Hydrometereology of Tropical Montane Cloud Forests

HYDROLOGICAL PROCESSESHydrol. Process. 25, 465498 (2011)Published online 30 December 2010 in Wiley Online Library(wileyonlinelibrary.com) DOI: 10.1002/hyp.7974

Hydrometeorology of tropical montane cloud forests:emerging patterns

L. A. Bruijnzeel,1* Mark Mulligan2 and Frederick N. Scatena31 Faculty of Earth and Life Sciences, VU University, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands

2 Environmental Monitoring and Modelling Research Group, Department of Geography, Kings College London, Strand, London WC2R2LS, UK

3 Department of Earth & Environmental Science, Hayden Hall, University of Pennsylvania, 240 South 33rd Street, Philadelphia, PA 19104, USA

Abstract:Tropical montane cloud forests (TMCF) typically experience conditions of frequent to persistent fog. On the basis of thealtitudinal limits between which TMCF generally occur (8003500 m.a.s.l. depending on mountain size and distance to coast)their current areal extent is estimated at 215 000 km2 or 66% of all montane tropical forests. Alternatively, on the basis ofremotely sensed frequencies of cloud occurrence, fog-affected forest may occupy as much as 221 Mkm2. Four hydrologicallydistinct montane forest types may be distinguished, viz. lower montane rain forest below the cloud belt (LMRF), tall lowermontane cloud forest (LMCF), upper montane cloud forest (UMCF) of intermediate stature and a group that combines stuntedsub-alpine cloud forest (SACF) and elfin cloud forest (ECF). Average throughfall to precipitation ratios increase from072 007 in LMRF (n D 15) to 081 011 in LMCF (n D 23), to 10 027 (n D 18) and 104 025 (n D 8) in UMCFand SACFECF, respectively. Average stemflow fractions increase from LMRF to UMCF and ECF, whereas leaf area index(LAI) and annual evapotranspiration (ET) decrease along the same sequence. Although the data sets for UMCF (n D 3) andECF (n D 2) are very limited, the ET from UMCF (783 112 mm) and ECF (547 25 mm) is distinctly lower than thatfrom LMCF (1188 239 mm, n D 9) and LMRF (1280 72 mm; n D 7). Field-measured annual cloud-water interception(CWI) totals determined with the wet-canopy water budget method (WCWB) vary widely between locations and range between22 and 1990 mm (n D 15). Field measured values also tend to be much larger than modelled amounts of fog interception,particularly at exposed sites. This is thought to reflect a combination of potential model limitations, a mismatch between thescale at which the model was applied (1 1 km) and the scale of the measurements (small plots), as well as the inclusion ofnear-horizontal wind-driven precipitation in the WCWB-based estimate of CWI. Regional maps of modelled amounts of foginterception across the tropics are presented, showing major spatial variability. Modelled contributions by CWI make up lessthan 5% of total precipitation in wet areas to more than 75% in low-rainfall areas. Catchment water yields typically increasefrom LMRF to UMCF and SACFECF reflecting concurrent increases in incident precipitation and decreases in evaporativelosses. The conversion of LMCF (or LMRF) to pasture likely results in substantial increases in water yield. Changes inwater yield after UMCF conversion are probably modest due to trade-offs between concurrent changes in ET and CWI.General circulation model (GCM)-projected rates of climatic drying under SRES greenhouse gas scenarios to the year 2050are considered to have a profound effect on TMCF hydrological functioning and ecology, although different GCMs producedifferent and sometimes opposing results. Whilst there have been substantial increases in our understanding of the hydrologicalprocesses operating in TMCF, additional research is needed to improve the quantification of occult precipitation inputs (CWIand wind-driven precipitation), and to better understand the hydrological impacts of climate- and land-use change. Copyright 2010 John Wiley & Sons, Ltd.

