Puna Grassland Research Articles

Cloud frequency climatology at the Andes/Amazon transition: 1. Seasonal and diurnal cycles

Tropical montane regions present a complex local climate but one that may be very sensitive to local and global change. Therefore, it is important to assess their current climatological state, and to understand how the large‐scale circulation may affect local‐scale cloud patterns. We examine the cloud climatology of a tropical Andean montane region in the context of tropical South American climate in terms of seasonal/diurnal cycles using a corrected ISCCP (International Satellite Cloud Climatology Project) DX cloud product (1983–2008), MODIS (Moderate Resolution Imaging Spectroradiometer) MOD35 visible cloud flags (2000–2008) and ground‐based cloud observations. Cloud climatologies were compared for three elevation zones: highlands (puna grassland), eastern slope (the montane forest) and lowlands. We found that in the dry season (JJA) the study area is part of a localized region of higher cloud frequency relative to other parts the eastern slope, and also relative to the adjacent highlands and lowlands. The highlands exhibited the greatest amplitude mean annual cycle of cloud frequency, with a minimum in June for all times of day. There were contrasts between the three zones with regard to the month in which the minimum cloud frequency occurs between different times of day. Higher lowland and eastern slope cloud frequencies compared with those on the puna in the early hours in the wet season suggest low‐level convergence at lower elevations. Comparisons between satellite products show that ISCCP and MODIS produce very similar annual cycles although the absolute cloud frequencies are higher in ISCCP data.

Cloud frequency climatology at the Andes/Amazon transition: 2. Trends and variability

The climate and ecology of tropical montane systems is intimately connected with the complex spatial dynamics of cloud occurrence, but there have been few studies of the patterns and trends of cloud occurrence in tropical montane regions. We examine trends and variability in the cloud climatology of the Andes/Amazon transition in SW Amazonia using satellite data and ground‐based observations. Results were compared for three zones within the study area: highlands (puna grassland), eastern slope (Tropical Montane Cloud Forest or TMCF) and lowlands. Time series of cloud frequency from ISCCP (International Satellite Cloud Climatology Project) were correlated with sea surface temperature (SST) anomalies from the HadISST data set for 5 regions including the tropical North Atlantic and the tropical Pacific. Detrended lowland cloud frequencies were significantly correlated with detrended tropical North Atlantic SSTs in the late dry season (August/September), whereas the eastern slope and the highlands were not significantly correlated with tropical North Atlantic SSTs. Pacific SST correlations were highest for eastern slope and highlands from March to May. Indian Ocean SST anomalies were significantly correlated with dry season cloud frequency for the lowlands and highlands. There are significant decreasing trends in cloud frequency on the lowlands in January, March and September and in March on the eastern slope. Trends in sunshine duration, 850 hPa zonal winds over the central Amazon, increases in diurnal temperature range, and comparisons with MODIS (Moderate Resolution Imaging Spectroradiometer) and observational data support the existence of these trends, and a link with the increasing trend in tropical North Atlantic SSTs. We suggest that continued increases in tropical North Atlantic SSTs will further reduce cloud frequency in the lowlands adjacent to the TMCF in the late dry season at least. In addition, a future increase in the occurrence of El Niño events would lead to decreased cloud frequency on the eastern slope and highlands.

Grasshoppers of the Andes: new Melanoplinae and Gomphocerinae taxa (Insecta, Orthoptera, Acrididae) from Huascarán National Park and Callejón de Huaylas, Ancash, Peru

The grasshopper fauna from Huascarán National Park and the valleys of “Callejón de Conchucos” and “Callejón de Huaylas”, Perú, has been sampled during two surveys of the area in 2004 and 2008. In this paper, two new genera (Tiyantiyana n. gen. and Huaylasacris n. gen.) and six new species collected during the surveys are described: Tiyantiyana sunipenis n. gen, n. sp., Huaylasacris maxicerci n. gen, n. sp., Maeacris chilikuti n. sp., M. saytu n. sp., M. ayasqa n. sp. of the subfamily Melanoplinae and Orphulella chumpi n. sp. of the subfamily Gomphocerinae. Previous records on the highland grasshoppers of the Peruvian Andes were almost nonexistent. The new acridids described here were collected at the high-altitude puna grassland, between 3182 and 4660 m a.s.l. Puna is one of the most heavily modified natural regions of Peru. Since grasshoppers are a useful group for bioindication, it is important to acquire knowledge on their diversity in such environmental conditions.This paper includes many embedded links to images of type specimens, maps based on geo-referenced specimen data, and keys to species, all available at Orthoptera Species File Online (http//orthoptera.speciesfile.org).

