Tropical Mountain Ecossystem UNESCO

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IUBS Unesco MWCOMPARATIVE STUDIES ON

TROPICAL M O m A I N ECOSYSTEMSPlanning for research

Edited byM. Monasterio, Go Sarmiento and 0.T. Solbrig

SPECIAL ISSUE- 12


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COMPARATIVE STUDIES ON TROPICAL MOUNTAIN ECOSYSTEMS:PLANNING FOR RESEARCH

R e p o r t o f t h e m e e t i n g o f t h e I U BS W o r ki ng G r o u p o nT r o p i c a l M o u n t a i n E c o s y st e m s / D e c a d e o f t h e T r o p i c s P r o g r a mCO-sponsoredw i hT h e U N E S C O / M a n a n d B io s p h e r e P r o g r a mandT h e U n i v e r s i d a d d e L o s An d e s ( U L A ), M e r i d a , V e n e z u e la

2 - 8 Jun e, .1985Mer ida , Venezue la

E d i e d b y

P r o f e ss o r M a x i m i n a M o n a s t e r i oF a c u l t a d d e C i e n c ia sU n i v e r s i d a d d e L o s A nd e sMer ida , Venezue laP r o f e ss o r G u i l l e r m o S a r m i e n t oF a c u l t a d d e C i e n c ia sU n i v e rs i d a d d e L o s A n d e sMer ida , Venezue la

andPro fessor O t t o T. S o lb r igD e p a r t m e n t o f O r g a n i s m i c an d E v o l u t i o n a r y B i o l o g yH a r v a r d U n i v e r s i ty2 2 D i v i n i t y A v e n u eCam bridge , M A 02138, U.S.A.

SPECIAL ISSUE - 12BIOLOGY INTERNATIONAL

T h e I n t e r n a t i o n a l U n i o n o f B i o l o g i c a l S c ie n ce sN e w s M a g a z i n e


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This report outlines an International Program of Researchon Tropical Mountain Ecology. It was outlined at a meetingheld June 2-7, 1985, in Merida, Venezuela, hosted by theFaculty of Sciences of the Universidad de los Andes, andcosponsored by th e International Union of Biological Sciencesand the Man and the Biosphere Program of UNF.SCO.

The report outlines the objectives and the philosophy ofthe program, and presents the reports of three working groupsappointed at Merida for that purpose. Various individuals wererequested to prepare different parts of the manuscripts, asfollows: Prof. Bruno Messerli (Introduction); Profs. MaximinaMonasterio and Guillermo Sarmiento (Central Theme); Profs.Dieter Muller-Dambois and Thomas van der Hammen (TransectStudies); Profs. Aura Azocar, Guillermo Goldstein, MaximeLamotte, Fermin Rada, Dr. Irene Garay and Mr. Jaime Cavallier(Ecosystem Studies), and Prof. Guillermo Sarmiento (Land UsePatterns). However al1 partakers in the meeting (for a list ofnames see the back pages of this issue) participated in thepreparation of one or more of th e reports, which were thendiscussed by the entire group.

The meeting was preceeded by a series of presentations onthe geology, biology, and archeology of the area, supplementedby a field trip. The organizers of the meeting wish to thankal1 the participants for their contributions, but very espe-cially Drs. Maria-Lea Salgado-Labouriau, Erica Wagner, CarlosSchubert, and Dimas Malagon. Finally we wish to thank al1 thelocal organizers who worked so hard to organize this meeting.


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COMPARATIVE STUDIES ON TROPICAL MOUNTAIN ECOSYSTEMS.Proposal For a Proaram of Research

This document represents a proposa1 for a program ofcollaborative research on tropical mountain e c o s y s t ems . Ourconcern stems from the present trends of degradation of tropi-cal mountain ecosystems, involving changes in productivity thatare severely affecting the stability of th e ecosystem ,and ofthe human societies that live there. In order to providebetter guidelines and management options we need to improve Ourunderstanding of the working of the natural and human compo-nents of Tropical Mountain Ecosystems, and of prevailing andprojected patterns of land use. Consequently, t he objectives ofa collaborative research program on tropical mountain ecosys-tems are as follows:1. To gain an understanding of the functioning and produc-tivity of natural ecosystems at different altitudes and levelsof slope.2. To analyze the interrelationships between naturalecosystems and prevailing patterns of land use, especiallybetween the natural system potential and the impact of man'sactivities (technological input) in order to determine thecarrying capacity.3. To identify and validate general principles of inte-grated development programs and resource management, and futuremanagement strategies in order to preserve the fragile andhighly diversified mountain ecosystems of the tropics.