KEY WORDS cloud forest; cloud-water interception; fog; evaporation; rainfall interception; stemflow; throughfall; transpiration;wind-driven rain

Received 2 November 2010; Accepted 3 December 2010

INTRODUCTIONTropical montane cloud forests (TMCF) are typicallyfound in foggy, wet and often windy environments whoseecological and hydrological functioning have puzzled andchallenged investigators for decades. Apart from being

* Correspondence to: L. A. Bruijnzeel, Faculty of Earth and Life Sci-ences, VU University, De Boelelaan 1085, 1081 HV Amsterdam, TheNetherlands. E-mail: [email protected] This paper is partly derived from a chapter previously published asBruijnzeel LA, Kappelle M, Mulligan M, Scatena FN. 2010. Tropicalmontane cloud forests: state of knowledge and sustainability perspec-tives in a changing world. In Tropical Montane Cloud Forests. Sciencefor Conservation and Management, Bruijnzeel LA, Scatena FN, Hamil-ton LS (eds). Cambridge University Press: Cambridge, UK; 691740(www.cambridge.org/9780521760355).

amongst the worlds most valuable terrestrial ecosystemsin terms of species richness and levels of endemism[see Bruijnzeel et al. (2010a,b) for a recent overview],headwater areas with TMCF also provide a stable supplyof high-quality water that is indispensable for maintainingirrigation, hydro-electric power generation and drinkingwater (Zadroga, 1981; Brown et al., 1996; Tognetti et al.,2010). Although cloud forests are often referred to asa single category, it is helpful to distinguish between(1) tall-statured lower montane cloud forest (LMCF),(2) upper montane cloud forest (UMCF) of intermediatestature and (3) stunted sub-alpine (SACF) and elfincloud forests (ECF). The rationale for making sucha distinction lies in the wetter and cooler conditions

Copyright 2010 John Wiley & Sons, Ltd.

466 L. A. BRUIJNZEEL, M. MULLIGAN AND F. N. SCATENA

generally encountered as one moves from the lowermontane to the upper montane and sub-alpine belts, andwhich are known to affect the hydrological and ecologicalfunctioning of the respective forest types (Grubb, 1977;Silver et al., 1999; Bruijnzeel, 2001; Gerold et al., 2008;Benner et al., 2010; Roman et al., 2010).

The wet and generally remote and difficult terrainof the worlds TMCF has not only made them hydro-logically and ecologically unique but also given themsome de facto protection in the past compared to tropi-cal forests situated in more accessible areas. However, inthe late 1970s and early 1980s, it became apparent thatin many parts of the world TMCF were rapidly beingconverted and in need of more formal forms of pro-tection (LaBastille and Pool, 1978; Stadtmuller, 1987).Indeed, between 1981 and 1990, montane forests acrossthe tropics were being lost at a faster rate than low-land tropical forests (11% vs 08% year1, respectively;Doumenge et al., 1995). Two recent inventories estimatedthat around the year 2000 about 4555% of all cloud-affected forests located between 235 N and 35 S hadbeen converted to other forms of land use (Mulligan,2010; Scatena et al., 2010). Conversions to agriculturaland grazing lands, excessive timber harvesting, invasionsby exotic species, road ingressions and various types ofdevelopment have been identified as threats to TMCFin all regions, whereas mining, fire, forest clearing fordrug cultivation and other activities like golf courses orcommunication facilities can be locally important (Hamil-ton et al., 1995; Bruijnzeel and Hamilton, 2000; Kap-pelle and Brown, 2001; Bubb et al., 2004; Hemp, 2005a;Asbjornsen and Garnica-Sanchez, 2010; Mulligan, 2010).In recent years, climatic warming and drying relatedto global or regional climate change have become anincreasingly important factor that can potentially threatenTMCF hydrological functioning (Lawton et al., 2001;Hemp, 2005a; Ray et al., 2006), in addition to havinga devastating effect on particularly vulnerable plant andanimal groups like mosses and amphibians (Pounds et al.,1999, 2006; Nadkarni and Solano, 2002; Williams et al.,2003).

Whilst it is broadly recognized that all of these threatscan impact the hydrological functioning of headwaterareas with TMCF, the scientific information required toquantify these impacts and to help manage these uniquebut vulnerable ecosystems was largely lacking until com-paratively recently. In 1993, the First International Sym-posium on TMCF was held in San Juan, Puerto Rico, theproceedings of which (Hamilton et al., 1995) containedthe first overview of what was known hydrologicallyof TMCF at the time (Bruijnzeel and Proctor, 1995)as well as one of the first physically based studies ofcloud-water interception (CWI) in a TMCF setting (Juvikand Nullet, 1995a). Certain aspects of CWI and TMCFhydrology have been considered at a series of Confer-ences on Fog and Fog Collection (held every three yearssince 1998; Schemenauer and Bridgman, 1998; Scheme-nauer and Puxbaum, 2001; Rautenbach and Oliver, 2004;Biggs and Cereceda, 2007; Climatology Working Group,

