Tropische bossen worden misleidend bestempeld als de “longen” van de planeet. Naamgeving is immers een privilege weggelegd voor de dominante soort van de Aarde, die zich maar wat graag als de referentie beschouwd. Bossen leggen namelijk net koolstofdioxide (CO₂) vast en produceren daarbij zuurstof (O₂), terwijl longen juist het tegenovergestelde doen. En toch biedt de vergelijking met vitale organen, de menselijke arrogantie even terzijde, een kader om bossen beter te begrijpen. Net zoals mensen afhankelijk zijn van voedingsstoffen, water en klimaat voor hun groei en ontwikkeling, zo zijn ook bossen afhankelijk van hun omgeving. Om in te schatten hoe bossen zullen omgaan met klimaatsverandering en de verwachte verhoogde CO₂ concentraties is er dringend nood aan een soort “voedseldriehoek” voor bossen. Zullen bomen een sterkere groei vertonen door de grotere atmosferische CO₂-concentraties of zullen ze gelimiteerd worden door andere factoren in hun omgeving? Om hierop een antwoord te vinden trok ik samen met een team studenten en vrijwilligers tot diep in het “hart” van de tropische bossen van het Andesgebergte van Ecuador.
Tropische bossen staan in voor 55% van de boskoolstofopslag (bos-C-opslag), maar worden wereldwijd bedreigd. Ecuador bijvoorbeeld heeft de tweede hoogste graad van ontbossing binnen Zuid-Amerika met een jaarlijks verlies van 0.6% bos. Het alarmerende tempo waarin tropisch bos verdwijnt in combinatie met het beperkte inzicht in het functioneren van deze ecosystemen dwingen ons tot meer onderzoek. Binnen het beperkte onderzoek rond tropische bossen ligt de focus voornamelijk op laaglandbossen zoals het Amazonewoud, terwijl gebergtebossen zowel letterlijk als figuurlijk in nevel verhuld blijven. Een even belangrijke motivatie om te focussen op het Andesgebergte zijn de uitgesproken hoogteverschillen van de bossen. Een hoogtegradiënt is immers een ideaal openlucht-laboratorium om op natuurlijke wijze de invloed van de omgeving te achterhalen. Meer specifiek om de rol van voedingstoffen (“nutriënten” in de plantenwereld) zoals stikstof (N) en fosfor (P) in tropische bossen te bepalen.
Wanneer je een berg beklimt word je geconfronteerd met graduele veranderingen in de vegetatie. Niet alleen worden de bomen kleiner, meer gedrongen en al maar meer overdekt door mossen, maar ook de soortensamenstelling past zich aan. Het is de shift in omgevingscondities die een gelijkaardige shift in plantengemeenschappen triggert met soorten die zijn aangepast aan de condities op een bepaalde hoogteligging. De belangrijkste verandering op grotere hoogte is de lagere temperatuur, die ervoor zorgt dat afbraakprocessen vertragen waardoor de nutriënten in afgevallen bladeren en ander organisch materiaal langzamer worden vrijgesteld. Hierdoor ontstaat er een opstapeling van de nutriënten op de bosbodem, die onbeschikbaar zijn voor plantengroei. Behalve de temperatuur zijn er natuurlijk ook andere factoren die de nutriëntenvoorraad kunnen beïnvloeden zoals de inkomende UV-straling, nevel, etc.
We verwachtten dus dat met stijgende hoogte de hoeveelheid aan planten-beschikbare nutriënten daalt en dat bomen als respons meer gaan investeren in de wortels ten koste van de bovengrondse delen zoals de stam, takken en bladeren. Bomen moeten immers een groter volume bodem doorzoeken om de nodige hoeveelheid nutriënten te verzamelen die de “voedseldriehoek” ze voorschrijft. Bomen worden echter niet enkel gelimiteerd door nutriënten, ook water, licht, etc. kunnen limiterend werken. Onze hypothese was dat er een daling is in de bovengrondse koolstofopslag met stijgende hoogte en dat deze daling te wijten is aan een shift van licht- naar nutriëntenlimitatie met stijgende hoogte. Als bomen weinig licht krijgen, investeren ze sterk in stam, takken en bladeren om het licht optimaal te benutten voor fotosynthese terwijl bij nutriëntenlimitatie bomen eerder zullen investeren in wortelontwikkeling.
Onze resultaten stonden echter lijnrecht tegenover onze vooropgestelde hypothese: De hoogste en laagste bovengrondse koolstofopslag waren immers te vinden op de respectievelijk hoogste en laagste hoogteliggingen. In een eerste poging om dit onverwachte resultaat te verklaren, bogen we ons over de experimentele setup van ons onderzoek. Enerzijds werd de bovengrondse koolstofopslag ingeschat met behulp van bestaande empirische relaties die de biomassa van bomen linken aan diameter-, hoogte- en houtdensiteitmetingen. Op die manier konden we op een relatief eenvoudige manier een inschatting maken van de bovengrondse biomassa, maar blijven we onwetend over de fout op onze inschattingen. Anderzijds worden deze gebergtebossen gekenmerkt door een uitgesproken dynamiek te wijten aan erosie en windval die binnen een relatief klein gebied aanleiding kan geven tot aanzienlijke verschillen in bosontwikkeling en koolstofopslag.
Deze onzekerheden zijn echter onvoldoende om de relatief grote verschillen in bovengrondse koolstofopslag te verklaren. Daarvoor moesten we op zoek naar een dieperliggende oorzaak, zoals de nutriëntenconcentraties van de bodem. De belangrijkste nutriënten binnenin het bosecosysteem zijn stikstof en fosfor, die samen met koolstof in vaste verhoudingen worden opgenomen door bomen. Een belangrijke vaststelling was de shift in nutriëntenlimitatie van fosfor-limitatie naar stikstof-limitatie met stijgende hoogte, te wijten aan de verschillende oorsprong en gedrag van stikstof en fosfor. De hoge temperaturen in het laaglandbos promoten stikstofmineralisatie, waardoor meer stikstof wordt vrijgesteld voor plantengroei. Daarenboven zijn de bodems typisch ouder in laaglandbos waardoor de accumulatie van stikstof via atmosferische depositie verder gevorderd is. Daartegenover staan de jongere bodems van het gebergtebos, die hun beperkte ouderdom te danken hebben aan landverschuivingen en vulkanisme. Doordat fosfor almaar minder beschikbaar wordt voor planten doorheen de tijd, vinden we in deze relatieve jonge bodems grotere hoeveelheden aan planten-beschikbare fosfor terug. Samengevat, lijkt de hoge planten-beschikbaarheid van fosfor op grotere hoogte een belangrijke rol te spelen in de bovengrondse koolstofopslag van deze tropische bossen.
De verwachte temperatuurstijging zal de afbraak van organisch materiaal versnellen en daarenboven zullen ontbossingen en veeteelt aanleiding geven tot verhoogde CO₂-uitstoot en verhoogde atmosferische depositie. Inzicht in de nutriëntendynamiek van tropische bossen is daarom onmisbaar om de toekomst van deze fragiele ecosystemen in te schatten. Daarnaast geven onze resultaten aan dat er een mogelijke onderschatting is van de koolstofopslag in tropische gebergtebossen. Herbebossingen van verwaarloosde gebergtegraslanden kunnen daarom een belangrijke bijdrage leveren in de mitigatie van klimaatsverandering via koolstofopslag en tegelijkertijd lokale boeren van een duurzaam inkomen voorzien. Voldoende argumenten om in te zetten op een integrale bescherming van natuurlijke bossen, oprichting van diverse herbebossingsprojecten en onderzoek dat beiden combineert.
Adamek, M., Corre, M.D. & Hölscher, D., 2009. Early effect of elevated nitrogen input on above-ground net primary production of a lower montane rain forest, Panama. Journal of Tropical Ecology, 25(06), p.637.
Aguirre, N. et al., 2011. Reforestation and Natural Succession as Tools for Restoration on Abandoned Pastures in the Andes of South Ecuador. In Silviculture in the Tropics. pp. 513–524. Available at: <Go to ISI>://BCI:BCI201100612767.
Aiba, S.I. & Kitayama, K., 1999. Structure, composition and species diversity in an altitude-substrate matrix of rain forest tree communities on Mount Kinabalu, Borneo. Plant Ecology, 140(2), pp.139–157.
Aldrich, M. et al., 1997. Tropical montane cloud forests: an urgent priority for conservation. Notes, 2(2), p.17. Available at: http://www.unep-wcmc-apps.org/resources/publications/bulletin_2/text.htm.
Alves, L.F. et al., 2010. Forest structure and live aboveground biomass variation along an elevational gradient of tropical Atlantic moist forest (Brazil). Forest Ecology and Management, 260(5), pp.679–691.
Amundson, R., 2003. Global patterns of the isotopic composition of soil and plant nitrogen. Global Biogeochemical Cycles, 17(1), pp.1031–42. Available at: http://www.agu.org/pubs/crossref/2003/2002GB001903.shtml.