SECTION 1: INTRODUCTION AND OWECTIVES,Natural and human svstems: an intearatad avvroach.Any research program has to be based on an integratedapproach, taking into account the interrelationships betweenthe natural and human systems. In fig. 1 we represent thefundamental structures and processes that occur in any poten-tial study area. Relation one shows the influence of externalfactors on the system, especially on the socio-economic compo-nent. The latter can be divided into several subsystemsdepending on the local conditions (e.g. economic, political,demographic, cultural, etc.). Al1 the activities originating


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F i g u r e 1: S t ruc tu re s and p rocess es in a schematic regional Ecological -Econornic System (Modified from MESSERLI, B . a n d P . , 1978)

t f F E C T S ONNE IGIIBOUR I NG

AREAS

llighland -lowlandinteractionsin muuntainsystems

Delimitation of a test area external factors- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -interna1 factors-1I I

4

Interna1 relations Relations betveen the main systems

-

EXTERNALFACTORS

DEMAND FORNatural re-sources

Agriculturalproducts

Recreationalactivities

P O L I T I C A LMEANS

Land useplanning

Economicdevelopment

Environmentalprotection


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from this socio-economic system determine through the kind oftechnological input the type and the intensity of land use(relation two). If these activities are in equilibrium withnatural conditions, there will be positive feedback from theland to the economic system in the form of yields or producti-vity of the land (relation three). But if this interactionleads to damage or destruction in the natural system negativefeedbacks affecting land and its usefulness, and eventuallyalso the economic system will take place (relations four andfive). This general model must be adapted to every localcondition. Even though it does not provide quantitativeanswers it is helpful i n trying to understand the functioningof a very complex system and aids in recognizing destabilizingprocesses and to coordinate remedial action. Binally, such amodel can help as an instrument of communication for an inter-disciplinary group of scientists, encouraging every participantt o adopt methods and findings of other disciplines.osvstems in aountain ec r a n d and continuous change

Al1 over the world we can observe rapid changes takingplace in mountain ecosystems. With a growing world populationand increasing migration into mountain areas, with the con-struction of roads and other systems of communication, with theinfluence of new economic, cultural and technological elementson the traditionally self-sufficient agricultural societies,rapid and often uncontrolled changes with damaging effects onthe natural environment and its stability are taking place.Until now, mountain societies were more or less closed systems.After centuries of experimentation these.societies often hadacquired an equilibrium with the natural environment, anequilibrium that can be determined qualitatively and quantita-tively in terms of plant and animal production, calories andgrams of protein. It is fascinating to see how societies ofvery different cultural backgrounds, from the Andes, to theHimalayas, and Africa, tried to regulate the number of inhabi-tants in order to preserve the sensitive and fragile environ-ment in which they lived and to optimize production. A similarbehavior could be observed until the end of the last century inthe European Alps (fig. 2).

With the opening of mountain systems to outside interven-tion, the natural and human mountain systems became morecomplex, more difficult t o understand, more uncontrolled in itsdevelopment, and less stable. In general more resources areexploited than are produced, unexperienced persons are involvedin the decision making process regarding land use, al1 in order


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Figure 2: The ongoing qualitative and quantitative change from moreor less closed to open systems in mountain villages andvalleys (Modified from MOSER, W., 1975).CLOSED SYSTEM

NPRODUCTIV

4

ALPINE NPRODUCTIVPASTURE

INPUT and OUTPUT of : People (permanent and seasonal migration),capital, energy, technology, informat iun,goods and services in different forns.

INHABITANTS WATERSubsistenceAgriculture

FORESTA

GRASSLAND ARABLELAND

e-)


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to satisfy the economic needs of surrounding lowland areas. Anur~controlled growing population creates new problems. So, forexample, denied the opportunity to emigrate, landless inhabi-tants as a last resource cut down forests that have protectedslopes for centuries. Deforestation is occurring in al1tropical mountains, but especially in Africa and the Himalayas.

