Selective Shrub Management to Preserve Mediterranean Forests and Reduce the Risk of Fire: The Case of Mainland Portugal

Abstract

The recurrent rural fires that occur annually in Portugal have reached great proportions due to a lack of effective landscape management. Attempts to solve this problem led to the legal imposition to cut back the vegetation in the fuel management areas, which has had a negative effect on biodiversity. National legislation protects three native plant species (Quercus suber, Q. rotundifolia and Ilex aquifolium). European legislation, through the Habitats Directive, also identifies some plant species that require strict protection, although it leaves out several endemic and rare plants. In this work we aim to differentiate the types of shrub plant material and their pyrophilic behavior, since the physical and chemical characteristics of vegetation can enhance or inhibit the progression of fire. Thus, based on phytosociological science, specifically at the class level, the dynamics of potential climatophilous vegetation in Portugal are presented and the classes that should be prioritized for control are identified. Based on ecology, it was possible to identify morphological patterns of vegetation. In short, the genera targeted for control under the National Forest Fire Protection Plan belong to the furthest states from the mature potential of a forest, generally consisting of heliophile shrubs and typically growing in degraded soils. The shrub species to be valued belong to dynamic states closer to the mature potential, consisting mainly of broad-leaved shrubs and those growing in better-preserved soils.

A Historical Perspective of Landscape and Human Population Dynamics in Guimarães (Northern Portugal): Possible Implications of Rural Fire Risk in a Changing Environment

“…This work analyzed the evolution and regional distribution of the number of ignitions and burnt areas for each one of the districts of mainland Portugal, having confirmed the existence of a positive trend in the number of fires and in the areas burnt by fires since 1980, detecting a regional distribution of ignitions and burnt areas, highlighting some regions particularly vulnerable to the outbreak of fires and others particularly susceptible to the spread of fire. As previously mentioned, supported by the work of Nunes et al (2020) or Raposo et al (2020) [13,63], the main cause of fires in Portugal is the misuse of fire, mainly associated with negligence during the processes of burning agriculture and forestry remnants, and which was once again confirmed by the work of Nunes (2012), in which it is stated that the population density was the primary determining variable in the outbreak of fires, with the burnt areas being influenced by the effects of topography, changes in land use, and changes in the type of vegetation cover [38].…”

“…In this way, the growing pressure of urbanization on the forest space, together with the conversion also into new agriculture areas, led to the weakening of the resilience of the forests, also enhanced by the introduction of exotic species, which are replacing native species, less capable of react quickly to the effects of climate change. This replacement of species, in addition to the highly negative impact related to the loss of biodiversity, also contributes to these disordered forests to accumulate large amounts of fuel load, and with this, increasing the risk of occurrence of rural fires [13,63].…”

“…It often provides the only point of contact with the natural environment to which urban populations have access [10,11]. In addition to this access facilitated by the proximity, this rural agroforest interface also presents the only possibility for providing a set of ecosystem services, increasingly recognized and valued, that go far beyond the simple provision of an environment for leisure activities or for agricultural and forestry production [12,13]. The ecosystem services most easily identified are, without doubt, the production of oxygen, the protection of water resources, the fixation and protection of soils and biodiversity preservation [14][15][16].…”

“…Fire 2021, 4, x FOR PEER REVIEW 2 of 24 providing a set of ecosystem services, increasingly recognized and valued, that go far beyond the simple provision of an environment for leisure activities or for agricultural and forestry production [12,13].…”

Importance of Plants with Extremely Small Populations (PSESPs) in Endemic-Rich Areas, Elements Often Forgotten in Conservation Strategies

“…In Europe, Ophioglossum vulgatum usually grows in a variety of wet and mesic habitats, including wet and peaty meadows, marshes, stream edges, and hygrophilous woodlands from sea level up to 1800 m [ 56 , 57 ]; it is generally considered as a characteristic species of the wet and oligotrophic Molinion caeruleae alliance [ 57 ], which, according to the 92/43/EEC Directive, refers to the habitat of European interest “Molinia meadows on calcareous, peaty or clayey-silt-laden soils ( Molinion caeruleae) ” (code 6410). Mainly due to its wide distribution, O. vulgatum has been assessed as LC at European level [ 58 ], nevertheless, currently ferns and lycophytes have to face a new kind of risk related to ongoing climate change and human-related environmental disturbances such as eutrophication, pollution, habitat loss, alteration of hydrological regimes, and overexploitation [ 59 , 60 , 61 , 62 ]. Few data were available on the distribution of this small fern, and the conservation status at regional level (Italian and/or Sardinian) was not yet assessed.…”