information? that?we?had? at?
the? time? to? georeference? them.? Access? to? the?
original? label? through?US?Type?Specimen?Register?
Imaging? Project? (http://botany.si.edu/types/)? has?
made?this?task?easier.?
? The? list? below? includes? the? fields? that?we?
found?useful?in?the?georeferencing?process:?
?? Locality?names:?Towns,?mountains,???
?? Elevation.?
?? Distances?and?heading:?1?km?N?from?,?
?? Habitats:?savanna,?forest?edge???
?? Expedition? information:? base? camp,? inter?
mediate?camp???
?? Coordinates.?
We?used?Gazetteers?for?Guyana,?Suriname,?French?
Guiana?and?Venezuela? (Defense?Mapping?Agency?
1993a,?1993b,?1993c,?1993d)?as?a?first?approxima?
tion? of? the? localities? or? when? available,? coordi?
nates? on? the? label.? The? set? of? coordinates?
(transformed? to?decimal?degrees)?were?uploaded?
to? Google? Earth? using? EarthPlot,? (free? software:?
http://www.earthplotsoftware.com/)? which? al?
lows?easy?plotting?of?large?sets?on?Google?Earth.?In?
addition,?we?used?maps?of? the?Shield?area,?some?
published? by? different? agencies? and? available?
through? the? BDG? program? map? collection,? and?
others? from? publications? (i.e.,? Maguire? 1945,?
1948,?Maguire? and? Reynolds? 1955,?Maguire? and?
Wurdack?1959,?Maguire?1981,?Cowan?1952,?Glea?
son?1931,?Hitchcock?et?al.?1947,?Huber?1995,?Tate?
and?Hitchcock?1930).?
? Below? are? two? examples? of? how?we? have?
gathered? and? used? the? information? to? enhance?
the? traditional?georeferencing?of?collecting? locali?
ties.?
Example?1.?(Figure?1)?Some?Types?had?coordinates?
on? their? labels?but?often? these? seemed? to?be? an?
approximation.? For? example,? the? Type? specimen?
of? Rhamnus? marahuacensis? Steyermark? and?
Maguire? (Rhamnaceae)? collected? by? Steyermark?
126049?had? coordinates? that? in?Google?Earth? fell?
at? the? SE? base? of? Cerro?Marahuaca? (Figure? 1B).?
However,? the? label? says? that? the? specimen? was?
collected? at? the? ?summit? of? Cerro?Marahuaca,? in?
the?Fhuif?section?at?2450?2500?m?.?That?area?was?
found? using? a? combination? of? the? Google? Earth?
location?of?the?summit?and?the?elevation;?the?co?
ordinates?were?changed?to?reflect?the?more?accu?
rate?location,?resulting?in?a?15?km?of?distance?from?
the?original?coordinates?(Figure?1A).?
profiles?
?72? ??2010?the?authors;?journal?compilation???2010?The?International?Biogeography?Society???frontiers?of?biogeography?2.3,?2010??
Example?2.?(Figure?2)?Some?collections?have?refer?
ences? to?such? features?as??base?camp,? intermedi?
ate? camp,??? Sometimes? these? expeditions?were?
the?first?exploration?of?an?area,?and?they?produced?
a? large?number?of? types.?This?happened?with?ex?
peditions? conducted? in? the? amazing? table? top?
mountains?or? tepuis? found?on? the?Guiana?Shield.?
An? example? is? the? expedition? conducted? by?
Maguire? to? Tafelberg,? Suriname,? in? 1944.? Tafel?
berg?is?an?isolated?sandstone?Table?Mountain?rep?
resenting? a? remnant? of? a? tepui.? All? of? the? types?
from?this?area?had?been?georeferenced? in?the?da?
tabase? with? the? same? coordinates,? the? summit.?
However,?Maguire?had?published?a?map?with? the?
routes?and?the?names?that?he?gave?to?some?of?his?
collection? localities? (Figure? 2B;? Maguire? 1948).?
Google?Earth?allows?one? to?overlay? images,? such?
as?the?Maguire?map,?on? its?surface?and?therefore?
to? create? a? georegistered? version? (Raes? et? al.?
2009)?of? the?map? (Figure?2C).?The? type?specimen?
of?Sagotia?tafelbergii?Croizat?(Euphorbiaceae;?Fig?
ure? 2E)? collected? by?Maguire? 24802? has? ?North?
Ridge?? as? a? locality? description,? and? having?
Maguire?s? map? overlayed? on? the? image? from?
Google?Earth?allowed?us?to?give?more?precise?co?
ordinates? (Figure?2D)? for?the?ca.?70?types?housed?
at?US?that?were?collected?from?this?expedition.?