These changes will probably intensify in tropical mountainareas in the near future. By the end of the century al1 closedmountain systems will have disappeared. There is therefore anurgent need to implement programs such as the mountain programof the Decade of the Tropics, in order to find ecologically-sound solutions to the problems of tropical mountains in orderto avoid irreversible damage and to encourage ecologicallyoriented development programs based on reliable scientificdata.The mountain ~ e r i ~ h e r ~nd the Power of the economic center

Tropical mountains can be favored zones for cash cropssuch as coffee, tea, fruits, and vegetables. However theconsumption of these and other mountain products is outside themountain area in urban centers, or tourist centers. Marketprices for these commodities conform to national and worldeconomic policies. This means that a remote political centermakes decisions that affect land use patterns in the mountainsand the income of their population. So, for example, a highercoffee price, fixed and guaranteed by the government, canchange immediately the land area devoted to coffee in themountain areas. Not only a national authority, but the worldeconomic conditions can have similar effects. Falling interna-tional coffee prices may result in the substitution of coffeeby wheat, maize, livestock, etc., and this, in turn can createa need for more land which can lead to deforestation and/orerosion. Land use in tropical mountains is a delicate balancebetween people's needs and activities and the requirements forstability of the mountain ecosystem. This balance can easilybe disturbed by wrong decisions made in a remote politicalcenter (fig.3). These decisions concern not only mountainagriculture, but also forestry, tourism, and use of resourcessuch as water, and minerals. Even the establishment ofnational parks is decided by the central authority, oftenwithout consultation and thereby risking a loss of understand-ing and motivation of the local population required for theprotection of the plants and animals in th e park. Otherpolitical and legal factors can also influence land use pat-terns. For instance, if a farmer has to pay more than 50% of


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F i g u r e 3: T h e mo i i nt a i n p e r i p h e r y a n d t h e p ow er o f t h e e c o n om i c c e n t r e

RESEARCH AND DEVELOPMENT 1N MOUNTA l N ECOSYSTEMS

CONSERVAT I ON ENERGY Pl lN lN G TOUR I SMOF NATURE WATER l NDUSTRY.

ECONOM l CCENTER

ENVI RONMENT IB l MPACT

/

2

AGR I CULTURE FOREST CONSERVAT I N ENERGY FI I r~ NG TOUR I SMOF NATURE WATER l NDUSTRY

+


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his yield in fees to an absentee landowner in an urban centerhe may not have the capital to improve his farming methods.Any study of tropical mountain ecosystems has to take intoconsideration the physical and social location of the responsa-bilities for land use. The result of scientific field work,especially that dealing with the limits of productivity andstability, has to be disseminated nation-wide, so that thecenters of political and economic power and decision-makingunderstand how their decisions can affect the fragile mountainecosystem.

e UC 'O th ~ r o d i n svs em in relation to the nat.ural~vcrtarn apolitical and economic decisiosAccording to Winiger ( 1984 ) agricultural ecosystems mustconsider the production strategy in terms of the input andoutput of energy. This is determined by the environmentalconditions and the production goals (whether subsistence orcommercial) set by the society concerned. This concept isexpressed graphically in fig. 4 in four different scenarios:(1) the natural ecosystem within which energy is recycLed andthe total standing biomass is relatively large; (2) what wecal1 the adapted agricultural syatem in which some portion ofthe biomass is available for human consumption but a stablesystem is maintained through the compensatory input of ensrgyfrom within the human component of the system. Such a system istypified by a subsistence farming economy that remainsunchanged over two to three generations. (3) The compromiseagricultural system shows significant human impact and involvesexport of farm products balanced by the introduction of energysuch as artificial fertilizers. A much higher level of produc-tion is attained but at the cost of a reduction in totalstanding biomass, such as is seen in parts of the Andes ofVenezuela. (4) The degraded agricultural system, where thereis a still further reduction in standing biomass, yields can bevery high, but there is complete spatial dislocation and

stability is maintained only by considerable inputs of externalenergyAn understanding of these four scenarios, combined withscientific data from a study of natural mountain ecosystems,and of their continuously changing human societies, may providethe data necessary for an understanding of Tropical MountainEcosystems. Data should provide the necessary inputs for thedevelopment of policies that provide equilibrium between natureand human needs and avoid irreversible damage to mountain