Aragão, L.E.O.C. et al., 2009. Above- and below-ground net primary productivity across ten Amazonian forests on contrasting soils. Biogeosciences Discussions, 6(1), pp.2441–2488.
Arnold, J., Corre, M.D. & Veldkamp, E., 2009. Soil N cycling in old-growth forests across an Andosol toposequence in Ecuador. Forest Ecology and Management, 257(10), pp.2079–2087.
Ashton, P.S., 2003. Floristic zonation of tree communities on wet tropical mountains revisited. Perspectives in Plant Ecology, Evolution and Systematics, 6(1–2), pp.87–104. Available at: http://www.sciencedirect.com/science/article/pii/S1433831904700694.
Baez, S. et al., 2015. Large-scale patterns of turnover and basal area change in Andean forests. PLoS ONE, 10(5), pp.1–14. Available at: http://dx.doi.org/10.1371/journal.pone.0126594.
Baisden, W.T. et al., 2002. A multiisotope C and N modeling analysis of soil organic matter turnover and transport as a function of soil depth in a California annual grassland soil chronosequence. Global Biogeochemical Cycles, 16(4), pp.82–1. Available at: http://pubs.er.usgs.gov/publication/70023833.
Baker, T.R. et al., 2004. Variation in wood density determines spatial patterns in Amazonian forest biomass. Global Change Biology, 10(5), pp.545–562. Available at: <Go to ISI>://000221421600003.
Banin, L. et al., 2012. What controls tropical forest architecture? Testing environmental, structural and floristic drivers. Global Ecology and Biogeography, 21(12), pp.1179–1190.
Baraloto, C. et al., 2011. Disentangling stand and environmental correlates of aboveground biomass in Amazonian forests. Global Change Biology, 17(8), pp.2677–2688.
Barron, A.R., Purves, D.W. & Hedin, L.O., 2011. Facultative nitrogen fixation by canopy legumes in a lowland tropical forest. Oecologia, 165(2), pp.511–520.
Bates, D. & Watts, D., 1988. Nonlinear regression analysis and its applications. orton.catie.ac.cr. Available at: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&do…\nhttp://orton.catie.ac.cr/cgi-bin/wxis.exe/?IsisScript=SIBE01.xis&method….
Bauters, M., 2013. Quantification of the potential carbon capture of reforested highlands in the Andes Thesis. Ugent Faculty of Bio-science engineering.
Becker, R.A., Chambers, J.M. & Wilks, A.R., 1988. The New S Language, Available at: http://adsabs.harvard.edu/abs/1988nsl..book.....B.
Beets, P.N. et al., 2012. Allometric equations for estimating carbon stocks in natural forest in New Zealand. Forests, 3(3), pp.818–839.
Bendix, J. et al., 2006. Cloud occurrence and cloud properties in Ecuador. Climate Research, 30(2), pp.133–147.
Bendix, J. et al., 2006. Seasonality of weather and tree phenology in a tropical evergreen mountain rain forest. International Journal of Biometeorology, 50(6), pp.370–384.
Bergmann, 1993. Ernahrungsstorungen bei Kulturpflanze. , Gustav Fis.
Bernacchi, C.J. et al., 2002. Temperature Response of Mesophyll Conductance. Implications for the Determination of Rubisco Enzyme Kinetics and for Limitations to Photosynthesis in Vivo. Plant Physiology, 130(4), pp.1992–1998. Available at: http://www.plantphysiol.org/content/130/4/1992.abstract\nhttp://www.plantphysiol.org/content/130/4/1992.full.pdf.
Berry, Z.C. & Smith, W.K., 2012. Cloud pattern and water relations in Picea rubens and Abies fraseri, southern Appalachian Mountains, USA. Agricultural and Forest Meteorology, 162-163, pp.27–34.
Bieleski, R.L., 1973. Phosphate pools, phosphate transport, and phosphate availability. Annual review of plant physiology, 24(1), pp.225–252.
Boeckx, P. et al., 2005. Soil δ 15 N patterns in old-growth forests of southern Chile as integrator for N-cycling. Isotopes in Environmental and Health Studies, 41(3), pp.249–259.
Boy, J. et al., 2008. Amazonian biomass burning-derived acid and nutrient deposition in the north Andean montane forest of Ecuador. Global Biogeochemical Cycles, 22(4).
Brandbyge, J. & Holm Nielsen, L.B., 1986. Reforestation of the high Andes with local species. Reports from the Botanical Institute, University of Aarhus, No. 13, p.114 pp.
Van Breugel, M. et al., 2011. Estimating carbon stock in secondary forests: Decisions and uncertainties associated with allometric biomass models. Forest Ecology and Management, 262(8), pp.1648–1657. Available at: http://dx.doi.org/10.1016/j.foreco.2011.07.018.
Brienen, R.J.W. et al., 2015. Long-term decline of the Amazon carbon sink. Nature, 519(7543), pp.344–348. Available at: http://dx.doi.org/10.1038/nature14283.
Brown, S., 1997. Estimating biomass and biomass change of tropical forests: a primer, Available at: http://www.fao.org/docrep/W4095E/W4095E00.htm.
Brown, S., Gillespie, A. & Lugo, A., 1989. Biomass estimation methods for tropical forests with applications to forest inventory data. Forest science, 35(4), pp.881–902. Available at: http://www.ingentaconnect.com/content/saf/fs/1989/00000035/00000004/art….
Brown, S. & Lugo, a, 1982. The storage and production of organic matter in tropical forests and their role in the global carbon cycle. Biotropica, 14, pp.161–187.
Brown, S. & Lugo, A.E., 1982. The Storage and Production of Organic Matter in Tropical Forests and Their Role in the Global Carbon Cycle. Biotropica, 14(3), pp.161–187. Available at: http://www.jstor.org/stable/2388024\nhttp://www.jstor.org.proxy.library.cornell.edu/stable/pdfplus/2388024.p….
Bruijnzeel, A.L.A. et al., 2013. Climatic Conditions and Tropical Montane Forest Productivity : The Fog Has Not Lifted Yet CLIMATIC CONDITIONS AND TROPICAL MONTANE FOREST PRODUCTIVITY : THE FOG HAS NOT LIFTED YET. , 79(1), pp.3–9.
Bruijnzeel, L., 2001. Hydrology of tropical montane cloud forests: a reassessment. Land use and water resources research, 1, pp.1–18. Available at: http://scholar.google.com/scholar?hl=en&btnG=Search&q=intitle:Hydrology…\nhttp://www.bvsde.paho.org/bvsacd/cd56/hydrology/cap3-4.pdf.
Bruijnzeel, L. a. & Veneklaas, E.J., 1998. Climatic conditions and tropical montane forest productivity: The fog has not lifted yet. Ecology, 79(1), pp.3–9.
Bruijnzeel, L.A. et al., 1993. Hydrological Observations in Montane Rain Forests on Gunung Silam, Sabah, Malaysia, with Special Reference to thèMassenerhebung’ Effect. Journal of Ecology, 81(1), pp.145–167. Available at: http://www.jstor.org/stable/2261231\nhttp://www.jstor.org/page/info/about/policies/terms.jsp.
Bruijnzeel, L.A., 1989. Nutrient content of bulk precipitation in south central Java, Indonesia. , Journal of.
Bruijnzeel, L.A., 2010. TMCF: State of knowledge and sustainability perspectives in an changing world.
Bruijnzeel, L.A. & Hamilton, L.S., 2000. DECISION TIME FOR CLOUD FORESTS,
Bruijnzeel, L.A., Mulligan, M. & Scatena, F.N., 2011. Hydrometeorology of tropical montane cloud forests: Emerging patterns. Hydrological Processes, 25(3), pp.465–498.
Bruijnzeel, F. N. Scatena, L.S.H., 2011. Tropical Montane Cloud Forests: Science for Conservation and Management C. U. Press, ed.,
Bubb, P. et al., 2004. Cloud forest agenda, Available at: http://sea-swift.unep-wcmc.org/resources/publications/UNEP_WCMC_bio_ser….
Buchkowski, R.W., Schmitz, O.J. & Bradford, M.A., 2015. Microbial stoichiometry overrides biomass as a regulator of soil carbon and nitrogen cycling. Ecology, 96(4), pp.1139–1149.
Buytaert, W.; Duyck, H.; Dercon, G.; Deckers, J.; Wyseure, G., 2003. The interaction between parent material, climate and volcanism as the major soil forming factor in the Ecuadorian high Andes regio.
Buytaert, W., Deckers, J. & Wyseure, G., 2007. Regional variability of volcanic ash soils in south Ecuador: The relation with parent material, climate and land use. Catena, 70(2), pp.143–154.
Callesen, I. et al., 2013. The natural abundance of 15N in litter and soil profiles under six temperate tree species: N cycling depends on tree species traits and site fertility. Plant and Soil, 368(1-2), pp.375–392.
Cardelús, C.L. & Mack, M.C., 2010. The nutrient status of epiphytes and their host trees along an elevational gradient in Costa Rica. Plant Ecology, 207(1), pp.25–37.
