Iván A. Díaz

Old-Growth Temperate Rainforests of South America: Conservation, Plant-Animal Interactions, and Baseline Biogeochemical Processes

A structural and compositional definition of old-growth forest is presented, which places emphasis on the lack of recurrent human impact, the presence of a shade-tolerant canopy with emergent pioneers, and a patch area that minimises edge effects. Using this definition, we provide an overview of the current conservation status, relevance of plant–animal interactions, and unique features of nutrient fluxes in old-growth forests of southern South America. Chile hosts the largest area and latitudinal extent of old-growth temperate forest remaining in the southern hemisphere, reaching 56° S in the Cape Horn Archipelago. Despite recent public and private efforts to protect remaining old-growth forests and their endemic biodiversity, they continue to decline steeply as a result of new routes of access to commercial stands, lack of protection of coastal areas, anthropogenic fire, and expansion of monoculture-based forestry toward higher latitudes and altitudes. Pollinators (insects and birds) and vertebrate frugivores (birds and an arboreal marsupial) are important mutualists of many Chilean rain forest trees, vines and epiphytes. There is evidence to suggest that some native pollinators and animal seed vectors may be highly susceptible to changes in forest structure due to loss of old-growth forest cover. Forest fragmentation and loss of keystone, animal-pollinated emergent trees due to logging and fires, have radically changed pollinator assemblages in rural landscapes, leading to reproductive dependence on European honey bees and other exotic species. Regarding other ecosystem functions, nutrient cycles in unpolluted old-growth forests of southern Chile are characterised by strong inorganic nitrogen (N) retention and large organic N leakage to forest streams. Non-symbiotic N fixation in litter and soil tends to increase in older stands. Knowledge of these “unpolluted nutrient cycles”, particularly N and P, is still meager despite its relevance to understanding the consequences of increased global disruption of element cycles by humans. Development of baseline measurements and experiments in southern Chilean old-growth temperate forests can enhance our understanding of unpolluted ecosystem functioning.

Estación Biológica Senda Darwin: Investigación ecológica de largo plazo en la interfase ciencia-sociedad

This article discusses Senda Darwin Biological Station and the work of the scientists who study the anthropological role in ecological processes there.

Vertebrados terrestres de la Reserva Nacional Río Clarillo, Chile central: representatividad y conservación

Analizamos la representatividad, distribucion y perspectivas de conservacion de los vertebrados terrestres de la Reserva Nacional Rio Clarillo, Chile central. Mediante recorridos periodicos realizados entre 1987 y 1996, determinamos la riqueza y distribucion altitudinal de los vertebrados terrestres en esta Reserva. Registramos 127 especies (22 mamiferos, 85 aves, 15 reptiles y cinco anfibios), que representan el 69 % del total de especies que por su distribucion geografica y tipo de habitat podrian habitar este lugar. De estas, 32 especies (25 %) estan catalogadas con problemas de conservacion. La riqueza de vertebrados decrece con la altitud, desde 101 especies a los 870 m hasta ocho especies a los 3.050 m. La riqueza de vertebrados se concentro bajo los 1.600 m, albergando 109 especies, 55 de las cuales no se registraron a mayor altitud. En cambio, sobre los 1.600 m se registraron 57 especies. Paradojicamente solo el 31 % de la superficie de la Reserva esta bajo los 1.600 m. Nuestros resultados sugieren que la superficie de la Reserva no es suficiente para albergar poblaciones viables de la mayoria de los vertebrados registrados. Alrededor de la Reserva existen propiedades privadas con grandes extensiones de bosques esclerofilos bajo los 1.600 m, los cuales podrian actuar como fuentes y la Reserva como sumidero de vertebrados. Por lo tanto, sugerimos desarrollar estrategias de conservacion en estas areas y realizar monitoreos para determinar si las poblaciones de vertebrados mas sensibles estan aumentando o disminuyendo, tanto dentro como fuera de la Reserva

Composition patterns and network structure of epiphyte–host interactions in Chilean and New Zealand temperate forests

ABSTRACT Ecological networks are becoming increasingly used as a framework to study epiphyte–host interactions. However, efforts to quantify the properties of epiphyte–host networks have produced inconsistent results. Epiphyte–host interactions in New Zealand and Chilean temperate forests were quantified to test for non-random patterns in nestedness, negative co-occurrences, number of links, and network specialisation. Results showed that three out of five New Zealand networks were significantly more nested than null model expectations, compared with just one out of four Chilean networks. Epiphytes co-occurred more often than null model expectations in one New Zealand network and one in Chile. In all cases, the number of links maintained by each epiphyte and host species was consistent with null model expectations. Lastly, two New Zealand networks and one in southern Chile were significantly less specialised than null model expectations, with all remaining networks returning low specialisation scores. As such, aside from the tendency for greater nestedness in New Zealand networks, most epiphyte species were distributed on their host trees at random. We attribute the result of nestedness in New Zealand to the abundance of large nest epiphytes (Astelia spp. in particular), which may facilitate the sequential colonisation of epiphyte species on developing host trees. The lack of negative co-occurrences suggests that negative species interactions are not an important determinant of species assemblage structure. Low network specialisation scores suggest that epiphytes are selecting for specific host traits, rather than specific host species for colonisation.

An inexpensive portable platform for wildlife observation in the forest canopy

Resumen en: Since the 1980s, many canopy access methods have been developed, ranging from light, small and low-cost techniques to large, heavy and expensive ones. Ne...