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Figure 4: Different levels of production and their related flows ofsubstances and energy, rom natural ecosystems (withoutman) to disintegrated agricultural systems (totally accul-turated landscapes). (Modified from WINIGER, M., 1983)

NATURAL ADAPTED COMPROM ISEECOSY STEM AGRICULTURAL AGRICULTURAL

SYSTEM SYSTEM

natursl stability natural st.bility natural stabilityanthropogenically significantlymodified m i f i c d ienerpy,

fertiliser)productivi ty productivity productivitylow low to hiqh medium to very

(depending on high (depending oninterna1 energy excernal energyinput) input)

D l S I NTEGRATEDAGRICULTURALSYSTEM

natural stabilitymechanisms mainlyelirninated

productivitymedium CO veryhigh (extrnalenergy input)

fncreasinp human impactIncreasing cxternal enerqy inputIncreasing degree of dependency- ncreasing spatial integration

s S u b s t r a t u m C C o n s u m p t i o n b C o n s t a n t s o l a r an d8 B i o m a s s 1 E x t e r n a l e n e r g y i n p u t a t m o s p h e r i c i n p u tP P r o d u c t i o n P o r ti o n of b i o m a s s0 D e c o m p o s i t i o n a v a i l a b l e a s y i e l d


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ecosystems. This is the objective of the Program on TropicalMountain Ecoeystems of the Decade of the Tropics.SECTION I I - S T A B L U T Y : P R W UThe program on Tropical Mountain Ecosystems, in spite ofthe fascination of the many interesting problerns that itpresents, must have a central, concrete and unifying se% ofpriorities of both practical and theoretical importance, thatwill be of interest to both the scientific community and totropical countries that have concrete and pressing food prob-lems, environmental impacts, and/or demographic pressures, in

their mountains.The following suggestions take into consideration therecomendations made during the last session of the Meridameeting that this program demonstrate that the basic knowledge

of ecology, physiology, genetics, biogeography, anthropology,etc., can make fundamental and tangible contributions to themanagement and development of tropical mountains. This, then,is our principal challenge.The original objective sucii as was determined in Barcelonais: "to gain an understanding of tropical mountain ecosystemsand the interrelationships of the natural ecosystems withprevailing patterns of land use... To identify and validategeneral principles particularly those that might be useful ingaining scientific support to developmental programs andassociated technologies." We propose that within these objec-tives be chosen and that other therne~ econsidered as Pronrams of s u o ~ o r t nd extension of this centraltheme. The theme must be one that focuses on basic conceptsand that the approach be to answer practical questions relatedto the conditions and possibilities of use of tropical moun-tains. At the same time these themes will permit the integra-tion of the results of al1 the proposed studies into a globalvision, capable of producing quantitative, descriptive, and

predictive models.Of the four topics that were proposed and discussed in theMerida meeting, i.e. (1) transects; (2) productive processes;(3) mechanisms of regulation; and (4) stability, we tiiink thatit is this last that provides the unifying base to become thecentral theme, while at the same time incorporating the ele-ments most directly related with this theme from the othertopics. Consequently, we suggest that stability be the basis of


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the definitive program and we now would like to present a fewsuggestions on how to do it and indicate the type of problemthat should be exglored.Core Methodoloaical Princi~les

In oder to delimit the field of research as well as themethodology we will start from the following premises:1. A common experimsntal desim at the different sites.

The focus of the program would be the establishment of anumber of experimental sites where the evolution of a series ofparameters relating to the functioning and structure of pri-mary, secondary and agricultural ecosystems could be studied.A common design would ensure the comparability of the resultsand could include as well unique axgesiments at each site.This would be in accordance with the philosophy adopted byother Decade of the Tropics programs, such as the Tropical Soi1Biology and Fertility and the Program of Responses of Savannasto Stress and Disturbance.2. Verticalitv as the principal characteristics of mountainecosvstems,

The principal characteristics of tropical mountain ecosys-tems is of course the altitudinal gradient, which serves as afirst integrating component of a variety of environmentalfactors. The experimental design will start from the consider-ation of verticaiity, separating the principal altitudinallevels necessary for an understanding of the diversity of theecosystems and types of land use along such a gradient.Horizontal variation, as well as geological, geomorphological,and topological factors will be introduced into the experimen-ta1 design as a function of their local importance and Ourability to multiply the experimental sites.3. The mountah slo~e s a uniaua characteristic of mountains.

