Estado del conocimiento y principales amenazas de los humedales boscosos de agua dulce de Chile

Abstract

RESUMENLos humed ales boscosos de agua dulce son áreas naturalmente inundadas o saturadas, que sustentan vegetación boscosa hidrófi la, están presentes en todo el mundo, y en Chile son conocidos como "pitrantos, hualves o hualhues". El presente estudio entrega el estado del conocimiento de estos humedales en Chile, mediante una descripción de sus características biológicas, fi sicoquímicas e hidrodinámicas, identifi cando las principales amenazas para su conservación y las principales necesidades de investigación. Estos ambientes pueden presentar inundación permanente o temporal, dependiendo de un conjunto de procesos microclimáticos, biológicos y edafológicos. Su vegetación, del tipo hidrófi la boscosa, es dominada por especies de la familia Myrtaceae. Tanto el comportamiento hídrico como la estructura vegetacional destacan dentro de los aspectos que determinan directamente las características fi sicoquímicas del agua y los patrones de distribución de las comunidades biológicas. Los humedales boscosos de Chile han sido ampliamente estudiados desde un punto de vista vegetacional y fl orístico, pero carecen de estudios limnológicos, hidrológicos o faunísticos básicos, de lo cual deriva un total desconocimiento en relación a su funcionamiento a nivel ecosistémico y los efectos que pueden tener las actividades humanas en sus cuencas (e.g., agrícola, ganadera, forestal) sobre sus componentes hídricos y biológicos. A pesar de ser ecosistemas de gran relevancia cultural y ecológica, se identifi can importantes falencias en cuanto a su estado de conservación, al no encontrarse protegidos por las actuales herramientas de conservación existentes en el país. Por lo tanto, emergen como ecosistemas únicos, de relevancia mundial, prácticamente desconocidos en Chile y de gran interés para el desarrollo de numerosas líneas de investigación, aunque su alta susceptibilidad ante perturbaciones de origen antrópico amenaza su permanencia en el tiempo.Palabras clave: agua dulce, Chile, cuencas, humedal boscoso, vegetac ión hidrófi la. ABSTRACTForested freshwater wetlands are naturally fl ooded or saturated areas with hydrophilic forest vegetation which is worldwide distributed and is known as "pitrantos, hualves o hualhues" in Chile. This paper gives to know the state of art of these wetlands in Chile, through a description of its biological, physical-chemical and hydro-dynamic characteristics, identifying the main threats to its conservation and the main research needs. These environments can be permanently or temporarily fl ooded, depending on microclimatic, biological and edaphical processes. Its vegetation is dominated by species of the family Myrtaceae. Both hydric behavior and vegetation structure are major aspects that directly determine the water physical-chemical characteristics and the distribution patterns of biological communities. Chile's forested wetlands have been studied broadly from a vegetation and fl oristic point of view, but basic studies on limnology, hydrology or fauna are lacking, which results on a total lac...

Ecophysiological responses to drought followed by re-watering of two native Chilean swamp forest plants: Myrceugenia exsucca (DC.) O. Berg and Luma chequen (Molina) A. Gray

“…Myrceugenia exsucca and Luma chequen are two evergreen species from the Myrtaceae family with fulfill important ecological functions (Correa-Araneda et al 2011, Solervicens & Elgueta 1994, Villagrán & Hinojoza 1997. Considering the destruction of their natural habitat and the possibility of their conservation under lower moisture soils conditions is important to accurate the drought tolerance and the capability of recovery after a drought episode.…”

“…These isolated, discontinuous forests fulfill important ecological functions related to watercourse protection, biological diversity conservation, and erosion and flood control (Correa-Araneda et al 2011, Solervicens & Elgueta 1994. Myrceugenia exsucca (DC.)…”

Leaf litter decomposition from native and non-native species in a freshwater forested wetland of Chile

“…These features make forested wetlands particularly vulnerable against the excessive input of organic matter as a result of the diverse productive activities carried out in the area. In addition, the loss of forest material as a result of its extraction for human consumption (Correa-Araneda et al 2011) can facilitate the input of light, generating changes in the thermal regime and in the related variables (Döll & Zhang 2010). The synergistic effect of these modifi cations might lead to a greater bacterial colonization (Molinero et al 1996), accelerating biological processes (Cortes 1992, Belovsky & Slade 2000 and in turn, causing a greater consumption of oxygen.…”

“…That is why any change in the type of vegetation that is incorporated into the water component of the forested wetlands would impact signifi cantly on the functioning of the system, affecting the capacity of processing this material (Graça & Canhoto 2006). However, the mechanisms are not entirely clear, since wetlands have been very poorly studied (Correa-Araneda et al 2011). Because of the abovementioned backgrounds, the present study is aimed to evaluate the degradation process of the leaf litter carried out by the communities of BF and BMI on the foliar component of native and non-native plants from the forested wetlands.…”

“…Arboreal vegetation of these ecosystems is fundamental for their Original Article functioning, because it causes a low penetration of light, limiting the primary activity of phytoplankton (Benfi eld 1996) and it implies that their main source of organic matter is the material coming from the woody component (e.g. leaves, twigs, fl owers and fruits) (Correa-Araneda et al 2011). This material has been mainly supplied by hydrophilic native species from the Myrtaceae family, such as Blepharocalyx cruckshanksii (Hook.…”