Bird community composition across an Andean tree‐line ecotone

AbstractFew studies have found strong evidence to suggest that ecotones promote species richness and diversity. In this study we examine the responses of a high‐Andean bird community to changes in vegetation and topographical characteristics across an Andean tree‐line ecotone and adjacent cloud forest and puna grassland vegetation in southern Peru. Over a 6‐month period, birds and vegetation were surveyed using a 100 m fixed‐width Distance Sampling point count method. Vegetation analyses revealed that the tree‐line ecotone represented a distinctive high‐Andean vegetation community that was easily differentiated from the adjacent cloud forest and puna grassland based on changes in tree‐size characteristics and vegetation cover. Bird community composition was strongly seasonal and influenced by a pool of bird species from a wider elevational gradient. There were also clear differences in bird community measures between tree‐line vegetation, cloud forest and puna grassland with species turnover (β‐diversity) most pronounced at the tree‐line. Canonical Correspondence Analysis revealed that the majority of the 81 bird species were associated with tree‐line vegetation. Categorizing patterns of relative abundance of the 42 most common species revealed that the tree‐line ecotone was composed primarily of cloud forest specialists and habitat generalists, with very few species from the puna grassland. Only two species, Thlypopsis ruficeps and Anairetes parulus, both widespread Andean species more typical of montane woodland vegetation edges, were categorized as ecotone specialists. However, our findings were influenced by significant differences in species detectability between all three vegetation communities. Our study highlights the importance of examining ecotones at an appropriate spatial and temporal scale. Selecting a suitable distance between sampling points based on the detection probabilities of the target bird species is essential to obtain an unbiased picture of how ecotones influence avian richness and diversity.

Fire and drought as drivers of early Holocene tree line changes in the Peruvian Andes

AbstractThree pollen and charcoal records from three lakes lying at 3400 m elevation in southern Peru provided a record of landscape change spanning the last ca.18 000 cal. a BP. The tree line lay close to the site between ca. 16 000 and 12 000 cal. a BP, with Polylepis woodlands growing near the lakes. Progressively drying conditions led to increased fire after 12 000 cal. a BP, coinciding with a decline in Polylepis cover and Andean forest relicts as puna grasslands expanded. A strong decrease in the rate of sediment deposition between ca. 12 000 and ca. 4400 cal. a BP was interpreted to indicate the presence of sedimentary hiatuses. With the return of wet conditions after 4400 cal. a BP, forests did not reassemble around the lakes. Instead, fire‐maintained grasslands dominated the landscape. Humans probably induced the intensified fire activity during the late Holocene and thereby deflected local successions. The modern fragmented landscape, with Polylepsis woodlands existing in fire‐resistant pockets above the general limit of the Andean tree line, resulted from the intensification of human land use practices during the last 4400 cal. a BP. Copyright © 2011 John Wiley & Sons, Ltd.

Ecosystem Carbon Storage Across the Grassland–Forest Transition in the High Andes of Manu National Park, Peru

Improved management of carbon storage by terrestrial biomes has significant value for mitigating climate change. The carbon value of such management has the potential to provide additional income to rural communities and provide biodiversity and climate adaptation co-benefits. Here, we quantify the carbon stores in a 49,300-ha landscape centered on the cloud forest–grassland transition of the high Andes in Manu National Park, Peru. Aboveground carbon densities were measured across the landscape by field sampling of 70 sites above and below the treeline. The forest near the treeline contained 63.4 ± 5.2 Mg C ha−1 aboveground, with an additional 13.9 ± 2.8 Mg C ha−1 estimated to be stored in the coarse roots, using a root to shoot ratio of 0.26. Puna grasslands near the treeline were found to store 7.5 ± 0.7 Mg C ha−1 in aboveground biomass. Comparing our result to soil data gathered by Zimmermann and others (Ecosystems 13:62–74, 2010), we found the ratio of belowground:aboveground carbon decreased from 15.8 on the puna to 8.6 in the transition zone and 2.1 in the forest. No significant relationships were found between carbon densities and slope, altitude or fire disturbance history, though grazing (for puna) was found to reduce aboveground carbon densities significantly. We scaled our study sites to the study region with remote sensing observations from Landsat. The carbon sequestration potential of improved grazing management and assisted upslope treeline migration was also estimated. Afforestation of puna at the treeline could generate revenues of US $1,374 per ha over the project lifetime via commercialization of the carbon credits from gains in aboveground carbon stocks. Uncertainties in the fate of the large soil carbon stocks under an afforestation scenario exist.