2010). Arguably, however, the San Juan Symposiummarked the start of increased research activity in thefields of TMCF hydrology, hydrometeorology and eco-physiology. Thus, whilst Bruijnzeel and Proctor (1995)were able to list only eight studies of crown drip andoccult precipitation in TMCF environments, plus a meresix studies estimating overall evaporation loss throughindirect methods and none quantifying transpiration ratesin TMCF or the impact of TMCF conversion on stream-flow amounts and seasonal distribution, at the follow-upSymposium on Science for the Conservation and Man-agement of TMCF held in 2004 in Waimea, Hawaii(Bruijnzeel et al., 2010a), some 25 presentations reportedon hydrometeorological and plant physiological work thathad been conducted since 1993. Quantitative evidence onthe effects of TMCF conversion to pasture, as well as onthe impacts of climatic variability and change were givenin another ten presentations.

The presence of cloud forest is widely assumed toincrease streamflow volumes, not only because of theextra amounts of water captured from passing fog,beyond that provided by precipitation, but also becauseof reduced evaporative losses under the prevailing lowradiation levels and high atmospheric humidity (cf.Zadroga, 1981; Calvo, 1986; Jarvis and Mulligan, 2011).In addition, the forest helps to reduce the number ofshallow landslides and prevents surface erosion, therebymaintaining better water quality (Sidle et al., 2006;cf. Bruijnzeel, 2004). Such considerations lie at theheart of many payment for ecosystem services (PES)schemes in which downstream users pay a certain fee for(mostly hydrological) services rendered by cloud forestto compensate upstream forest owners who conserve theircloud forests instead of converting them to economicallymore profitable forms of land use such as grazingor cropping (Pagiola, 2002; Rodriguez-Zuniga, 2003).Given the great pressure on the worlds remaining cloudforests, and the growing recognition of their value astreasure houses of biodiversity and as providers of high-quality water, an array of PES-initiatives aimed at TMCFconservation has emerged in recent years (Asquith andWunder, 2008; Munoz-Pina et al., 2008; Porras et al.,2008; Garriguata and Balvanera, 2009; Tognetti et al.,2010). Needless to say, such PES schemes and land-and forest managers and policy-makers in general needto determine which cloud forests under their jurisdictionprovide the best water supplies (and to whom), which arethe most vulnerable to climate change or most threatenedby encroachment, and what are the hydrological impactsassociated with forest conversion or climate change. Inshort, there is a great need for site-specific informationon TMCF hydrological functioning for incorporation intoconservation and management plans at various spatialscales (Bruijnzeel et al., 2010b).

After first defining the various types of cloudforests and exploring their global distribution, thisarticle summarizes the currently available knowl-edge on the hydrometeorology of TMCF and provides

Copyright 2010 John Wiley & Sons, Ltd. Hydrol. Process. 25, 465498 (2011)

HYDROMETEOROLOGY OF TROPICAL MONTANE CLOUD FORESTS 467

Table I. Summary of key structural characteristics marking the chief tropical (montane) forest types distinguished in the presentpaper (based on Frahm and Gradstein, 1991; Whitmore, 1998)

Forest formationa LERF LMRF/LMCF UMRF SACF

Canopy height 2545 m 1533 m 1518 m 159 mEmergent trees Up to 67 m tall Often absent, up to 37 m Usually absent, up

to 26 mUsually absent, up

to 15 mCompound leaves Abundant Occasional Rare AbsentPrincipal leaf size classb Mesophyllous Meso-/notophyllous Microphyllous Nanophyllous

Leaf drip-tips Abundant Present Rare or absent AbsentButtresses Frequent and large Uncommon, and small Usually absent AbsentCauliflory Frequent Rare Absent AbsentBig woody climbers Abundant Usually absent Absent AbsentBole climbers Often abundant Frequent to abundant Very few AbsentVascular epiphytes Frequent Abundant Frequent Very rareNon-vascular epiphytes

(mosses, liverworts)Occasional Occasional/Abundant

80%

a LERF, lowland evergreen rain forest; LMRF/LMCF, lower montane rain/cloud forest; UMCF, upper montane cloud forest; SACF, sub-alpine cloudforest.b Leaf sizes according to the Raunkiaer classification system: mesophyllous, 450018 225 mm2; notophyllous, 20254500 mm2; microphyllous,2252025 mm2; nanophyllous,


As elevation continues to increase, the trees become grad-ually smaller, moss cover on the stems increases from