Cavelier, J., 1995. Reforestation with the native tree Alnus acuminata: effects on phytodiversity and species richness in an upper montane rain forest area of Colombia. In Tropical montane cloud forests. pp. 125–137.
Cernusak, L.A. et al., 2008. Conifers , Angiosperm Trees , and Lianas : Growth , Whole-Plant Water and Nitrogen Use Efficiency , and Stable Isotope Composition ( d 13 C and d 18 O ) of Seedlings Grown in a Tropical Environment 1 [ W ][ OA ]. Plant Physiology, 148(September), pp.642–659.
Cernusak, L.A. et al., 2013. Tropical forest responses to increasing atmospheric CO2: Current knowledge and opportunities for future research. Functional Plant Biology, 40(6), pp.531–551.
Chambers, J.Q. et al., 2000. Decomposition and carbon cycling of dead trees in tropical forests of the central Amazon. Oecologia, 122(3), pp.380–388.
Chamorro, G.C. et al., 2012. ESTIMACIÓN DE LA BIOMASA AÉREA Y CAPTURA DE CARBONO EN ÁRBOLES DISPERSOS EN POTREROS CON MOTILÓN SILVESTRE (Freziera canescens) EN EL MUNICIPIO DE PASTO NARIÑO-COLOMBIA. Revista de Ciencias Agrícolas, 24(1 y 2), pp.46–55.
Chao, L. & Teri C. Balser, 2010. Microbial production of recalcitrant organic matter in global soils: implications for productivity and climate policy. Nature Rev. Microbiol. 8, 593–599.
Chapin, F.S., Schulze, E. & Mooney, H. a, 1990. The Ecology and Economics of Storage in Plants. Annual Review of Ecology and Systematics, 21(1), pp.423–447.
Chave, J. et al., 2014. Improved allometric models to estimate the aboveground biomass of tropical trees. Global Change Biology, 20(10), pp.3177–3190.
Chave, J. et al., 2006. Regional and phylogenetic variation of wood density across 2456 neotropical tree species. Ecological Applications, 16(6), pp.2356–2367.
Chave, J. et al., 2009. Regional and temporal patterns of litterfall in tropical South America. Biogeosciences Discussions, 6, pp.7565–7597.
Chave, J. et al., 2005. Tree allometry and improved estimation of carbon stocks and balance in tropical forests. Oecologia, 145, pp.87–99. Available at: http://www.springerlink.com/content/p1k67p2175l56365/.
Choi, W.-J. et al., 2005. Irrigation and fertilization effects on foliar and soil carbon and nitrogen isotope ratios in a loblolly pine stand. Forest Ecology and Management, 213(1-3), pp.90–101. Available at: http://www.sciencedirect.com/science/article/pii/S0378112705002203.
Ciais, P. et al., 2013. Carbon and Other Biogeochemical Cycles. In Climate Change 2013 - The Physical Science Basis. pp. 465–570. Available at: http://www.ipcc.ch/report/ar5/wg1/docs/review/WG1AR5_SOD_Ch06_All_Final…\nhttp://ebooks.cambridge.org/ref/id/CBO9781107415324A023.
Clark, D. a, 2004. Sources or sinks? The responses of tropical forests to current and future climate and atmospheric composition. Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 359(1443), pp.477–491.
Clark, D.A. et al., 2001. Measuring net primary production in forests: Concepts and field methods. Ecological Applications, 11(2), pp.356–370.
Clark, D.A., Clark, D.B. & Oberbauer, S.F., 2013. Field-quantified responses of tropical rainforest aboveground productivity to increasing CO2 and climatic stress, 1997-2009. Journal of Geophysical Research: Biogeosciences, 118(2), pp.783–794.
Clark, D.B., Hurtado, J. & Saatchi, S.S., 2015. Tropical rain forest structure, tree growth and dynamics along a 2700-m elevational transect in Costa Rica. PLoS ONE, 10(4).
Clark, D.B. & Kellner, J.R., 2012. Tropical forest biomass estimation and the fallacy of misplaced concreteness. Journal of Vegetation Science, 23(6), pp.1191–1196.
Cleveland, C.C. et al., 2011a. Relationships among net primary productivity, nutrients and climate in tropical rain forest: A pan-tropical analysis. Ecology Letters, 14(9), pp.939–947.
Cleveland, C.C. et al., 2011b. Relationships among net primary productivity, nutrients and climate in tropical rain forest: A pan-tropical analysis. Ecology Letters, 14(9), pp.939–947.
Cleveland, C.C. et al., 2004. Soil microbial dynamics in Costa Rica: seasonal and biogeochemical constraints. Biotropica, 36(2), pp.184–195. Available at: http://onlinelibrary.wiley.com/doi/10.1111/j.1744-7429.2004.tb00311.x/a….
Cleveland, W.S., 1981. LOWESS: A program for smoothing scatterplots by robust locally weighted regression. American Statistician, 35(1), p.54. Available at: http://www.jstor.org/stable/2683591.
Cleveland, W.S., 1979. Robust Locally Weighted Regression and Smoothing Scatterplots. Journal of the American Statistical Association, 74(368), pp.829–836. Available at: http://www.jstor.org/stable/2286407.
Condesan, 2013. Monitoreo de contenidos y flujos de carbono en gradientes altudinales altoandinos. , p.55. Available at: http://www.cooperacionsuizaenperu.org.pe/cosude-proyectos/proyectos-pro….
Connin, S.L., Feng, X. & Virginia, R.A., 2001. Isotopic discrimination during long-term decomposition in an arid land ecosystem. Soil Biology and Biochemistry, 33(1), pp.41–51.
Couteaux, M.M., Bottner, P. & Berg, B., 1995. Litter decomposition climate and litter quality. Trends in Ecology and Evolution, 10(2), pp.63–66.
Craine, J.M. et al., 2015. Convergence of soil nitrogen isotopes across global climate gradients. Scientific Reports, 5, p.8280. Available at: http://www.nature.com/doifinder/10.1038/srep08280.
Craine, J.M. et al., 2015. Ecological interpretations of nitrogen isotope ratios of terrestrial plants and soils. Plant Soil, 396, pp.1–26.
Craine, J.M. et al., 2009. Global patterns of foliar nitrogen isotopes and their relationships with climate, mycorrhizal fungi, foliar nutrient concentrations, and nitrogen availability. New Phytologist, 183(4), pp.980–992.
Culmsee, H. et al., 2010. Forest aboveground biomass along an elevational transect in Sulawesi, Indonesia, and the role of Fagaceae in tropical montane rain forests. Journal of Biogeography, 37(5), pp.960–974.
Davidson, E. a et al., 2007. Recuperation of nitrogen cycling in Amazonian forests following agricultural abandonment. Nature, 447(7147), pp.995–998.
Delaney, M. et al., 1998. The Quantity and Turnover of Dead Wood in Permanent Forest Plots in Six Life Zones of Venezuela1. Biotropica, 30(1), pp.2–11. Available at: http://dx.doi.org/10.1111/j.1744-7429.1998.tb00364.x\nhttp://onlinelibrary.wiley.com/store/10.1111/j.1744-7429.1998.tb00364.x….
Delwiche, C.C. & Steyn, P.L., 1970. Nitrogen isotope fractionation in soils and microbial reactions. Environmental Science & Technology, 4(11), pp.929–935. Available at: http://pubs.acs.org/doi/abs/10.1021/es60046a004.
Demol, M., 2016. Functional diversity in natural forests along an altitudinal gradient in Northern Ecuador.
DeWalt, S.J. & Chave, J., 2004. Structure and Biomass of Four Lowland Neotropical Forests. Biotropica, 36(1), pp.7–19. Available at: http://onlinelibrary.wiley.com/doi/10.1111/j.1744-7429.2004.tb00291.x/a…\nhttp://onlinelibrary.wiley.com/store/10.1111/j.1744-7429.2004.tb00291.x….
Dieleman, W.I.J. et al., 2013. Soil carbon stocks vary predictably with altitude in tropical forests: Implications for soil carbon storage. Geoderma, 204-205, pp.59–67.
Dieter, D., Elsenbeer, H. & Turner, B.L., 2010. Phosphorus fractionation in lowland tropical rainforest soils in central Panama. Catena, 82(2), pp.118–125.
Dijkstra, P. et al., 2008. 15N enrichment as an integrator of the effects of C and N on microbial metabolism and ecosystem function. Ecology Letters, 11(4), pp.389–397. Available at: http://doi.wiley.com/10.1111/j.1461-0248.2008.01154.x [Accessed May 11, 2016].
Dixon, R.K. et al., 1994. Carbon Pools and Flux of Global Forest Ecosystems. Science, 263, pp.185–190.
Dodson, C.H. & Gentry, A.H., 1991. Biological Extinction in Western Ecuador. Annals of the Missouri Botanical Garden, 78(2), pp.273–295. Available at: http://www.jstor.org/stable/2399563?origin=crossref.
Drechsel, P. & Zech, W., 1991. Foliar nutrient levels of broad-leaved tropical trees. , Plant and .