No Differences in Soil Carbon Stocks Across the Tree Line in the Peruvian Andes

Reliable soil organic carbon (SOC) stock measurements of all major ecosystems are essential for predicting the influence of global warming on global soil carbon pools, but hardly any detailed soil survey data are available for tropical montane cloud forests (TMCF) and adjacent high elevation grasslands above (puna). TMCF are among the most threatened of ecosystems under current predicted global warming scenarios. We conducted an intensive soil sampling campaign extending 40 km along the tree line in the Peruvian Andes between 2994 and 3860 m asl to quantify SOC stocks of TMCF, puna grassland, and shrubland sites in the transition zone between the two habitats. SOC stocks from the soil surface down to the bedrock averaged (±standard error SE) 11.8 (±1.5, N = 24) kg C/m2 in TMCF, 14.7 (±1.4, N = 9) kg C/m2 in the shrublands and 11.9 (±0.8, N = 35) kg C/m2 in the grasslands and were not significantly different (P > 0.05 for all comparisons). However, soil profile analysis revealed distinct differences, with TMCF profiles showing a uniform SOC distribution with depth, shrublands a linear decrease, and puna sites an exponential decrease in SOC densities with soil depth. Organic soil layer thickness reached a maximum (~70 cm) at the upper limit of the TMCF and declined with increasing altitude toward puna sites. Within TMCF, no significant increase in SOC stocks with increasing altitude was observed, probably because of the large variations among SOC stocks at different sites, which in turn were correlated with spatial variation in soil depth.

A New Species of Minute Noblella (Anura: Strabomantidae) from Southern Peru: The Smallest Frog of the Andes

We describe a new species of Noblella from the upper Cosñipata Valley in southern Peru (Cusco Region). Specimens were found in the leaf litter of a cloud forest between 3025 and 3190 m elevation. The most distinctive character of the new species is its diminutive size (maximum SVL female 12.4 mm, male 11.1 mm). With an average snout–vent length of 11.4 mm (n = 7) in adult specimens, the new species is the smallest Andean frog, and one of the smallest anurans in the world. The new frog is rare (between 30 and 75 frogs/ ha) and found only in montane scrub and forest habitats near the ecotone with the high-Andean puna grasslands. Although the amphibian fungal infection (Batrachochytrium dendrobatidis) has been recorded in southern Peru, no infections were detected in the new species.

Two sympatric new species of Phrynopus (Anura: Strabomantidae) from Yanachaga Chemillen National Park (central Peruvian Andes)

Two sympatric new species of Phrynopus (Anura: Strabomantidae) are described from elfin forests and puna grasslands (3363–3589 m) of the eastern slopes of the Andes of Departamento Pasco in central Peru. Phrynopus miroslawae sp. nov. is a medium-sized species characterized by lacking vomerine teeth and tympanic membrane, and by having dorsolateral folds, areolate ventral skin, dorsum gray with black spots, venter cream with small scattered black blotches, and iris bronze. Phrynopus nicoleae sp. nov. is a small species characterized by lacking tympanic membrane and by having vomerine teeth, an X-shaped middorsal fold, ventral skin areolate, dorsum tan with black stripes and bluish tubercles, and iris bronze with black reticulations.