Figure 1. Modelled distribution of cloud-affected tropical montane forests, with UNEP-WCMC listed cloud forest sites indicated in red. The colourscale indicates the approximate fractional cover of forest within the 1-km pixel

variation in the actual elevations at which the cloudforests occur (Table II) and in their spatial extent indifferent continental regions (Table III and Figure 1).In general, the distributions depend on the upper andlower bounds of the cloud belt (Table II) and on theglobal, regional and local factors that influence cloudformation. As stated previously, the transition fromLMCF to UMCFas well as the thickness of the cloudforest belt itselfis primarily governed by the levelof persistent cloud condensation (Grubb and Whitmore,1966; Frahm and Gradstein, 1991; Kitayama, 1995). Thelatter, in turn, is determined by the moisture content and

temperature of the atmosphere such that the more humidthe uplifted air, the lower will be the altitude at whichit condenses (Foster, 2010). With increasing distancefrom the ocean, the air tends to be less humid and willrequire lower temperatures, and thus higher elevations, toreach condensation. Consequently, the associated cloudbase, and thus the presence of TMCF, will occur at ahigher elevation as one is moving away from the ocean.Similarly, for a given atmospheric moisture content, thecondensation point is reached more rapidly for coolair than for warm air (Foster, 2010). Hence, at greaterdistance from the equator, the average temperatureand



therefore the altitude at which condensation and TMCFoccurwill be lower (Nullet and Juvik, 1994; Jarvis andMulligan, 2011).

In addition to the elevation of the cloud base, thedistribution and extension of the TMCF belt is alsogoverned by the upper limit of cloud formation, whichis also influenced by global-scale atmospheric circulationfeatures, such as the Hadley cell. In the latter, heated airrises to great elevations in the equatorial zone, and flowspolewards and eastwards in the upper atmosphere as itcools. The cool dry air then descends in a broad belt in theouter tropics and sub-tropics from where it returns to theequator. This subsidence reaches its maximum expressionat oceanic sub-tropical high-pressure centres and alongthe eastern margins of the oceanic basins. As the airdescends and warms, it forms a temperature inversionthat separates the moist layer of surface air (being cooledwhilst rising) from the drier descending air above. Thisso-called trade wind inversion (TWI) forms a surfacethat generally rises towards the equator and from east towest across the oceans (Riehl, 1979). Over the easternPacific Ocean, the TWI occurs at only a few hundredmetres above sea level, for example, off the coast ofsouthern California. It rises to about 2200 m near Hawaii(Cao et al., 2007) and dissipates in the equatorial westernPacific (Nullet and Juvik, 1994). The consequences ofthe TWI for the occurrence of the upper boundary ofTMCF are profound and are another reason why thevegetation zonation on mountains situated away fromthe equator tends to be compressed. For instance, somewindward slopes in the Hawaiian archipelago receivemore than 6000 mm of rain year1 below the inversionlayer. However, above the inversion, montane cloudforest suddenly gives way to dry sub-alpine scrub becausethe inversion prevents clouds moving upward and bringmoisture to those areas (Kitayama and Muller-Dombois,1994a,b; cf. Loope and Giambelluca, 1998).

Superimposed on these global-scale moisture and tem-perature gradients are more local processes influencingthe temperature of the air column and thus the start-ing point for air subject to cooling by lifting. Theseinclude the influence of offshore sea surface tempera-tures, landsea interactions involving the coastal plain,the size of a mountain and its orientation and expo-sure to the prevailing winds (Malkus, 1955; Van Steenis,1972; Stadtmuller, 1987; Jarvis and Mulligan, 2011). Theinteractions of these local and regional influences on thedistribution of TMCF can be quite pronounced. The sheermass of large mountains exposed to intense radiation dur-ing cloudless periods is believed to raise the temperatureof the overlying air sufficiently to decrease the lapserate and enable plants to extend their altitudinal range.This effect is commonly referred to as the mass ele-vation or telescoping effect and has been recognizedfor many decades (Schroter, 1926; Van Steenis, 1972;Whitmore, 1998). More recent research has indicated thatlow-statured, mossy forests occurring at relatively lowelevations (


still remains and that some 272 Mkm2 of CAF havebeen converted (Mulligan, 2010). Whilst there is rea-son to believe that the hydro-climatic approach slightlyover-estimates the area with TMCF [see detailed discus-sion by Mulligan (2010)], the results were tested witha high level of success against the more than 560 trop-ical sites listed by WCMC-UNEP as having confirmedcloud forest presence (Aldrich et al., 1997). The best fitbetween actual and modelled cloud forest presence wasobtained when using a threshold value for ground-levelcloud occurrence (i.e. fog) of at least 70% of the time(Mulligan, 2010; Figure 1). It is recognized that this isa relatively high level of fog occurrence, but the use ofeither higher or lower values of fog frequency resulted insignificant reductions in the proportion of observed cloudforests being correctly modelled as CAF [see Mulliganand Burke (2005b) for details on the models sensitivity].