Edwards, P.J., 1982. Studies of Mineral Cycling in a Montane Rain Forest in New Guinea: V. Rates of Cycling in STUDIES OF MINERAL CYCLING IN A MONTANE RAIN FOREST IN NEW GUINEA V. RATES OF CYCLING IN THROUGHFALL AND LITTER FALL. Journal of Ecology, 70(70), pp.807–827. Available at: http://www.jstor.org/stable/2260106 [Accessed April 12, 2016].
Edwards, P.J. & Grubb, P.J., 1982. Studies of Mineral Cycling in a Montane Rain Forest in New Guinea: IV. Soil Characteristics and the Division of Mineral Elements between the Vegetation and Soil. British Ecological Society, 70(2), pp.649–666. Available at: http://www.jstor.org/stable/info/2259929.
Eller, C.B., Lima, A.L. & Oliveira, R.S., 2013. Foliar uptake of fog water and transport belowground alleviates drought effects in the cloud forest tree species, Drimys brasiliensis (Winteraceae). New Phytologist, 199(1), pp.151–162.
Fabian, P., Kohlpaintner, M. & Rollenbeck, R., 2005. Biomass burning in the Amazon-fertilizer for the mountaineous rain forest in Ecuador. Environmental science and pollution research international, 12(5), pp.290–296.
Falkowski, P.G. et al., 2000. The global carbon cycle: a test of our knowledge of earth as a system. Science, 290(5490), pp.291–296.
FAO, 2015. GLOBAL FOREST RESOURCES ASSESSMENT 2015. Available at: http://www.fao.org/3/a-i4808e.pdf.
FAO, Legacy Soil Maps and Soils Databases. Available at: http://www.fao.org/soils-portal/soil-survey/soil-maps-and-databases/en/ [Accessed March 14, 2016].
FAO (Food and Agriculture Organization, I., 1975. Inventario Forestal del Bosque Nacional Alejandro von Humboldt, Region de Pucallpa, Peru. Limited, Fi. Vancouver, CA., FAO. 34 p. ., FAO (Food.
FAO, 2006. Global Forest Resources Assessment 2005: Progress towards sustainable forest management, Available at: http://www.fao.org/documents/show_cdr.asp?url_file=/DOCREP/004/Y1997E/y…\nwww.fao.org/forestry/site/fra2005/en\nhttp://www.fao.org/forestry/index.jsp.
Farley, K.A., 2007. Grasslands to tree plantations: Forest transition in the Andes of Ecuador. Annals of the Association of American Geographers, 97(4), pp.755–771.
Farquhar, G.D. et al., 1989. Carbon isotope fractionation and plant water-use efficiency. In Stable Isotopes in Ecological Research. pp. 21–40.
Farquhar, G.D. & Sharkey, T.D., 1982. Stomatal Conductance and Photosynthesis. Annual Review of Plant Physiology, 33(1), pp.317–345.
Fehse, J. et al., 2002. High altitude tropical secondary forests: A competitive carbon sink? Forest Ecology and Management, 163(1-3), pp.9–25.
Feldpausch, T.R. et al., 2011. Height-diameter allometry of tropical forest trees. Biogeosciences, 8(5), pp.1081–1106.
Feldpausch, T.R. et al., 2012. Tree height integrated into pantropical forest biomass estimates. Biogeosciences, 9(8), pp.3381–3403.
Fernández-Martínez, M. et al., 2014. Nutrient availability as the key regulator of global forest carbon balance. Nature Climate Change, 4(June), pp.471–476. Available at: http://www.nature.com/nclimate/journal/v4/n6/full/nclimate2177.html.
Ferreri, L., 2015. Suivi de la survie et de la croissance des arbres plantés et issu de régénération naturelle, dans le projet de reforestation avec des espèces natives dans les bassins versants de Pachijal et Mira,
Ferry, B. et al., 2012. Is climate a stronger driver of tree growth than disturbance? A comment on Toledo et al. (2011). Journal of Ecology, 100(5), pp.1065–1068.
Fine, P.V.A. et al., 2013. Insect herbivores, chemical innovation, and the evolution of habitat specialization in Amazonian trees. Ecology, 94(8), pp.1764–1775.
Fisher, J.B. et al., 2013. Nutrient limitation in rainforests and cloud forests along a 3,000-m elevation gradient in the Peruvian Andes. Oecologia, 172(3), pp.889–902. Available at: http://link.springer.com/10.1007/s00442-012-2522-6.
Fleming, 2014. Estimating plant biomass in early-successional subtropical vegetation using a visual obstruction technique.
Flexas, J. et al., 2008. Mesophyll conductance to CO2: Current knowledge and future prospects. Plant, Cell and Environment, 31(5), pp.602–621.
Fogel, R., 1980. Mycorrhizae and nutrient cycling in natural forest ecosystems. New Phytologist, 86(2), pp.199–212. Available at: http://onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.1980.tb03189.x/p….
Foster, N.W. & Bhatti, J.S., 2006. Forest Ecosystems : Nutrient Cycling. Encyclopedia of Soil Science, pp.718–721.
Frahm, J.P. & Gradstein, S.R., 1991. An Altitudinal Zonation of Tropical Rain-Forests Using Byrophytes. Journal of Biogeography, 18(6), pp.669–678. Available at: <Go to ISI>://A1991GT20300008\nhttp://www.jstor.org/stable/pdfplus/2845548.pdf.
Gardi, C., Angelini, M., Barceló, S., Comerma, J., Cruz Gaistardo, C. et al., 2015. Soil Atlas of Latin America and the Caribbean, European Commission, Publications Office of the European Union, L-2995 Luxembourg.
Garreaud, R.D., 2009. Advances in Geosciences The Andes climate and weather. Advances In Geosciences, 7(1), pp.1–9. Available at: http://www.adv-geosci.net/22/3/2009/adgeo-22-3-2009.html\nhttp://www.adv-geosci.net/22/3/2009/adgeo-22-3-2009.pdf.
Giardina, C.P. et al., 2003. Primary production and carbon allocation in relation to nutrient supply in a tropical experimental forest. Global Change Biology, 9(10), pp.1438–1450. Available at: <Go to ISI>://000185841900008.
Gibbs, H.K. et al., 2007. Monitoring and estimating tropical forest carbon stocks: making REDD a reality. Environmental Research Letters, 2(4), p.045023.
Girardin, C. a J. et al., 2010. Net primary productivity allocation and cycling of carbon along a tropical forest elevational transect in the Peruvian Andes. Global Change Biology, 16(12), pp.3176–3192.
Girardin, C. a J., Espejob, J.E.S., et al., 2013. Productivity and carbon allocation in a tropical montane cloud forest in the Peruvian Andes. Plant Ecology & Diversity, 7(1--2), pp.1–17. Available at: http://dx.doi.org/10.1080/17550874.2013.820222.
Girardin, C. a J., Farfan-Rios, W., et al., 2013. Spatial patterns of above-ground structure, biomass and composition in a network of six Andean elevation transects. Plant Ecology & Diversity, 0874(March 2015), pp.1–11. Available at: http://dx.doi.org/10.1080/17550874.2013.820806.
Girardin, C.A.J. et al., 2014. Seasonal production, allocation and cycling of carbon in two mid-elevation tropical montane forest plots in the Peruvian Andes. Plant Ecology & Diversity, 7(1-2), pp.125–142. Available at: http://dx.doi.org/10.1080/17550874.2013.819042\nhttp://www.tandfonline.com/doi/abs/10.1080/17550874.2013.819042#.VI8hpC….
Gleixner, G., 2013. Soil organic matter dynamics: A biological perspective derived from the use of compound-specific isotopes studies. Ecological Research, 28(5), pp.683–695.
Goldsmith, G.R., Matzke, N.J. & Dawson, T.E., 2012. The incidence and implications of clouds for cloud forest plant water relations. Ecology Letters, p.n/a–n/a. Available at: http://onlinelibrary.wiley.com/doi/10.1111/ele.12039/abstract.
Gomez-Peralta, D. et al., 2008. Rainfall and cloud-water interception in tropical montane forests in the eastern Andes of Central Peru. Forest Ecology and Management, 255(3-4), pp.1315–1325.
Goodman, R.C., Phillips, O.L. & Baker, T.R., 2014. The importance of crown dimensions to improve tropical tree biomass estimates. Ecological Applications, 24(4), pp.680–698.
Gotsch, S.G. et al., 2014. Foggy days and dry nights determine crown-level water balance in a seasonal tropical montane cloud forest. Plant, Cell and Environment, 37(1), pp.261–272.
Graefe, S., Hertel, D. & Leuschner, C., 2010. N, P and K limitation of fine root growth along an elevation transect in tropical mountain forests. Acta Oecologica, 36(6), pp.537–542.
Grubb, P.. J.., 1977. Control of Forest Growth and Distribution on Wet Tropical Mountains : With Special Reference to Mineral Nutrition. , 8(1977), pp.83–107.