? In?addition? to? these?examples,?many?other?
situations?were?encountered?and? locations?subse?
quently?corrected.?To?keep?track?of?these?changes?
new? fields?were? added? to? the? database.? For? in?
stance,?Example?1?had?coordinates?on? its? label?so?
the?new?fields?added?to?the?database?were:?1)?ini?
tial? source:? coordinates? label,? 2)? final? source:?
Google?Earth? interface,?3)?reason?1:? label?descrip?
tion,?4)?reason?2:?elevation.?
? One?might? ask? how? accurate? the? imagery?
and?elevation?data?that?Google?Earth?displays?are.?
Google? Earth? uses?WGS84? Datum? as? coordinate?
system?and?NASA?Shuttle?Radar?Topography?Mis?
sion? data? as? Digital? Elevation? Model? (although?
Google?Earth?may?use?different?elevation?data? in?
some?specific?areas).?We?compared?recent?locality?
information?recorded?by?two?BDG?collectors?(D.H.?
Clarke?s? expedition? to? Mt.? Ayanganna,? Guyana,?
2001? and? K.? M.? Redden?s? expedition? to? Yatua?
River? ,Venezuela,? 2005)? using? GPS? devices? with?
Google? Earth? data;?we? found? the? average? differ?
ence? to?be?50?100?m.? The?number?of? specimens?
and?taxa?studied?and?the?coordinates?provided?are?
summarized?in?Table?1.?
? In? total,? the?whole?process?of?georeferenc?
ing? the? ca.? 3400? Type? specimens? took? eight?
months? (appx.?100? specimens?per?week).?The?di?
rect? results? of? this? study? are? available? as? place?
marks?powered?by?Google?Maps?and?Google?Earth?
that? can? be? downloaded? and? consulted? on? the?
website? http://botany.si.edu/bdg/
georeferencing.cfm.?
? ?
profiles?
?
Figure?1.?(A)?Position?of?the?coordinates?(white?placemark)?
and?position?after?processing?the?label?information.?(B)?Label?
of?Rhamnus?marahuacensis?showing?coordinates.?
 73?frontiers?of?biogeography?2.3,?2010?????2010?the?authors;?journal?compilation???2010?The?International?Biogeography?Society?
profiles?
?
Figure?2.?(A)?Tafelberg?cut?section?at?450?m?asl?on?Google?Earth.?(B)?Tafelberg?expedition?map?(Maguire?1948)??
(C)?Expedition?map?overlaid?on?GE.?(D)?Type?georeferenced.?(E)?Label?of?Sagotia?tafelbergii.?(F)?Point?radius?uncer?
tainty?as?calculated?according?to?Wieczorek?(2004).?The?radius?of?the?circle?represents?the?maximum?distance?error?
for?that?locality,?this?example?uses?the?type?specimen?of?Sagotia?tafelbergii?(Example?2).??The?larger?circle?is?the?un?
certainty?if?the?Gazetteer?coordinates?for?Tafelberg?are?used.??The?smaller?circle?represents?the?uncertainly?when?
using?the?method?described?here.?
?74? ??2010?the?authors;?journal?compilation???2010?The?International?Biogeography?Society???frontiers?of?biogeography?2.3,?2010??
? The?results?are?provided?as?a?single?coordi?
nate?pair?assigned?to?each?location.?That?does?not?
mean?that?the?collections?georeferenced?show?the?
exact? locality.? All? coordinates,? even? those? that?
were?obtained?using?a?GPS?device,?have?an?uncer?
tainty?value?associated?with? them.? In? fact,?uncer?
tainty?is?an?inherent?attribute?of?geographic?infor?
mation? (Goodchild?2001).?Using? the?protocol?de?
scribed? above,?we? think? that?we? have? improved?
the?quality?of?the?data?by? increasing?the?accuracy?
and? thus? reducing? the? uncertainty.? The? uncer?
tainty?value?is?important?because?it?can?determine?
if? the? data? are? suitable? for? a? particular? analysis?
(Rocchini?et?al.?2011).?For?example,?a?plant?locality?
description? saying? ?Banks?of?Potaro? river?,?might?
be?useful? for?a?research?project?on?riparian?vege?
tation,? but? not? for? a? biodiversity? survey? of?
Kaieteur?National?Park?or? to?predict?distributions?
because,?even?though?the?Potaro?River?crosses?the?
Park? it? is? also? outside? of? the? Park? and? it? crosses?
many?vegetation?types.?Data?from?specimen?labels?
have?numerous? sources?of?uncertainty:?precision?
of? the? locality,? unknown? ?datum?? information? on?
maps,? imprecise?distance?measurements?or?direc?
tional? information,?generalized?or? incorrect? coor?
dinates,?etc.?It?can?be?challenging?to?calculate?the?
uncertainty? value? when? combining? uncertainties?
from? different? sources.? Chapman? and?Wieczorek?
(2006)? provide? different? examples? of? calculating?
uncertainty?depending?on?the?locality?information?
and? proposed? the? point?radius? method?
