Browsing by Author "Munoz-Gomez, Nayadeth"

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    Control of invasive conifers in temperate Andean forests promotes native vegetation restoration, but requires continuous management
    (2024) Fuentes-Ramirez, Andres; Vargas-Gaete, Rodrigo; Toy-Opazo, Octavio; Munoz-Gomez, Nayadeth; Salas-Eljatib, Christian; Pauchard, Anibal
    Non -native conifers have been planted widely because of their growth potential and wood quality. However, many of them have become invasive in the introduced ranges. In Chile, the initial introduction of non -native conifers helped the recovery of degraded land, but today some pine species present a high invasion risk when they are not properly managed, leading to detrimental impacts on natural ecosystems and biodiversity. Such is the case of Douglas fir ( Pseudotsuga menziesii ), a species listed as invasive in south -central Chile, as well as in many other countries, when it establishes beyond the original plantation range. The main goal of this research was to characterize the invasion pattern of P. menziesii within a recently-declared protected area nearby the Conguill & iacute;o National Park in the Andes Cordillera. We aimed at determining the key factors that promote the invasion of P. menziesii outside the original plantations. We established five 1,000 m 2 sampling transects (i.e., 100 x10 m), considering two invasion conditions: (i) within the native forest and (ii) far into open scrub areas, both adjacent to P. menziesii plantations. We measured forest structure, soil nutrients, the floristic composition and pine regeneration before and after controlling the invasion within each study conditions. We found that P. menziesii density and soil nutrient availability in the soil decreased with the distance from the plantation. In addition, an increase in native species cover was found after removing pines, but also noted the ability of P. menziesii to readily re-invade the native forest after removal. These results indicate the need for continuous control of P. menziesii , especially inside the native forest at the early stages of invasion. We discuss the need for better plantation management to prevent its spread into natural areas and protect native forests from non -native conifers invasion.
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    Spatio-Temporal Variation in Soil Nutrients and Plant Recovery across a Fire-Severity Gradient in Old-Growth Araucaria-Nothofagus Forests of South-Central Chile
    (2022) Fuentes-Ramirez, Andres; Almonacid-Munoz, Leonardo; Munoz-Gomez, Nayadeth; Moloney, Kirk A.
    Forest fires can alter essential ecosystem processes, including soil nutrient cycling, potentially cascading into permanent vegetation changes. This is key to elucidate in ecosystems where fires are infrequent. We assessed the effects of fire severity on the spatio-temporal response of soil nutrients and plant diversity in old-growth forests of south-central Chile, 1, 2, and 3 years after a fire that occurred in 2015. Within ancient, old-growth Araucaria araucana (Mol.) K. Koch and Nothofagus pumilio (Poepp. and Endl.) Krasser forests, ranging from areas burned with fire of high severity to unburned forests, we evaluated nitrogen (N), phosphorus (P), potassium (K), and soil organic matter (SOM) content using spatial interpolation to predict their spatial distribution and assessed their availability over time. We also assessed plant species richness and abundance following the fire. The availability of N noticeably increased during the first year after fire but rapidly decreased in the following years, especially in areas of high fire severity. P, K, and SOM were less affected by the fire, remaining more constant over time. In the short term, plant species richness and diversity significantly decreased in severely burned areas, but over time, they became more similar to those of the unburned forests. The time since a fire and its severity determine a heterogeneous distribution of soil nutrients, with N shifting to a significantly lower availability after fire, which was more notable in areas of high fire severity. Here, vegetation exhibited a decrease in plant diversity and the establishment of exotic species, likely producing cascading effects at the community level.