Grubb, P.J., 1971. Interpretation of the “Massenerhebung” Effect on Tropical Mountains. Nature, 229(5279), pp.44–45. Available at: http://www.nature.com/doifinder/10.1038/229044a0 [Accessed April 12, 2016].
Grubb, P.J. & Whitmore, T.C., 1966. A comparison of montane and lowland rain forest in Ecuador: II. The climate and its effects on the distribution and physiognomy of the forests. Journal of Ecology, 54(2), pp.303–333.
Gunter, S. et al., 2009. Determinants for successful reforestation of abandoned pastures in the Andes: Soil conditions and vegetation cover. Forest Ecology and Management, 258(2), pp.81–91.
Gunter, S. et al., 2007. Influence of distance to forest edges on natural regeneration of abandoned pastures: A case study in the tropical mountain rain forest of Southern Ecuador. European Journal of Forest Research, 126(1), pp.67–75.
Haagen, 2011. Carbon research at Maquipucuna biological reserve. , pp.1–41.
Hall, M.L. et al., 2008. Ecuadorian Andes volcanism: A review of Late Pliocene to present activity. Journal of Volcanology and Geothermal Research, 176(1), pp.1–6.
Hamilton, L., Juvik, J. & Scatena, F.N., 1995. Tropical Montane Cloud Forests,
Harris, N.L., Hall, C.A.S. & Lugo, A.E., 2008. Estimates of species- and ecosystem-level respiration of woody stems along an elevational gradient in the Luquillo Mountains, Puerto Rico. Ecological Modelling, 216(3-4), pp.253–264.
Hart, Stephen C, Stark, J.M., Davidson, E.A., Firestone, M.K., 1994. Nitrogen mineralization, immobilization, and nitrification. Methods of Soil Analysis, Part 2. Microbiological and Biochemical Properties, (5), pp.985–1018.
He, X. et al., 2009. Responses of litter decomposition to temperature along a chronosequence of tropical montane rainforest in a microcosm experiment. Ecological Research, 24(4), pp.781–789.
Hedin, L.O. et al., 2009. The Nitrogen Paradox in Tropical Forest Ecosystems. Annual Review of Ecology Evolution and Systematics, 40, pp.613–635.
Hedin, L.O., Vitousek, P.M. & Matson, P. a, 2003. Nutrient losses over four million years of tropical forest development. Ecology, 84(9), pp.2231–2255. Available at: http://www.esajournals.org/doi/abs/10.1890/02-4066.
Herbert, D. a. & Fownes, J.H., 1995. Phosphorus limitation of forest leaf area and net primary production on a highly weathered soil. Biogeochemistry, 29(3), pp.223–235.
Hessen, D.O. et al., 2004. Carbon sequestration in ecosystems: The role of stoichiometry. Ecology, 85(5), pp.1179–1192.
Hijmans, R.J. et al., 2005. Very high resolution interpolated climate surfaces for global land areas. International Journal of Climatology, 25(15), pp.1965–1978.
Hiremath, A.J. & Ewel, J.J., 2001. Ecosystem nutrient use efficiency, productivity, and nutrient accrual in model tropical communities. Ecosystems, 4(7), pp.669–682.
Hobbie, E.A. & Högberg, P., 2012. Nitrogen isotopes link mycorrhizal fungi and plants to nitrogen dynamics. New Phytologist, 196(2), pp.367–382.
Hofstede, R., Aguirre, N., 1999. Biomasa y dinámica del carbono en relación con las actividades forestales en la Sierra del Ecuador. El Páramo Como Espacio de Mitigación de Carbono Atmos- ferico, Serie Páramo 1, edited by: Medina, G. and Mena, P., Edi- ciones Abya Yala, Quito, 29–51.
Högberg, P. et al., 2011. Recovery of ectomycorrhiza after “nitrogen saturation” of a conifer forest. New Phytologist, 189(2), pp.515–525.
Högberg, P., 1996. Tansley Review No. 95 15N natural abundance in soil-plant systems. Section of Soil Science, Department of Forest Ecology, Swedish University of Agricultural Sciences, S-901 83 Umea, Sweden.
Högberg, P. & Johannisson, C., 1993. 15N Abundance of forests is correlated with losses of nitrogen. Plant and Soil, 157(1), pp.147–150.
Holder, C.D., 2004. Rainfall interception and fog precipitation in a tropical montane cloud forest of Guatemala. Forest Ecology and Management, 190(2-3), pp.373–384.
Homeier, J. et al., 2012. Tropical Andean Forests Are Highly Susceptible to Nutrient Inputs-Rapid Effects of Experimental N and P Addition to an Ecuadorian Montane Forest. PLoS ONE, 7(10).
Hostettler, S., 2002. Tropical montane cloud forests: A challenge for conservation. Bois et Forets des Tropiques, 274(274), pp.19–30. Available at: <Go to ISI>://BIOSIS:PREV200300101202.
Houghton, R.A., 2005. Aboveground forest biomass and the global carbon balance. Global Change Biology, 11(6), pp.945–958.
Hu, S., 1987. Akaike information criterion statistics. Mathematics and Computers in Simulation, 29(5), p.452.
Huang, S., Titus, S.J. & Wiens, D.P., 1992. Comparison of nonlinear height–diameter functions for major Alberta tree species. Canadian Journal of Forest Research, 22, pp.1297–1304.
Ichiro Terashima, Takehiro Masuzawa, Hideaki Ohba, Y.Y., 1995. Is photosynthesis suppressed at higher elevations due to low CO2 pressure. Ecology, Vol. 76, No. 8 (Dec., 1995), pp. 2663-2668.
INAMHI, Servicio meteorologico del Ecuador. Available at: http://www.serviciometeorologico.gob.ec/ [Accessed May 20, 2011].
IPCC, 2014. Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change,
Jankowski, J.E. & Rabenold, K.N., 2007. Endemism and local rarity in birds of neotropical montane rainforest. Biological Conservation, 138(3-4), pp.453–463.
Janos, D.P., 1980. Vesicular-Arbuscular Mycorrhizae Affect Lowland Tropical Rain Forest Plant Growth. Ecology, 61(1), pp.151–162.
Janzen, D.H., 1967. Why Mountain Passes are Higher in the Tropics. The American Naturalist, 101(919), p.233.
Jarvis, A. & Mulligan, M., 2011. The climate of cloud forests. Hydrological Processes, 25(3), pp.327–343.
Johnson, A.H. et al., 2003. Biogeochemical implications of labile phosphorus in forest soils determined by the Hedley fractionation procedure. OECOLOGIA, 135(4), pp.487–499.
Jordan, C.F.F. & Herrera, R., 1981. Tropical rain forests: are nutrients really critical? American Naturalist, 117(2), pp.167–180.
Joseph Wright, S., 2013. The carbon sink in intact tropical forests. Global Change Biology, 19(2), pp.337–339.
Kenzo, T. et al., 2010. Changes in above- and belowground biomass in early successional tropical secondary forests after shifting cultivation in Sarawak, Malaysia. Forest Ecology and Management, 260(5), pp.875–882. Available at: http://www.sciencedirect.com/science/article/pii/S0378112710003294 [Accessed December 26, 2015].
Ketterings, Q.M. et al., 2001. Reducing uncertainty in the use of allometric biomass equations for predicting above-ground tree biomass in mixed secondary forests. Forest Ecology and Management, 146(1-3), pp.199–209.
Killeen, T.J. et al., 2007. Dry spots and wet spots in the Andean hotspot. In Journal of Biogeography. pp. 1357–1373.
Killingbeck, K.T., 1996. Nutrients in senesced leaves: Keys to the search for potential resorption and resorption proficiency. Ecology, 77(6), pp.1716–1727.
Kitayama, K. & Aiba, S.I., 2002. Ecosystem structure and productivity of tropical rain forests along altitudinal gradients with contrasting soil phosphorus pools on Mount Kinabalu, Borneo. Journal of Ecology, 90(1), pp.37–51. Available at: <Go to ISI>://WOS:000174154500004\nhttp://www.jstor.org/stable/pdfplus/3072317.pdf.
Kitayama, K. & Mueller-Dombois, D., 1994. An altitudinal transect analysis of the windward vegetation on Haleakala, a Hawaiian island mountain: (2) vegetation zonation. Phytocoenologia, 24(2), pp.135–154.
Knoke, T. et al., 2009. Can tropical farmers reconcile subsistence needs with forest conservation? Frontiers in Ecology and the Environment, 7(10), pp.548–554.
Koerselman, W. & Meuleman, A.F.M., 1996. The Vegetation N:P Ratio: a New Tool to Detect the Nature of Nutrient Limitation. Journal of Applied Ecology, 33(6), pp.1441–1450. Available at: http://www.jstor.org/stable/2404783.
Körner, C., 2007. The use of “altitude” in ecological research. Trends in Ecology & Evolution, 22(11), pp.569–574. Available at: http://linkinghub.elsevier.com/retrieve/pii/S0169534707002819.
Lal, R., 2005. Forest soils and carbon sequestration. Forest Ecology and Management, 220(1-3), pp.242–258.