Cercomacra manu, a New Species of Antbird from Southwestern Amazonia

Cercomacra manu, a New Species of Antbird from Southwestern Amazonia

Impacts of the 1982-1983 El Nino on Population Dynamics of Andean Condors in Peru

We studied how the environmental perturbations associated with the 1982-1983 El Niiio phenomenon affected the population dynamics of Andean condors (Vultur gryphus) in three areas of Peru. For at least four years prior to the 1982-1983 El Niiio, nearly all adult condors in a coastal population and an Andean foothill population refrained from breeding; whereas condors in a high-elevation population appeared to be breeding once every other year. The severe environmental disruptions of the 1982-1983 El Niiio caused the food supply for the coastal population of condors to decrease, while the food supply for the foothill population increased 17 fold. The food supply for the high-elevation population was little affected by El Niiio because climatic changes in the area were inconsequential. In response to the increase in food, almost all condors in the foothill population bred in the months following El Niiio. No condors in the coastal population bred after El Niiio, and breeding of condors in the high-elevation population was presumably unaffected. If they can reproduce only during the unpredictable El Niiio years, coastal and foothill condor populations may barely be able to maintain their numbers without ingress from more regularly breeding populations. The rate of breeding in these desert-dwelling condors seems to be the lowest recorded among birds. THE PHENOMENON OF EL NiNo is associated with the periodic occurrence and persistence of unusual oceanographic and climatic conditions along the coast of Peru and Ecuador (Cane 1983, Philander 1983, Rasmusson & Wallace 1983). Although most reports of the ecological consequences of El Ninio have focussed on its detrimental effects on animal movements, reproductive cycles, and survival (e.g., Murphy 1936, Barber & Chavey 1983, Karr 1984, Schreiber & Schreiber 1984), certain species should benefit. The food supply for carrion feeders, for example, should improve during an El Niiio event as stress resulting from environmental changes increases mortality rates in species on which they feed. We studied three populations of Andean condors (V. gryphus) in Peru before and after the 1982-1983 El Nifio and here report how the environmental disruptions associated with that El Ninio affected the population dynamics of this large carrion feeder. We found evidence that individuals in coastaland foothill-dwelling populations of condors breed very infrequently, if at all, in the drought years between El Nifio events; they seem to breed only in response to the flush of carrion resulting from environmental changes in El Ninio years. We discuss the implications of this irregular breeding pattern on the dynamics of these condor populations, and we contrast them with populations of condors high in the Andes where the environmental consequences of El Ninio are less pronounced. STUDY SITES We studied condors from May 1980 to August 1982 and from March 1984 to August 1984 in three areas of Peru: the Cerro Illescas on the Sechura Peninsula, the Olmos and Naupe regions in the western Andean foothills, and Pampa Galeras in the high Andes. The Cerro Illescas is a unique geological formation on Peru's northern coast. Located on the tip of the Sechura Peninsula (6?S, 80?W), this isolated mountain range is bordered on three sides by the Pacific Ocean and separated from the Andes Mountains to the east by over 150 km of sparsely vegetated desert. The mountains cover an area approximately 40 x 20 km and reach a maximum elevation of 480 m. From this central high point, dry steep-walled canyons radiate to the periphery of the hills and provide roosting and nesting ledges for condors. Our second study area was 150 km east of the Cerro Illescas in the western foothills of the Andes near the towns of Olmos (6.00?S, 79.46?W) and Naupe (5.350S, 79.46?W), which are 75 km apart. In these foothills that rise to about 1000 m, steep brushy slopes and precipitous escarpments isolate the roosting and nesting sites of condors from the activities of people living on the desert grasslands below. Our third study site was Pampa Galeras (14.400S, 74.23?W), a high-elevation puna grassland at an altitude of 41 00 m. This 5 12,000-ha, grassy plateau is occasionally transected by deep canyons that provide roosting and nesting ledges for condors.

A Visit to the Manu

To reach the Manu National Park means a day's journey by road over the Andes from Cusco, climbing up to the high puna grassland where one enters the park at the Tres Cruces guard post, 3300m above sea level. The last part of the road down to Shintuya at 300m has four unbridged river crossings that are impassable in the wet season from November to March. At Shintuya, if no park boat is available, the onward journey to Pakitsa, the administrative headquarters where there is accommodation, can only be made by hiring the Dominican Mission boat at $100 a day plus 30 gallons of gasoline (if you can get it) as well as enough for the return journey from Pakitsa to Cashu Cocha.