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L.a. Bruijnzeel - One of the best experts on this subject based on the ideXlab platform.

  • Assessing Atlantic Cloud Forest extent and protection status in southeastern Brazil
    Journal for Nature Conservation, 2018
    Co-Authors: Patrícia Vieira Pompeu, Marco Aurélio Leite Fontes, Mark Mulligan, Inácio Thomaz Bueno, Marinez Ferreira De Siqueira, Fausto Weimar Acerbi Júnior, Luciana Hiromi Yoshino Kamino, Maarten J. Waterloo, L.a. Bruijnzeel
    Abstract:

    Abstract This study aims to map the spatial distribution of Atlantic Cloud Forest and assess its protection status in the Serra da Mantiqueira, southeastern Brazil, using a combination of predictive distribution modelling and remote sensing techniques. The potential distribution of Cloud Forests in the Serra da Mantiqueira was predicted using a combination of three algorithms for different environmental variables, including climatic, hydrometeorological, a topographic variable and a fog-related variable. After estimating the potential Cloud Forest distribution, remote sensing mapping techniques were used to approximate actual Cloud Forest area. Four land-use classes were distinguished: Cloud Forest, plantation Forest, a ‘high-altitude complex’, and ‘other covers’. Actual mapped Cloud Forest areas were compared with locations of existing protected areas to assess the status of regional Cloud Forest protection. Predicted Cloud Forest distribution was excellent, with conditions above 1500 m.a.s.l. generally the most suitable for Cloud Forest occurrence. Actual Cloud Forest occurrence mapped with remote sensing imagery was 52% of the predicted potential area with differences likely due to past Forest loss and the presence of non-Forest (‘high-altitude complex’) vegetation. Much of the mapped Cloud Forest area is under nominal protection, with most areas falling into the ‘Protected Area with Sustainable Use of Natural Resources’ category. The combined use of predictive distribution modelling and remotely sensed observations successfully mapped Cloud Forest extent in the study area. The results reinforce the need to assign high conservation priority to the Serra da Mantiqueira as a whole and to create a core area with full protection status.

  • rainfall fog and throughfall dynamics in a sub tropical ridge top Cloud Forest national park of garajonay la gomera canary islands spain
    Hydrological Processes, 2011
    Co-Authors: Glenda Garciasantos, L.a. Bruijnzeel
    Abstract:

    Mixed tree-heath/beech Forest is a type of subtropical montane Cloud Forest found on wind- and fog-exposed ridges in the Canary Islands. With a dry season of 5 months and an annual precipitation of 600–700 mm, the extra water inputs through fog interception assume particular importance in this environment. Measurements were made of rainfall, fog occurrence, wind speed and direction as well as of throughfall (TF) in a ridge top Cloud Forest located near the centre of the National Park of Garajonay on the island of La Gomera. Measured amounts of incident rainfall were corrected for wind-induced losses around the gauge and for topographic effects. Amounts of fog water as collected by a 0·25-m2 fog screen were corrected for changes in effective screen surface collection area depending on wind direction. No such corrections were taken into account in most if not all previous studies of rainfall and fog water inputs in the Canary Islands. TF fractions differed between events with rain-only (87% of wind-corrected rainfall), fog-only (∼6% of wind-corrected fog) and mixed precipitation (110%). It is concluded that the fog screen was more efficient at capturing fog water than the Forest canopy, whereas previous wetting of the canopy and bryophytes by rain may have caused the higher TF fraction found on days with rainfall and fog. Copyright © 2010 John Wiley & Sons, Ltd.

  • Tropical Montane Cloud Forests: Environmental controls on photosynthetic rates of lower montane Cloud Forest vegetation in south-western Colombia
    Tropical Montane Cloud Forests, 2011
    Co-Authors: M. G. Letts, Mark Mulligan, M. E. Rincón-romero, L.a. Bruijnzeel
    Abstract:

    A variety of microclimatic and edaphic factors have been shown to limit photosynthetic productivity in tropical montane Cloud Forest (TMCF) ecosystems. It is now understood that multiple controls may limit photosynthesis within individual TMCFs, and that the relative importance of each control varies between sites. This chapter describes the nutrient status, microclimate, leaf structural traits and photosynthetic gasexchange characteristics of lower montane Cloud Forest (LMCF) vegetation at the Centro de Estudios Ambientales Tambito site, a wet LMCF reserve located on the Pacific slopes of Colombia’s Western Cordillera. Neither periodic water shortage nor prolonged waterlogging was observed at Tambito. Total soil nitrogen and available phosphorus were above the range typically observed in lowland evergreen rain Forests (LERF), while exchangeable calcium levels were lower. In terms of soil nutrient status, total nitrogen and available phosphorus at Tambito were above the range typically observed in more productive LERF, while exchangeable calcium levels were lower. Leaf nutrient contents observed at Tambito were broadly similar to values observed in LERF. Photosynthetic photon flux density (PPFD) remained well below the light-saturation level for leaf-scale photosynthesis (A) throughout the day during the wet season and for 21 hours day � 1 during the dry season. Cloudiness may reduce the competitive advantage of high Amax in canopy leaves, thereby increasing the fitness of alternative traits conferred by low specific leaf area, including nutrient-use efficiency and leaf longevity. Therefore, it was concluded that persistent PPFD limitation of photosynthesis may help to explain the prevalence of sclerophylly in tropical montane Cloud Forests.

  • Characteristics of fog and fogwater fluxes in a Puerto Rican elfin Cloud Forest
    Agricultural and Forest Meteorology, 2006
    Co-Authors: Werner Eugster, Reto Burkard, Friso Holwerda, F N Scatena, L.a. Bruijnzeel
    Abstract:

    The Luquillo Mountains of northeastern Puerto Rico harbours important fractions of tropical montane Cloud Forests. Although it is well known that the frequent occurrence of dense fog is a common climatic characteristic of Cloud Forests around the world, it is poorly understood how fog processes shape and influence these ecosystems. Our study focuses on the physical characteristics of fog and quantifies the fogwater input to elfin Cloud Forest using direct eddy covariance net flux measurements during a 43-day period in 2002. We used an ultrasonic anemometer–thermometer in combination with a size-resolving Cloud droplet spectrometer capable of providing number counts in 40 droplet size classes at a rate of 12.5 times per second. Fog occurred during 85% of the time, and dense fog with a visibility

  • estimating fog deposition at a puerto rican elfin Cloud Forest site comparison of the water budget and eddy covariance methods
    Hydrological Processes, 2006
    Co-Authors: F Holwerda, Reto Burkard, Werner Eugster, F N Scatena, A G C A Meesters, L.a. Bruijnzeel
    Abstract:

    The deposition of fog to a wind-exposed 3 m tall Puerto Rican Cloud Forest at 1010 m elevation was studied using the water budget and eddy covariance methods. Fog deposition was calculated from the water budget as throughfall plus stemflow plus interception loss minus rainfall corrected for wind-induced loss and effect of slope. The eddy covariance method was used to calculate the turbulent liquid Cloud water flux from instantaneous turbulent deviations of the surface-normal wind component and Cloud liquid water content as measured at 4 m above the Forest canopy. Fog deposition rates according to the water budget under rain-free conditions (0! 11 " 0! 05 mm h # 1 ) and rainy conditions (0! 24 " 0! 13 mm h # 1 ) were about three to six times the eddy-covariance-based estimate (0! 04 " 0! 002 mm h # 1 ). Under rain-free conditions, water-budget-based fog deposition rates were positively correlated with horizontal fluxes of liquid Cloud water (as calculated from wind speed and liquid water content data). Under rainy conditions, the correlation became very poor, presumably because of errors in the corrected rainfall amounts and very high spatial variability in throughfall. It was demonstrated that the turbulent liquid Cloud water fluxes as measured at 4 m above the Forest could be only $ 40% of the fluxes at the canopy level itself due to condensation of moisture in air moving upslope. Other factors, which may have contributed to the discrepancy in results obtained with the two methods, were related to effects of footprint mismatch and methodological problems with rainfall measurements under the prevailing windy conditions. Best estimates of annual fog deposition amounted to $ 770 mm year # 1 for the summit Cloud Forest just below the ridge top (according to the water budget method) and $ 785 mm year # 1 for the Cloud Forest on the lower windward slope (using the eddy-covariance-based deposition rate corrected for estimated vertical flux divergence). Copyright ! 2006 John Wiley & Sons, Ltd.

Kevin J Anchukaitis - One of the best experts on this subject based on the ideXlab platform.