Lambers, H. et al., 2008. Plant nutrient-acquisition strategies change with soil age. Trends in Ecology and Evolution, 23(2), pp.95–103.
Laurance, W.F. et al., 1999. Relationship between soils and Amazon forest biomass: A landscape-scale study. Forest Ecology and Management, 118(1-3), pp.127–138.
Letts, M.G. & Mulligan, M., 2005. The impact of light quality and leaf wetness on photosynthesis in north-west Andean tropical montane cloud forest. Journal of Tropical Ecology, 21(5), pp.549–557.
Leuschner, C. et al., 2007. Large altitudinal increase in tree root/shoot ratio in tropical mountain forests of Ecuador. Basic and Applied Ecology, 8(3), pp.219–230.
Lieberman, D. et al., 1996. Tropical forest structure and composition on a large-scale altitudinal gradient in Costa Rica. Journal of Ecology, 84(2), pp.137–152. Available at: <Go to ISI>://A1996UH36300001.
Lovelock, C.E. et al., 2007. Testing the growth rate vs. geochemical hypothesis for latitudinal variation in plant nutrients. Ecology Letters, 10(12), pp.1154–1163.
Lu, A. et al., 2009. On the relationship between latitude and altitude temperature effects. In Proceedings - 2009 International Conference on Environmental Science and Information Application Technology, ESIAT 2009. pp. 55–58.
Magdalena López, Free de Koning, Hugo Paredes, P.B., 2002. Estimación de carbono en biomasa de bosques secundarios y plantacio- nes forestales en el Noroccidente de Ecuador. , p.42.
Makowski Giannoni, S. et al., 2014. Natural or anthropogenic? On the origin of atmospheric sulfate deposition in the Andes of southeastern Ecuador. Atmospheric Chemistry and Physics, 14(20), pp.11297–11312.
Malhi, Y. et al., 2002. An international network to monitor the structure, composition and dynamics of Amazonian forests (RAINFOR). Journal of Vegetation Science, 13, pp.439–450. Available at: http://eprints.whiterose.ac.uk/236/.
Malhi, Y. et al., 2009. Comprehensive assessment of carbon productivity, allocation and storage in three Amazonian forests. Global Change Biology, 15(5), pp.1255–1274.
Malhi, Y. et al., 2010. Introduction: Elevation gradients in the tropics: Laboratories for ecosystem ecology and global change research. Global Change Biology, 16(12), pp.3171–3175.
Malhi, Y. et al., 2004. The above-ground coarse wood productivity of 104 Neotropical forest plots. Global Change Biology, 10(5), pp.563–591.
Malhi, Y. et al., 2006. The regional variation of aboveground live biomass in old-growth Amazonian forests. Global Change Biology, 12(7), pp.1107–1138.
Malhi, Y., Doughty, C. & Galbraith, D., 2011. The allocation of ecosystem net primary productivity in tropical forests. Philosophical Transactions of the Royal Society B: Biological Sciences, 366(1582), pp.3225–3245.
Malhi, Y. & Grace, J., 2000. Tropical forests and atmospheric carbon dioxide. Trends in Ecology & Evolution, 15(8), pp.332–337.
Marrs, R. et al., 1988. Changes in soil nitrogen-mineralization and nitrification along an altitudinal transect in tropical rain forest in Costa Rica. The Journal of Ecology, 76(2), pp.466–482. Available at: http://www.jstor.org/stable/2260606.
Marshall, A.R. et al., 2012. Measuring and modelling above-ground carbon and tree allometry along a tropical elevation gradient. Biological Conservation, 154, pp.20–33.
Marshall, J.D. & Zhang Jianwei, 1994. Carbon isotope discrimination and water-use efficiency in native plants of the north-central Rockies. Ecology, 75(7), pp.1887–1895.
Martinelli, L. a. et al., 1999. Nitrogen stable isotopic composition of leaves and soil: Tropical versus temperate forests. Biogeochemistry, 46(1-3), pp.45–65.
Mascaro, J. et al., 2011. Controls over aboveground forest carbon density on Barro Colorado Island, Panama. Biogeosciences, 8(6), pp.1615–1629.
Matson, A.L. et al., 2015. Free-living nitrogen fixation responds to elevated nutrient inputs in tropical montane forest floor and canopy soils of southern Ecuador. Biogeochemistry, 122(2-3), pp.281–294.
Mayor, J.R., Wright, S.J. & Turner, B.L., 2014. Species-specific responses of foliar nutrients to long-term nitrogen and phosphorus additions in a lowland tropical forest. Journal of Ecology, 102(1), pp.36–44.
McGlynn, T.P. et al., 2007. Phosphorus limits tropical rain forest litter fauna. Biotropica, 39(1), pp.50–53.
McGroddy, M.E., Daufresne, T. & Hedin, L.O., 2004. Scaling of C:N:P stoichiometry in forests worldwide: Implications of terrestrial redfield-type ratios. Ecology, 85(9), pp.2390–2401.
McGuire, K.L. et al., 2010. Slowed decomposition is biotically mediated in an ectomycorrhizal, tropical rain forest. Oecologia, 164(3), pp.785–795.
Ministerio del Ambiente, 2013. Sistema de Classificacion de ecosistemas del Ecuador continental.
Moghaddam, A. et al., 2013. Carbon isotope discrimination and water use efficiency relationships of alfalfa genotypes under irrigated and rain-fed organic farming. European Journal of Agronomy, 50, pp.82–89.
Mooshammer, M. et al., 2014. Adjustment of microbial nitrogen use efficiency to carbon:nitrogen imbalances regulates soil nitrogen cycling. Nature communications, 5, p.3694. Available at: http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=3997803&tool=….
Moser, G. et al., 2008. Altitudinal Changes in Stand Structure and Biomass Allocation of Tropical Mountain Forests in Relation to Microclimate and Soil Chemistry. In Ecological Studies. pp. 229–242. Available at: http://dx.doi.org/10.1007/978-3-540-73526-7_22.
Moser, G. et al., 2011. Elevation effects on the carbon budget of tropical mountain forests (S Ecuador): The role of the belowground compartment. Global Change Biology, 17(6), pp.2211–2226.
Moser, G., Hertel, D. & Leuschner, C., 2007. Altitudinal change in LAI and stand leaf biomass in tropical montane forests: A transect study in ecuador and a pan-tropical meta-analysis. Ecosystems, 10(6), pp.924–935.
Moser Gerald, Christoph Leuschner, Marina Röderstein, Sophie Graefe, N.S. and D.H., 2010. Biomass and productivity of fine and coarse roots in five tropical mountain forests stands along an altitudinal transect in southern Ecuador. Plant Ecology and Diversity, 3(2), pp.151–164. Available at: http://www.informaworld.com/index/713824049.pdf.
Motzer, T. et al., 2005. Stomatal conductance, transpiration and sap flow of tropical montane rain forest trees in the southern Ecuadorian Andes. Tree physiology, 25(10), pp.1283–1293.
Mulligan, M. and Burke, S.M., 2005. Global cloud forests and environmental change in a hydrological context http://www.ambiotek.com/cloudforests. Available at: http://www.ambiotek.com/cloudforests.
Myers, N. et al., 2000. Biodiversity hotspots for conservation priorities. Nature, 403(6772), pp.853–8. Available at: http://www.ncbi.nlm.nih.gov/pubmed/10706275.
Naeem, S. et al., 1996. Carbon Dioxide, Populations and Communities. In Carbon Dioxide, Populations and Communities. pp. 93–100.
Nair, U.S. et al., 2008. Biogeography of tropical montane cloud forests. Part II: Mapping of orographic cloud immersion. Journal of Applied Meteorology and Climatology, 47(8), pp.2183–2197.
Natelhoffer, K.J. & Fry, B., 1988. Controls on Natural Nitrogen-15 and Carbon-13 Abundances in Forest Soil Organic Matter. Soil Science Society of America Journal, 52(6), p.1633.
Needoba, J.A., Sigman, D.M. & Harrison, P.J., 2004. The mechanism of isotope fractionation during algal nitrate assimilation as illuminated by the 15N/14N of intracellular nitrate. Journal of Phycology, 40(3), pp.517–522. Available at: http://dx.doi.org/10.1111/j.1529-8817.2004.03172.x.
Nelson, B.W. et al., 1999. Allometric Regressions for Improved of Secondary Forest Biomass in the Central Amazon. Forest Ecology and Management, 117, pp.149–167.
Nenninger, A., 2006. Biomasseuntersuchungen an ausgewählten Baumarten des tropischen Bergregenwaldes Südecuadors.
Nierop, K.G.J. et al., 2007. Organic Matter in Volcanic Ash Soils under Forest and Páramo along an Ecuadorian Altitudinal Transect. Soil Science Society of America Journal, 71(4), p.1119.
Nogueira, E.M. et al., 2008. Estimates of forest biomass in the Brazilian Amazon: New allometric equations and adjustments to biomass from wood-volume inventories. Forest Ecology and Management, 256(11), pp.1853–1867.