CLOUD FOREST HYDROMETEOROLOGY

General climatic conditionsThe more than 560 tropical sites with confirmed cloud

forest presence (albeit unspecified in terms of cloudforest type; Aldrich et al., 1997; Figure 1) represent awide range of climatic conditions (rainfall and temper-ature, wind) and landscape settings (altitude, exposure,mountain size, distance to sea, bedrock geology). Jarvisand Mulligan (2011) employed spatial data sets derivedfrom the WorldClim data-base (Hijmans et al., 2004), todescribe the climate at 477 cloud forest sites as identi-fied by UNEP-WCMC. Further, comparisons were madebetween the climate of cloud forest sites and that of ran-domly generated sites covering forested areas throughoutthe montane tropics, with the aim of identifying the cli-matic variables most important in distinguishing TMCFfrom other tropical forests. TMCFs were found to be wet-ter (by 184 mm year1 on average), cooler (by 42 C onaverage) and less seasonally variable than other mon-tane forests. The most statistically significant differencesin climate between TMCFs and other montane forestswere: maximum temperature, mean temperature, rainfalland rainfall seasonality (in order of significance). Cloudforests also tend to be located closer to the coast (particu-larly in Asia) and at higher altitudes than montane forestsnot affected by cloud. Furthermore, cloud forests occupymore topographically exposed areas than do other mon-tane forests. Interestingly, cloud forest sites in Africa tendto be drier (average annual rainfall 500 m;Pruppacher and Klett, 1978), and CWI is fundamental toassessing the hydrological importance of intact and con-verted cloud forest areas. Because it is difficult to distin-guish drizzle from rain in precipitation records, the termprecipitation is used in this article to denote either. Like-wise, the term wind-driven precipitation (WDR) refersto either form of near-horizontal precipitation, whereasthe term occult precipitation (HP) is used to denotethe sum of CWI and WDR without making a distinctionbetween the two (cf. Frumau et al., 2011a). The impor-tance of occult contributions is illustrated by the resultsobtained by several early studies from Central Amer-ica that arguably contributed greatly to the reputationof TMCFs as suppliers of high amounts of streamflowthroughout the year. Zadroga (1981) compared the rain-fall and streamflow regimes for two groups of catchmentsin northern Costa Rica, one located on the (wetter) wind-ward Atlantic side of the Continental Divide and theother on the (drier) leeward Pacific side. Annual stream-flow from the Pacific catchments amounted to 34% ofthe rainfall and showed a clear seasonal flow patternthat followed that for rainfall, whereas annual streamflowfrom the Atlantic catchments roughly equalled rainfall(102%), and even exceeded rainfall inputs for seven outof 12 months (Figure 2). Whilst acknowledging that thehigh runoff coefficient derived for the Atlantic catch-ments was partly due to underestimation of rainfall inputsin the higher, rainier parts of the catchments that lackedrainfall measurement stations, Zadroga (1981) attributedthe very high streamflows primarily to unmeasured inputsof CWI. He also emphasized the fact that months withexcess streamflow over precipitation coincided with thedominant occurrence of moisture-laden clouds broughtin from the Caribbean by the trade winds. In addi-tion, Zadroga recognized that evaporative losses fromthese fog-ridden slopes should be low. These contentionswere subsequently confirmed by measurements of rain-fall, streamflow and climatically based estimates of evap-otranspiration for another Atlantic catchment located fur-ther south in Costa Rica (Calvo, 1986). Although bothof these early investigations must be considered blackbox studies that did not quantify the underlying hydro-logical processes, further support came from comparativeobservations of rainfall and throughfall (TF) in Atlanticcloud forests in Puerto Rico (Weaver 1972), Costa Rica(Caceres, 1981) and Honduras (Stadtmuller and Agudelo,1990). These studies indicated that annual TF at exposedlocations could attain values of as much as 110180%of measured rainfall.