  • tropical Cloud Forest climate variability and the demise of the monteverde golden toad
    Proceedings of the National Academy of Sciences of the United States of America, 2010
    Co-Authors: Kevin J Anchukaitis, Michael N Evans
    Abstract:

    Widespread amphibian extinctions in the mountains of the American tropics have been blamed on the interaction of anthropogenic climate change and a lethal pathogen. However, limited meteorological records make it difficult to conclude whether current climate conditions at these sites are actually exceptional in the context of natural variability. We use stable oxygen isotope measurements from trees without annual rings to reconstruct a century of hydroclimatology in the Monteverde Cloud Forest of Costa Rica. High-resolution measurements reveal coherent isotope cycles that provide annual chronological control and paleoclimate information. Climate variability is dominated by interannual variance in dry season moisture associated with El Nino Southern Oscillation events. There is no evidence of a trend associated with global warming. Rather, the extinction of the Monteverde golden toad (Bufo periglenes) appears to have coincided with an exceptionally dry interval caused by the 1986–1987 El Nino event.

  • stable isotope chronology and climate signal calibration in neotropical montane Cloud Forest trees
    Journal of Geophysical Research, 2008
    Co-Authors: Kevin J Anchukaitis, Michael N Evans, Nathaniel T Wheelwright, Daniel P Schrag
    Abstract:

    without annual growth rings. High-resolution d 18 O measurements are used to identify regular cycles in wood of up to 9%, which are associated with seasonal changes in precipitation and moisture sources. The calculated annual growth rates derived from the isotope time series match those observed from long-term basal growth measurements. Interannual variability in the oxygen isotope ratio of lower Forest trees is primarily related to interannual changes in wet season precipitation. Forward modeling independently supports our detection of both annual chronology and a climate signal. The confirmation of annual chronology and sensitivity to interannual climate anomalies suggests that tropical Cloud Forest dendroclimatology can be used to investigate local and regional hydroclimatic variability and change.

Rafael S Oliveira - One of the best experts on this subject based on the ideXlab platform.

  • environmental controls in the water use patterns of a tropical Cloud Forest tree species drimys brasiliensis winteraceae
    Tree Physiology, 2015
    Co-Authors: Cleiton B Eller, Stephen S O Burgess, Rafael S Oliveira
    Abstract:

    Trees from tropical montane Cloud Forest (TMCF) display very dynamic patterns of water use. They are capable of downwards water transport towards the soil during leaf-wetting events, likely a consequence of foliar water uptake (FWU), as well as high rates of night-time transpiration (Enight) during drier nights. These two processes might represent important sources of water losses and gains to the plant, but little is known about the environmental factors controlling these water fluxes. We evaluated how contrasting atmospheric and soil water conditions control diurnal, nocturnal and seasonal dynamics of sap flow in Drimys brasiliensis (Miers), a common Neotropical Cloud Forest species. We monitored the seasonal variation of soil water content, micrometeorological conditions and sap flow of D. brasiliensis trees in the field during wet and dry seasons. We also conducted a greenhouse experiment exposing D. brasiliensis saplings under contrasting soil water conditions to deuterium-labelled fog water. We found that during the night D. brasiliensis possesses heightened stomatal sensitivity to soil drought and vapour pressure deficit, which reduces night-time water loss. Leaf-wetting events had a strong suppressive effect on tree transpiration ( E). Foliar water uptake increased in magnitude with drier soil and during longer leaf-wetting events. The difference between diurnal and nocturnal stomatal behaviour in D. brasiliensis could be attributed to an optimization of carbon gain when leaves are dry, as well as minimization of nocturnal water loss. The leaf-wetting events on the other hand seem important to D. brasiliensis water balance, especially during soil droughts, both by suppressing tree transpiration (E) and as a small additional water supply through FWU. Our results suggest that decreases in leaf-wetting events in TMCF might increase D. brasiliensis water loss and decrease its water gains, which could compromise its ecophysiological performance and survival during dry periods.

Hugh P. Possingham - One of the best experts on this subject based on the ideXlab platform.

  • extinction risk in Cloud Forest fragments under climate change and habitat loss
    Diversity and Distributions, 2013
    Co-Authors: Rocio Poncereyes, Richard A. Fuller, Emily Nicholson, Peter W J Baxter, Hugh P. Possingham
    Abstract:

    Aim To quantify the consequences of major threats to biodiversity, such as climate and land-use change, it is important to use explicit measures of species persistence, such as extinction risk. The extinction risk of metapopulations can be approximated through simple models, providing a regional snapshot of the extinction probability of a species. We evaluated the extinction risk of three species under different climate change scenarios in three different regions of the Mexican Cloud Forest, a highly fragmented habitat that is particularly vulnerable to climate change. Location Cloud Forests in Mexico. Methods Using Maxent, we estimated the potential distribution of Cloud Forest for three different time horizons (2030, 2050 and 2080) and their overlap with protected areas. Then, we calculated the extinction risk of three contrasting vertebrate species for two scenarios: (1) climate change only (all suitable areas of Cloud Forest through time) and (2) climate and land-use change (only suitable areas within a currently protected area), using an explicit patch-occupancy approximation model and calculating the joint probability of all populations becoming extinct when the number of remaining patches was less than five. Results Our results show that the extent of environmentally suitable areas for Cloud Forest in Mexico will sharply decline in the next 70years. We discovered that if all habitat outside protected areas is transformed, then only species with small area requirements are likely to persist. With habitat loss through climate change only, high dispersal rates are sufficient for persistence, but this requires protection of all remaining Cloud Forest areas. Main conclusions Even if high dispersal rates mitigate the extinction risk of species due to climate change, the synergistic impacts of changing climate and land use further threaten the persistence of species with higher area requirements. Our approach for assessing the impacts of threats on biodiversity is particularly useful when there is little time or data for detailed population viability analyses.

  • extinction risk in Cloud Forest fragments under climate change and habitat loss
    Science & Engineering Faculty, 2013
    Co-Authors: Rocio Poncereyes, Richard A. Fuller, Emily Nicholson, Peter W J Baxter, Hugh P. Possingham
    Abstract:

    Aim: To quantify the consequences of major threats to biodiversity, such as climate and land-use change, it is important to use explicit measures of species persistence, such as extinction risk. The extinction risk of metapopulations can be approximated through simple models, providing a regional snapshot of the extinction probability of a species. We evaluated the extinction risk of three species under different climate change scenarios in three different regions of the Mexican Cloud Forest, a highly fragmented habitat that is particularly vulnerable to climate change. Location: Cloud Forests in Mexico. Methods: Using Maxent, we estimated the potential distribution of Cloud Forest for three different time horizons (2030, 2050 and 2080) and their overlap with protected areas. Then, we calculated the extinction risk of three contrasting vertebrate species for two scenarios: (1) climate change only (all suitable areas of Cloud Forest through time) and (2) climate and land-use change (only suitable areas within a currently protected area), using an explicit patch-occupancy approximation model and calculating the joint probability of all populations becoming extinct when the number of remaining patches was less than five. Results: Our results show that the extent of environmentally suitable areas for Cloud Forest in Mexico will sharply decline in the next 70 years. We discovered that if all habitat outside protected areas is transformed, then only species with small area requirements are likely to persist. With habitat loss through climate change only, high dispersal rates are sufficient for persistence, but this requires protection of all remaining Cloud Forest areas. Main conclusions: Even if high dispersal rates mitigate the extinction risk of species due to climate change, the synergistic impacts of changing climate and land use further threaten the persistence of species with higher area requirements. Our approach for assessing the impacts of threats on biodiversity is particularly useful when there is little time or data for detailed population viability analyses. © 2013 John Wiley & Sons Ltd.

  • RESEARCH Extinction risk in Cloud Forest fragments under climate change and habitat loss
    2013
    Co-Authors: Rocío Ponce-reyes, Richard A. Fuller, Emily Nicholson, Peter W J Baxter, Hugh P. Possingham
    Abstract:

    Aim To quantify the consequences of major threats to biodiversity, such as climate and land-use change, it is important to use explicit measures of species persistence, such as extinction risk. The extinction risk of metapopulations can be approximated through simple models, providing a regional snapshot of the extinction probability of a species. We evaluated the extinction risk of three species under different climate change scenarios in three different regions of the Mexican Cloud Forest, a highly fragmented habitat that is particularly vulnerable to climate change. Location Cloud Forests in Mexico. Methods Using Maxent, we estimated the potential distribution of Cloud Forest for three different time horizons (2030, 2050 and 2080) and their overlap with protected areas. Then, we calculated the extinction risk of three contrasting vertebrate species for two scenarios: (1) climate change only (all suitable areas of Cloud Forest through time) and (2) climate and land-use change (only suitable areas within a currently protected area), using an explicit patch-occupancy approximation model and calculating the joint probability of all populations becoming extinct when the number of remaining patches was less than five. Results Our results show that the extent of environmentally suitable areas for Cloud Forest in Mexico will sharply decline in the next 70 years. We discovered that if all habitat outside protected areas is transformed, then only species with small area requirements are likely to persist. With habitat loss through climate change only, high dispersal rates are sufficient for persistence, but this requires protection of all remaining Cloud Forest areas. Main conclusions Even if high dispersal rates mitigate the extinction risk of species due to climate change, the synergistic impacts of changing climate and land use further threaten the persistence of species with higher area requirements. Our approach for assessing the impacts of threats on biodiversity is particularly useful when there is little time or data for detailed population viability analyses.