Nottingham, A.T. et al., 2015. Nitrogen and phosphorus constrain labile and stable carbon turnover in lowland tropical forest soils. Soil Biology and Biochemistry, 80, pp.26–33.
Nottingham, A.T. et al., 2015. Soil microbial nutrient constraints along a tropical forest elevation gradient: A belowground test of a biogeochemical paradigm. Biogeosciences, 12(20), pp.6071–6083.
Oliveira, R.S. et al., 2014. The hydroclimatic and ecophysiological basis of cloud forest distributions under current and projected climates. Annals of Botany, 113(6), pp.909–920.
Pan, Y. et al., 2011. A large and persistent carbon sink in the world’s forests. Science (New York, N.Y.), 333(6045), pp.988–993.
Paoli, G.D., Curran, L.M. & Slik, J.W.F., 2008. Soil nutrients affect spatial patterns of aboveground biomass and emergent tree density in southwestern Borneo. Oecologia, 155(2), pp.287–299.
Parry, M.A.J. et al., 2008. Rubisco regulation: A role for inhibitors. In Journal of Experimental Botany. pp. 1569–1580.
Patrimonio ambiente, Ecuador, Vegetation maps of the government of Ecuador. Available at: http://patrimonio.ambiente.gob.ec/descargas.php [Accessed February 22, 2016].
Perez, 2010. Estimacion del carbono contenido en la biomasa forestal aerea de dos bosques andinos en los departamentos de Santander y Cundinamarca,
Phillips, O.L., 1998. Changes in the Carbon Balance of Tropical Forests: Evidence from Long-Term Plots. Science, 282(5388), pp.439–442.
Phillips, R.P., Brzostek, E. & Midgley, M.G., 2013. The mycorrhizal-associated nutrient economy: A new framework for predicting carbon-nutrient couplings in temperate forests. New Phytologist, 199(1), pp.41–51.
Pizarro, T., 1985. La composicion quimica del agua de alluvia y su influencia en el pH. Abstracts of the 12th Symposium on Natural Resources, Puerto Rico Department of Natural Resources, San Juan.
Quesada, C. a. et al., 2009. Regional and large-scale patterns in Amazon forest structure and function are mediated by variations in soil physical and chemical properties. Biogeosciences Discussions, 6, pp.3993–4057.
Quesada, C. a. et al., 2010. Variations in chemical and physical properties of Amazon forest soils in relation to their genesis. Biogeosciences, 7(5), pp.1515–1541.
Quesada, C.A. et al., 2012. Basin-wide variations in Amazon forest structure and function are mediated by both soils and climate. Biogeosciences, 9(6), pp.2203–2246.
Quesada, C.A. et al., 2011. Soils of Amazonia with particular reference to the RAINFOR sites. Biogeosciences, 8(6), pp.1415–1440.
R Core Team, 2014. R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing Vienna Austria, 0, pp.{ISBN} 3–900051–07–0. Available at: http://www.r-project.org/.
Raich, J.W. et al., 2006. Temperature influences carbon accumulation in moist tropical forests. Ecology, 87(1), pp.76–87.
Raich, J.W., Russell, A.E. & Vitousek, P.M., 1997. Primary productivity and ecosystem development along an elevational gradient on Mauna Loa, Hawai’i. Ecology, 78(3), pp.707–721.
Ramankutty, N. et al., 2007. Challenges to estimating carbon emissions from tropical deforestation. Global Change Biology, 13(1), pp.51–66.
Reed, S.C., Cleveland, C.C. & Townsend, A.R., 2008. Tree species control rates of free-living nitrogen fixation in a tropical rain forest. Ecology, 89(10), pp.2924–2934.
Reich, P.B. et al., 2006. Nitrogen limitation constrains sustainability of ecosystem response to CO2. Nature, 440(7086), pp.922–925.
Reich, P.B. & Hobbie, S.E., 2012. Decade-long soil nitrogen constraint on the CO2 fertilization of plant biomass. Nature Climate Change, 3(3), pp.278–282. Available at: http://dx.doi.org/10.1038/nclimate1694.
Reich, P.B., Hobbie, S.E. & Lee, T.D., 2014. Plant growth enhancement by elevated CO2 eliminated by joint water and nitrogen limitation. Nature Geosci, 7(12), pp.920–924. Available at: http://dx.doi.org/10.1038/ngeo2284\n10.1038/ngeo2284\nhttp://www.nature.com/ngeo/journal/v7/n12/abs/ngeo2284.html#supplementa….
Reich, P.B. & Walters, M.B., 1994. Photosynthesis-nitrogen relations in Amazonian tree species - II. Variation in nitrogen vis-a-vis specific leaf area influences mass- and area-based expressions. Oecologia, 97(1), pp.73–81.
Reinhardt, K. & Smith, W.K., 2008. Impacts of cloud immersion on microclimate, photosynthesis and water relations of Abies fraseri (Pursh.) Poiret in a temperate mountain cloud forest. Oecologia, 158(2), pp.229–238.
Ribeiro, G. et al., 2014. Allometry for juvenile trees in an Amazonian forest after wind disturbance. Jarq, 48(January 2013), pp.213–219.
Rich, P.M., 1987. Mechanical Structure of the Stem of Arborescent Palms. Botanical Gazette, 148(1), p.42.
Robertson, A.L. et al., 2010. Stem respiration in tropical forests along an elevation gradient in the Amazon and Andes. Global Change Biology, 16(12), pp.3193–3204. Available at: http://doi.wiley.com/10.1111/j.1365-2486.2010.02314.x [Accessed April 6, 2016].
Robinson, D., 2001. d15N as an integrator of the nitrogen cycle. Trends in ecology and evolution, 16(3), pp.153–162. Available at: http://www.sciencedirect.com/science/article/B6VJ1-429XTFM-M/1/59a55678….
Rollenbeck, R., Fabian, P. & Bendix, J., 2006. Precipitation dynamics and chemical properties in tropical mountain forests of Ecuador. Advances in Geosciences, 6, pp.73–76.
Rull, V., 2009. Microrefugia. Journal of Biogeography, 36(3), pp.481–484.
Rutishauser, E. et al., 2010. Contrasting above-ground biomass balance in a Neotropical rain forest. Journal of Vegetation Science, 21(4), pp.672–682.
S. Alvarez-Clare and M. Brooks, M.C.M., 2013. A direct test of nitrogen and phosphorus limitation to net primary productivity in a lowland tropical wet forest. Ecology. Available at: C:\PDfs\2013_0780.pdf.
Saldarriaga, J.G. et al., 1988. Long-Term Chronosequence of Forest Succession in the Upper Rio Negro of Colombia and Venezuela. The Journal of Ecology, 76(4), pp.938–958. Available at: http://www.jstor.org/stable/2260625?origin=crossref.
Salinas, N. et al., 2011. The sensitivity of tropical leaf litter decomposition to temperature: Results from a large-scale leaf translocation experiment along an elevation gradient in Peruvian forests. New Phytologist, 189(4), pp.967–977.
Santiago, L.S. & Mulkey, S.S., 2005. Leaf productivity along a precipitation gradient in lowland Panama: Patterns from leaf to ecosystem. Trees - Structure and Function, 19(3), pp.349–356.
Scaranello, M.A.D.S. et al., 2012. Height-diameter relationships of tropical Atlantic moist forest trees in southeastern Brazil. Scientia Agricola, 69(1), pp.26–37.
Schimel, D.S. et al., 2001. Recent patterns and mechanisms of carbon exchange by terrestrial ecosystems. Nature, 414(6860), pp.169–172.
Schulze, 2000. The Carbon and Nitrogen Cycle of Forest Ecosystems. Ecological Studies,Vol. 142.
Seibt, U. et al., 2008. Carbon isotopes and water use efficiency: Sense and sensitivity. Oecologia, 155(3), pp.441–454.
Sidle, R.C. et al., 2006. Erosion processes in steep terrain - Truths, myths, and uncertainties related to forest management in Southeast Asia. Forest Ecology and Management, 224(1-2), pp.199–225.
Sierra, 1999. Propuesta Preliminar de un Sistema de Clasificación de Vegetación para el Ecuador Continental. PhD Proposal.
Sierra, C.A. et al., 2007. Total carbon stocks in a tropical forest landscape of the Porce region, Colombia. Forest Ecology and Management, 243(2-3), pp.299–309.
Silver, 1994. Is nutrient availability related to plant nutrient use in humid tropical forests ? Oecologia, 98, pp.336–343.
Silver, W.L., 1998. The potential effects of elevated CO2 and climate change on tropical forest soils and biogeochemical cycling. Climatic change, 39(2-3), pp.337–361.
Sistla, S.A. & Schimel, J.P., 2012. Stoichiometric flexibility as a regulator of carbon and nutrient cycling in terrestrial ecosystems under change. New Phytologist, 196(1), pp.68–78.
Slik, J.W.F. et al., 2010. Environmental correlates of tree biomass, basal area, wood specific gravity and stem density gradients in Borneo’s tropical forests. Global Ecology and Biogeography, 19(1), pp.50–60.