(Wieczorek?et?al.?2004)? to? represent?uncertainty.?
This? method? describes? each? locality? as? a? circle?
where? the? radius? represents? the? maximum? dis?
tance? error? for? that? locality,? storing? the? uncer?
tainty?value?as? the? length?of? the? radius.?The?Bio?
geomancer? Project? (http://
www.biogeomancer.org/)? has? an? application? for?
georeferencing?localities?providing?the?uncertainty?
values?associated?using?this?method.?In?the?case?of?
the?Type?of?Sagotia?tafelbergii?(Example?2):? if? it? is?
georeferenced? using? only? the? Gazetteer? coordi?
nates?for?Tafelberg? its?uncertainty? is?estimated?as?
a? circle?with? a? 7.5? km? radius?which? includes? the?
whole?mountain?(Figure?2F).?Overlaying?Maguire?s?
map?(1945)?on?Google?Earth?allows?the?collection?
to?be?placed?on?the?North?Ridge?thereby?reducing?
the?uncertainty? to?a? circle?with?a?0.85?km? radius?
(Figure?2F).?In?addition,?Guo?et?al.?(2008)?recently?
proposed? a? probabilistic?method? to? represent? a?
locality?with?a?polygon? rather? than?a?circle?which?
tends?to?overestimate?uncertainty.?
? For?our? studies,?we?do?not? include? coordi?
nates? for? those? records? with,? in? our? viewpoint,?
high?uncertainty?values.?In?Table?1,?the?lower?per?
centage? ratio? of? the? three? Guianas? is? explained?
because? the?number?of? ?old?? (historic)? collections?
where?inadequate?locality?information?is?common.?
For? example,? there? are? ca.? 300? types? collected?
from? 1835?1844? by? Robert? and? Richard? Schom?
burgk? with? ?British? Guiana?? or? ?Banks? of? Esse?
quibo?? as? the? only? locality? information.? Despite?
profiles?
?? ?? Total?Specimens? Total?Taxa? Coordinates?
No??
Coordinates?
%??
Georefenced?
French?Guiana? ?? 235? 217? 130? 87? 59.9?
Guyana? ?? 932? 860? 525? 335? 61.0?
Suriname? ?? 258? 239? 156? 83? 65.3?
Venezuela? Amazonas? 1108? 1015? 986? 29? 97.1?
?? Bolivar? 824? 756? 702? 54? 92.9?
?? Delta?Amacuro? 6? 6? 4? 2? 66.7?
Total? ?? 3363? 3093? 2503? 590? 80.9?
?
Table?1.?Results?of?specimens?georeferenced.?The?data?showed?on?this?table?were?taken?at?the?moment?of?present?
ing?the?work?(August?2010).?The?US?National?Herbarium?database?is?being?updated?constantly?and?these?numbers?
may?vary?at?the?present?moment.?
 75?frontiers?of?biogeography?2.3,?2010?????2010?the?authors;?journal?compilation???2010?The?International?Biogeography?Society?
the?extensive?publication?by?van?Dam?(2002),? it? is?
still?difficult?to?find?a?more?precise? locality?and?so?
they? could? not? be?mapped.? Also? excluded? were?
collections?with? locality?names? that? could?not?be?
found?and?others?with? inconsistencies? in? their? in?
formation;?these?may?be?added?in?the?future.?
?
Concluding?remarks?
The? advent?of?new?GIS? techniques? and? their?po?
tential? for? analyzing? and? interpreting? the? large?
quantity? of? data? stored? in? specimen? collections?
creates?a?challenge? for? researchers.?Google?Earth?
has?proven?useful? in? improving? the?quality?of?our?
data?and?we?recommend?its?use?to?others?for?their?
georeferencing? projects.? It? has? an? interface? that?
easily?allows?overlying?maps,?drawing?paths,?add?
ing? information? marks,? measuring? distances,?
checking? the? elevation? of? a? point? and?moving? a?
collection? from?one?place? to? another.? Such? tech?
niques? provide? a? method? to? release? previously?
incorrect?or? ?hidden??data?often? from?ecosystems?
that?are?no?longer?extant.??
? There? is? still? a? lack?of? ?high? resolution?? im?
agery? in?Google?Earth?for?many?of?the?studied?ar?
eas.?Such?updates?would?increase?the?applications?
of? the? tool? in,? for? instance,? overlaying? predicted?
distribution? polygons? over? real? satellite? imagery?
and?modifying? them?according? to? identified?habi?
tats?help?in?the?production?of?more?accurate?vege?
tation?maps,?documentation?of?changes?of?habitat?
or? land? uses,? or? for? planning? future? expeditions.?
Given? the? increased?use?of?online?databases? it? is?
critical? that? the? data? be? checked? and? improved?
(see?Hortal?et?al.?2007)?so?that? it?helps?give?accu?
rate? answer? questions? rather? than? unreliable? re?
sults.?
?
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