First record on an amphibian in the canopy of temperate rainforests of southern South America: Eupsophus calcaratus (Cycloramphidae)

We record for the first time arboreal habits in amphibians from the temperate rainforests of southern South America. In April 2006 we collected an individual of Eupsophus calcaratus at 16 m height, in a large Eucryphia cordifolia tree of old-growth forest of Chiloe Island, southern Chile. This species was considered until now as a terrestrial species, and the similarities between forest ground and epiphytic layer may allow this species inhabit the canopy. However, the level of association among these frogs and the forest canopy is unknown. The canopy of southern South America forests remains barely known, and as other forest canopies, may support high species diversity.

Frugivory of Persea lingue (Lauraceae) and its effect on seed germination in southern Chile

La dispersion de semillas por endozoocoria es uno de los principales mecanismos de interaccion mutualista entre plantas y animales en el bosque templado de Sudamerica. En este estudio indagamos acerca de los mecanismos de dispersion primaria y estadios de depredacion de semillas de Persea lingue (Ruiz et Pav.) Nees (Lauraceae), arbol endemico de estos bosques. El objetivo principal fue determinar la identidad de los vertebrados dispersores de semillas de P. lingue, distinguiendo dispersores legitimos, de consumidores de pulpa y predadores de semillas, y determinar su efecto en la germinacion. Se realizaron observaciones focales de la copa de adultos de P. lingue; ademas, se instalaron trampas Sherman cebadas con frutos de P. lingue en fragmentos de bosque en el valle central del centro-sur de Chile. Se colectaron muestras de fecas y semillas regurgitadas, se determino cuales especies de roedores consumieron la pulpa, las semillas o los frutos enteros en las trampas. Se examino si hubo remocion de frutos y semillas desde el suelo. Se realizo un ensayo de germinacion para determinar si la forma de la remocion de la pulpa afecta las tasas de germinacion. Registramos seis especies de aves consumiendo frutos, ninguna defeco semillas, Turdus falcklandii Quoy & Gaimard (Turdinae) y Xolmis pyrope (Kittlitz) (Tyrannidae) regurgitaron semillas intactas. Capturamos cinco especies de roedores en las trampas, cuatro dejaron semillas intactas. No encontramos efecto del tipo de manipulacion de las semillas en su germinacion. La remocion de la pulpa fue determinante para el exito de germinacion. Concluimos que T. falcklandii y X. pyrope son dispersores legitimos de semillas de P. lingue. Abrothrix olivaceus (Waterhouse) (Cricetidae) y probablemente Oligoryzomys longicaudatus (Bennett) (Cricetidae) son potenciales dispersores secundarios, dada su marcada preferencia por la pulpa sobre las semillas.

FLORA VASCULAR DEL PARQUE FUTANGUE, REGIÓN DE LOS RÍOS (CHILE)

RESUMEN Se presentan los resultados del primer estudio floristico del Parque Futangue, un Area Silvestre Protegida (ASP) de los Bosques Templados del Sur de Sudamerica (BTSS), ubicado en la Cordillera de los Andes (40o 25’ S; 72o 16’ O), proximo al complejo volcanico Puyehue-Cordon del Caulle, Region de Los Rios. Se identificaron 295 especies, pertenecientes a 91 familias y 165 generos. Este parque representa una muestra importante de los BTSS ( ca. 40-70%). La flora de Futangue se caracteriza por un 66% de las especies de origen nativo, 8% catalogadas con problemas de conservacion, con un 19% de especies endemicas de Chile. La riqueza de especies supero lo esperado con respecto a otras areas silvestres cercanas. La escasa proporcion de especies introducidas y la baja cobertura observada de estas indicarian que Futangue presenta una baja alteracion antropica. Este reporte contribuye a llenar un vacio de registros para la zona y da cuenta de la importancia de mantener actualizado los listados de flora para planes de manejo y conservacion en ASP.

Bosque Pehuén Park's Flora: A Contribution to the Knowledge of the Andean Montane Forests in the Araucanía Region, Chile

ABSTRACT: In Chile, most protected areas are located in the southern Andes, in mountainous landscapes at mid or high altitudes. Despite the increasing proportion of protected areas, few have detailed inventories of their biodiversity. This information is essential to define threats and develop long-term integrated conservation programs to face the effects of global change. Consequently, the objectives of this study were to (1) describe the richness, conservation status, and species composition of the vascular flora found in Bosque Pehuén Park; and (2) analyze the relationships among altitude, species richness, and growth forms. Bosque Pehuén is one of the largest privately protected areas located within the Araucarias Biosphere Reserve, in southern Chile (39°S). The park is dominated by secondary forests that grew after intensive exploitation in the 1970s, with some remnant old-growth forests. Fifteen regularly distributed plots, 150 m in radius, were sampled. At each plot, all vascular plant species were recorded; 101 species were found, of which 79% are endemic, 10% are introduced, and 13% are currently listed in IUCN conservation categories. The highest richness was concentrated within the plots associated with riparian zones. The total richness tended to decrease with altitude. Epiphytes and climbers were only recorded at lower altitudes, making them the growth forms most influenced by altitude. The background information reported here is essential for effective park management and conservation of the vascular flora species found within this Andean montane forest.

New record of Podilymbus podiceps (Linnaeus, 1758) (Podicipediformes, Podicipedidae) in the Patagonian region of southern Chile

We report a new record of Podilymbus podiceps (Linnaeus, 1758) in the southern Chilean Patagonia, 120 km south of previous records on the western side of the Andes, and more than 400 km south of their known distribution area on the eastern side of the Andes. This is the southernmost record of this species in Chile and one of the southernmost records worldwide, highlighting the vagrancy of this species in southern Patagonia.