A pivotal nutritional potential of understory vascular plants in Patagonian forests

Abstract

Native forests can support wild and domestic herbivores, but their nutritional potential of understory vascular plants is rarely explored. We analysed the composition of understory plant species and their biochemical components to reveal the nutritional potential of forest types (deciduous, evergreen, mixed) and their associated open-lands (e.g. grasslands in forestlands) in Northern Patagonia. We proposed an approach combining our data (e.g. plant composition, occurrence frequency) with bibliographic research (e.g. Scopus database) to develop our findings. Data were evaluated using descriptive statistical analyses and multivariate analyses. This study presents the nutritional values for the 20 pivotal species under examination. The results highlight the significant impact of taxonomic families on nutritional profiles, where the species that presented the most relevant occurrence frequency: the herbs T. officinale (60.4% of total occurrence frequency-TOF) and T. repens (47.9% TOF), the graminoid H. lanatus (58% TOF), and the fern B. penna marina (44.4% TOF). Multivariate analyses showed that the first two PCA axes explained 76.1% (p = 0.001) and 10.5% (p = 1.000) of forest type variation, with ñire forests and open-lands having the highest palatable plant coverage. Biochemical PCA axes explained 52.1% (p = 0.024) and 22.5% (p = 0.874) of the variation, distinguishing species by protein content and structural components. The deciduous forests exhibited the highest coverage of palatable plants, while target plants with low palatability and high coverage were predominantly found in evergreen forest types. The confirmed presence of pivotal species across forest types and open-lands underscores its nutritional potential, characterised by highly digestible dry matter, crude protein, highly digestible non-nitrogenous nutrients, and relative feed value. Considering their widespread distribution and nutritional factors, the native and non-native plants merit attention due to their pivotal nutritional potential.