  • vulnerability of Cloud Forest reserves in mexico to climate change
    Nature Climate Change, 2012
    Co-Authors: Rocio Poncereyes, Jeremy Vanderwal, James E.m. Watson, Richard A. Fuller, Robert L. Pressey, Victorhugo Reynosorosales, Hugh P. Possingham
    Abstract:

    Tropical montane Cloud Forests are among the most vulnerable terrestrial ecosystems to climate change(1-3) owing to their restricted climatic requirements and their narrow and fragmented distribution(4). Although 12% of Mexican Cloud Forest is protected, it is not known whether reserves will ensure the persistence of the ecosystem and its endemic species under climate change. Here, we show that 68% of Mexico's Cloud Forest could vanish by 2080 because of climate change and more than 90% of Cloud Forest that is protected at present will not be climatically suitable for that ecosystem in 2080. Moreover, if we assume unprotected Forests are cleared, 99% of the entire ecosystem could be lost through a combination of climate change and habitat loss, resulting in the extinction of about 70% of endemic Cloud Forest vertebrate species. Immediate action is required to minimize this loss-expansion of the protected-area estate in areas of low climate vulnerability is an urgent priority. Our analysis indicates that one key area for immediate protection is the Sierra de Juarez in Oaxaca. This area supports many endemic species and is expected to retain relatively large fragments of Cloud Forest despite rapid climate change.

  • Vulnerability of Cloud Forest reserves in Mexico to climate change
    Nature Climate Change, 2012
    Co-Authors: Rocío Ponce-reyes, Víctor Hugo Reynoso-rosales, Jeremy Vanderwal, James E.m. Watson, Richard A. Fuller, Robert L. Pressey, Hugh P. Possingham
    Abstract:

    Tropical montane Cloud Forests are among the most vulnerable terrestrial ecosystems to climate change owing to their restricted climatic requirements and their narrow and fragmented distribution. Although 12% of Mexican Cloud Forest is protected, it is not known whether reserves will ensure the persistence of the ecosystem and its endemic species under climate change. Here, we show that 68% of Mexico's Cloud Forest could vanish by 2080 because of climate change and more than 90% of Cloud Forest that is protected at present will not be climatically suitable for that ecosystem in 2080. Moreover, if we assume unprotected Forests are cleared, 99% of the entire ecosystem could be lost through a combination of climate change and habitat loss, resulting in the extinction of about 70% of endemic Cloud Forest vertebrate species. Immediate action is required to minimize this loss-expansion of the protected-area estate in areas of low climate vulnerability is an urgent priority. Our analysis indicates that one key area for immediate protection is the Sierra de Jua rez in Oaxaca. This area supports many endemic species and is expected to retain relatively large fragments of Cloud Forest despite rapid climate change. © 2012 Macmillan Publishers Limited. All rights reserved.

Aline Horwath - One of the best experts on this subject based on the ideXlab platform.

  • bryophyte stable isotope composition diversity and biomass define tropical montane Cloud Forest extent
    Proceedings of The Royal Society B: Biological Sciences, 2019
    Co-Authors: Aline Horwath, Jessica Royles, Richard Tito, Jose A Gudino, Noris Salazar Allen, William Farfanrios, Joshua M Rapp, Miles R Silman
    Abstract:

    Liverworts and mosses are a major component of the epiphyte flora of tropical montane Forest ecosystems. Canopy access was used to analyse the distribution and vertical stratification of bryophyte epiphytes within tree crowns at nine Forest sites across a 3400 m elevational gradient in Peru, from the Amazonian basin to the high Andes. The stable isotope compositions of bryophyte organic material (13C/12C and 18O/16O) are associated with surface water diffusive limitations and, along with C/N content, provide a generic index for the extent of Cloud immersion. From lowland to Cloud Forest δ13C increased from −33‰ to −27‰, while δ18O increased from 16.3‰ to 18.0‰. Epiphytic bryophyte and associated canopy soil biomass in the Cloud immersion zone was estimated at up to 45 t dry mass ha−1, and overall water holding capacity was equivalent to a 20 mm precipitation event. The study emphasizes the importance of diverse bryophyte communities in sequestering carbon in threatened habitats, with stable isotope analys...