To what extent are these early observations exemplaryfor the hydrological behaviour of TMCF in general?And how reliable are such direct comparisons of rain-fall and TF in view of such potentially disturbing factorsas wind-induced precipitation losses around rain gauges(e.g. Frland et al., 1996; Yang et al., 1998; Nespor andSevruk, 1999) and the effect of inclined precipitationfalling onto steeply sloping terrain as opposed onto a



Figure 2. Contrasting rainfall and streamflow regimes for catchments situated on the Atlantic and Pacific slopes of northern Costa Rica (afterZadroga, 1981)

horizontal gauge orifice (Sharon, 1980; Herwitz and Slye,1992), relative to unmeasured contributions by CWI orWDR? Earlier reviews of the hydrometeorological litera-ture on TMCF (Bruijnzeel and Proctor, 1995; Bruijnzeel,2001, 2005) lacked sufficient data for a meta-analysisbut the proliferation of local studies of net precipitation(or at least of TF)many of which are reported byBruijnzeel et al. (2010a)now allows an analysis ofsome of these questions and whether different types ofTMCF do indeed exhibit different net precipitation frac-tions.

Table IV lists net precipitation data for lower montanerain forests that are little or not affected by fog and lowcloud (LMRF, n D 15), tall LMCF subject to moderatefog incidence (n D 23), UMCF of intermediate staturesubject to frequent fog incidence (n D 18) and stuntedSACF and ECF (n D 8). Figure 3 shows the averageamounts of rainfall (P), the fraction of rainfall becomingTF, and the leaf area index (LAI) for the respectivemontane forest types, whereas Figure 4 shows scatterplots of annual TF versus P at individual study sitesgrouped per forest type.

On the basis of the more than 60 local studies listedin Table IV, the following patterns emerge: (1) averageLAI values per forest type decrease from 554 181in LMRF through LMCF (467 111) and UMCF(396 125) to 310 121 in SACFECF; (2) P atSACFECF sites tends to be higher on average thanat sites representing the other three forest categories forwhich differences between groups were comparativelysmall and (3) averaged ratios of TF to P increase steadilyfrom LMRF to SACF, viz. from 72 7% (SD) in LMRF,to 81 11% in LMCF, 100 27% in UMCF, and 104 25% in SACFECF (Figure 3).

Rigorous comparisons of the statistical differences inTF/P between the different forest types is limited by thesmall and uneven sample sizes as well as by differencesin the sampling methodologies used in the studies of

both TF and P. Nevertheless, comparisons of means andmedians using t-tests, MannWhitney rank sum testsand analysis of variance (ANOVA) where appropriate,do support the patterns observed in Figure 3. Moreover,there are significant differences (at p D 005) betweenthe means or medians of TF/P for UMCF and bothLMCF and LMRF (but not SACFECF). The medianTF/P value for LMCF is also significantly higher thanthe median value for LMRF.

Comparison of the slopes of the P versus TF graphsper forest type (Figure 4) also indicates that TF exceedsprecipitation as measured in the open at SACFECFsites, whereas the two are nearly equal at UMCF sites.To these TF fractions the fraction of P reaching the forestfloor as stemflow (SF) should be added. Unfortunately,not all studies of net precipitation have measured SFbut values observed in LMRF and LMCF are typicallyvery low (


Tabl

eIV

.Thr

ough

fall

(TF)

,ste

mflo

w(S

F)an

dap

pare

ntra

infa

llin

terc

eptio

n(E

i)fra

ctio

ns(%

of

inci

dent

prec

ipita

tion)

and

appa

rent

clou

d-w

ater

inte

rcep

tion

(CW

I,m

mye

ar1

;c

Dv

alue

corr

ecte

dfo

rwin

dan

dto

pogr

aphi

cef

fect

s)as

mea

sure

din

diffe

ren

tty

pes

oft

ropi

calm

on

tane

rain

fore

st

Loca

tion

and

fore

stty

peEl

evat

ion

(m.a.

s.l.)

MA

Pa(m

m)LA

I/H/

(m)

TFSF

(%o

fP)

Ei

CWI

(mm

year

1)

Rem

arks

Mon

tane

rain

fores

tslit

tlea

ffect

edby

fogB

oliv

ia,Y

un

gasb

1850

2310

/20

79

Documents

Hydrometereology of Tropical Montane Cloud Forests