From a strictly geomorphological point of view, as well asin terms of the habitats offered and the possibilities of use,mountains @an be divided into two principal systems: valleysand slopes. The majority of the human population is usuallyconcentrated in the valleys due to the better ecologicalconditions offered: better soils, more favorable grades,possibilities for irrigation, better communications, etc. Theslopes instead, even though they can represent up to 95% of the


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available land surface in a mountain system offer less favor-able conditions for human settlement, and are also more suscep-tible to human modification. Even though slopes and valleysform an interrelated system - the watershed - the ecologicaland socioeconomic problems of these two types of environmentare so different that by necessity they must be consideredseparately. Until now most research efforts have been concen-trated in the valleys, primarily on account of the possibili-ties they offertfor ntensified activities with lower ecologi-cal risks. Nevertheless we propose that Our program consideras first priority, if not exclusively, the slopes, since theyare the most difficult to study, the most problematic, the mostextreme and the most crucial for the stability of the system.4. The ~easant s fundamental aaent in the mountain societv.

If we wish to understand the history as well as thepresent situation of the natural and social environment oftropical mountains we must consider the role of the peasant.We identify the peasant as the principal agent that creates andmanages the natural and biological environment according to hisculture, his traditions, and his technology. Especially thepeasant that works his own or rented productive unit with thealmost exclusive work of the family unit forms the basis of thesocial system. Other social agents exist and will be consid-ered by us, but the geasantry will be the focus and object ofOur study5. How to work with the ~easant.

We propose that most of the experimental and observationalwork on ecosystems and natural processes be performed in the'interior of the small peasant farms. Studies at experimentalstations and in natural reserves can complement this work, butthe most important aspect is to follow the ecosystems under thetype of use that the peasant has traditionallp employed,including his working methods, motivations and objectives.That is, the work will be performed in the farms following thealternative uses of the producers, or at most, when convenient,suggesting the introduction of soft technologies.6. Interdisciplinaru Pronram.

The problems that will be addressed in relation to tropi-cal mountain ecosystems and their interrelationships withpresent and potential use are by their very nature multidisci-plinary and their understanding requires a systematic interdis-


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ciplinary approach. Even though this prograna is sponsored byIUBS, and is centered on an ecological and biological approach,it will be essential that other experts not included, espe-cially agronomists, geographers, and specialists in human andenvironmental sciences. We therefore identify the need toestablish immediate contacts with national institutions ofapplied sasearch in agronomy, forestry, planing and use ofnatural reaources, etc. in order to involve thess institutionsdirectly in the development of the program. We also suggestthe convenienca of involving international scientific organiza-tions such as The International Geographical Union (IGU),through its commission on mountain geography; th e InternationalCenter for Tropical Agronomic Research and Teaching (CATIE) inTurrialba, Costa Rica; the International Mountain Society(IMS), and others.7. Altitudina1 zones.

In spite of an apparent great diversity in the peasanteconomies of the slopes of tropical mountains, they can begrouged into a few basic systems that repeat themselves in al1the tropical zones where similar conditions are fotand. Webelieve that a simple altitudinal zonation should be estab-lished compatible with prevailing biological divessity, andthat these zones should be considered as the basic types orzones of production and resource use. An initial workingclassification could be the following:(a ) Lower montane (warm) zone. Ignoring for the moment theecotone piedmont zone, the first typically mountainous zone ischaracterized by its ecological and biological affinities withthe mega th em ic tropical environment, characterized by its highbiological diversity, structural complexity, and high produc-tive potential. This is the only zone where there are pesennialcrops such as sugar cane, bananas and other fruit crops,coffee, tea, cocoa, etc. Among annual crops there is also adominance of tropical or subtropical species such as maize,present in al1 continents, other ceraals or tubers, accordingto continent (rice in Asia, sorghum in Afshca). The upper limitof this ecological and agroecological zone sscillates accordingto local conditions by a few hundred meters around the 2000 mline. We propose that in this zone two agroecosystems bestudied: mahze, as an axample of a seasonal crop, and coffee ortea, as the more typical case of a permanent crop.(b ) Middle mantane (cool) zona. This is the zone where montaneforasts, pastures, and annual crops of temperate zones predom-


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Tropical Mountain Ecossystem UNESCO