Smith, A.P., Mar??n-Spiotta, E. & Balser, T., 2015. Successional and seasonal variations in soil and litter microbial community structure and function during tropical postagricultural forest regeneration: A multiyear study. Global Change Biology, 21(9), pp.3532–3547.
Soethe, N., Lehmann, J. & Engels, C., 2008. Nutrient availability at different altitudes in a tropical montane forest in Ecuador. Journal of Tropical Ecology, 24(04), pp.397–406. Available at: http://www.journals.cambridge.org/abstract_S026646740800504X.
Sollins, P. et al., 2009. Sequential density fractionation across soils of contrasting mineralogy: Evidence for both microbial- and mineral-controlled soil organic matter stabilization. Biogeochemistry, 96(1), pp.209–231.
Soria, R., 2014. Academic year 2013-2014 Aboveground carbon stock estimation of young reforested areas in Northern Ecuador.
Spracklen, D. V. & Righelato, R., 2014. Tropical montane forests are a larger than expected global carbon store. Biogeosciences, 11(10), pp.2741–2754.
Stadtmuller, T. & Agudelo, N., 1990. Amount and variability of cloud moisture input in a tropical cloud forest. Hydrology in mountainous regions I, (193), pp.25–32.
Steffen, W. et al., 1998. The terrestrial carbon cycle: Implications for the Kyoto Protocol. Science, 280(5368, 29 May), pp.1393–1394 ST – The terrestrial carbon cycle: Impl. Available at: http://links.jstor.org/sici?sici=0036-8075(19980529)3:280:5368<1393:TTC…; LB - Ste36\nhttp://links.jstor.org/sici?sici=0036-8075(19980529)3:280:5368<1393:TTC….
Stegen, J.C. et al., 2009. Above-ground forest biomass is not consistently related to wood density in tropical forests. Global Ecology and Biogeography, 18(5), pp.617–625.
Stegen, J.C. et al., 2011. Variation in above-ground forest biomass across broad climatic gradients. Global Ecology and Biogeography, 20(5), pp.744–754.
Stephenson, S.L., Schnittler, M. & Lado, C., 2004. Ecological characterization of a tropical myxomycete assemblage--Maquipucuna Cloud Forest Reserve, Ecuador. Mycologia, 96(3), pp.488–97. Available at: http://www.ncbi.nlm.nih.gov/pubmed/21148872.
Sterner, R.W. & Elser, J.J., 2002. Ecological stoichiometry: the biology of elements from molecules to the biosphere, Available at: http://books.google.com/books?hl=en&lr=&id=53NTDvppdYUC&oi=….
Strubbe, M., 2013. Variation of wood density and vessel traits along an altitude gradient in a tropical montane cloud forest in Ecuador.
Tanner, E., 1985. Jamaican montane forests: nutrient capital and cost of growth. The Journal of Ecology, 73(2), pp.553–568. Available at: http://www.jstor.org/stable/2260493.
Tanner, E.V.J., 1980. Four Montane Rain Forests of Jamaica : A Quantitative Characterization of the Floristics , the Soils and the Foliar Mineral Levels , and a Discussion of the Interrelations. Journal of Ecology, 68(3), pp.883–918.
Tanner, E.V.J. et al., 1990. Nitrogen and phosphorus fertilization of Jamaican montane forest trees*. Journal of Tropical Ecology, 6(02), p.231.
Tanner, E.V.J., Vltousek, P.M. & Cuevas, E., 1998. Experimental investigation of nutrient limitation of forest growth on wet tropical mountains. Ecology, 79(1), pp.10–22.
Tian, G.L. et al., 2007. Assessment of soil and plant carbon levels in two ecosystems (woody bamboo and pasture) in montane Ecuador. Soil Science, 172(6), pp.459–468. Available at: <Go to ISI>://000247353000004.
Toledo, M. et al., 2011. Climate is a stronger driver of tree and forest growth rates than soil and disturbance. Journal of Ecology, 99(1), pp.254–264.
Townsend, A.R. et al., 2007. Controls over foliar N:P ratios in tropical rain forests. Ecology, 88(1), pp.107–118.
Unger, M., Homeier, J. & Leuschner, C., 2012. Effects of soil chemistry on tropical forest biomass and productivity at different elevations in the equatorial Andes. Oecologia, 170(1), pp.263–274.
UN-REDD, 2013. Inventory of volume and biomass tree allometric equations for South Asia. , p.76.
Vincent, A.G., Turner, B.L. & Tanner, E.V.J., 2010. Soil organic phosphorus dynamics following perturbation of litter cycling in a tropical moist forest. European Journal of Soil Science, 61(1), pp.48–57.
Vitousek, P.M., 1984. LITTERFALL, NUTRIENT CYCLING, AND NUTRIENT LIMITATION IN TROPICAL FORESTS. , 65(1), pp.285–298.
Vitousek, P.M., 1984. Litterfall, nutrient cycling, and nutrient limitation in tropical forests. Ecology, 65(1), pp.285–298.
Vitousek, P.M. et al., 2010. Terrestrial phosphorus limitation: Mechanisms, implications, and nitrogen-phosphorus interactions. Ecological Applications, 20(1), pp.5–15.
Vitousek, P.M. et al., 1992. The Mauna Loa environmental matrix: foliar and soil nutrients. Oecologia, 89(3), pp.372–382.
Vitousek, P.M. & Sanford, R.L., 1986. Nutrient Cycling in Moist. , 17(1986), pp.137–167.
Vitousek, P.M., Turner, D.R. & Kitayama, K., 1995. Foliar nutrients during long-term soil development in Hawaiian montane rain forest. Ecology, 76(3), pp.712–720.
Walker, T.W. & Syers, J.K., 1976. The fate of phosphorus during pedogenesis. Geoderma, 15(1), pp.1–19.
Webster, G.L., 2007. Inventario de las plantas vasculares de un bosque montano nublado; Flora de la reserve Maquipucuna, Ecuador. Ediciones Abya Yala, Fundacion Maquipucuna, Corporacion SIMBIOE y Conservation International Ecuador. Quito, Ecuador.,
van de Weg, M.J. et al., 2014. Gross Primary Productivity of a High Elevation Tropical Montane Cloud Forest. Ecosystems, 17(5), pp.751–764.
van de Weg, M.J. et al., 2012. Photosynthetic parameters, dark respiration and leaf traits in the canopy of a Peruvian tropical montane cloud forest. Oecologia, 168(1), pp.23–34.
Whittaker, R.H., 1975. Communities and ecosystems,
Wilcke, W. et al., 2005. Coarse woody debris in a montane forest in Ecuador: Mass, C and nutrient stock, and turnover. Forest Ecology and Management, 205(1-3), pp.139–147.
Wilcke, W. et al., 2002. Nutrient storage and turnover in organic layers under tropical montane rain forest in Ecuador. European Journal of Soil Science, 53(1), pp.15–27.
Wolf, K. et al., 2011. Nitrogen availability links forest productivity, soil nitrous oxide and nitric oxide fluxes of a tropical montane forest in southern Ecuador. Global Biogeochemical Cycles, 25(4).
Worldclim, Worldclim database. Available at: http://www.worldclim.org/ [Accessed January 1, 2015].
Wright, S.J. et al., 2011. Potassium, phosphorus, or nitrogen limit root allocation, tree growth, or litter production in a lowland tropical forest. Ecology, 92(8), pp.1616–1625.
Wullaert, H. et al., 2010. Response of the N and P cycles of an old-growth montane forest in Ecuador to experimental low-level N and P amendments. Forest Ecology and Management, 260(9), pp.1434–1445. Available at: http://dx.doi.org/10.1016/j.foreco.2010.07.021.
Wuthrich, D., 2006. Google Earth Pro. Geospatial Solutions, 16, pp.30–32.
Xu, X., Thornton, P.E. & Post, W.M., 2013. A global analysis of soil microbial biomass carbon, nitrogen and phosphorus in terrestrial ecosystems. Global Ecology and Biogeography, 22(6), pp.737–749.
Yang, Y., Luo, Y. & Finzi, A.C., 2011. Carbon and nitrogen dynamics during forest stand development: a global synthesis. The New phytologist, 190(4), pp.977–989.
Yuan, Z.Y. & Chen, H.Y.H., 2009. Global trends in senesced-leaf nitrogen and phosphorus. Global Ecology and Biogeography, 18(5), pp.532–542.
Zach, A. et al., 2010. Patterns of wood carbon dioxide efflux across a 2,000-m elevation transect in an Andean moist forest. Oecologia, 162(1), pp.127–37. Available at: http://www.ncbi.nlm.nih.gov/pubmed/19707793 [Accessed April 6, 2016].
Zhang, Y. et al., 2009. Global pattern of NPP to GPP ratio derived from MODIS data: Effects of ecosystem type, geographical location and climate. Global Ecology and Biogeography, 18(3), pp.280–290.
Zimmermann, M. et al., 2009. Climate dependence of heterotrophic soil respiration from a soil-translocation experiment along a 3000 m tropical forest altitudinal gradient. European Journal of Soil Science, 60(6), pp.895–906.