<p>Fire-prone ecosystems evolved and have been managed by humans with fire for<br>millennia. Ignoring these socioecological realities, zero-fire policies have been<br>implemented in fire-prone ecosystems across the world. These inappropriate policies are<br>mainly originated from a forest-centered perception that fire is an essentially negative<br>and anthropogenic disturbance. The attempts to exclude fires have generated deleterious<br>ecological impacts, high fire-fighting costs, damage to properties and human lives in<br>grasslands, savannas and Mediterranean-type ecosystems. These zero-fire policies also<br>generate conflicts between governments and local communities who use fire to manage<br>the landscape, food production and livestock raising. Excluding fires from fire-prone<br>ecosystems may lead to changes ecosystem functioning and biodiversity due to woody<br>encroachment and/or fuel load accumulation. In regions where soil conditions allow<br>grasslands can be invaded by trees, changing vegetation structure and their ability to<br>provide ecosystem services, especially water production. In most fire-prone ecosystems,<br>fuel load accumulates, and the long-time unburned areas become time bombs waiting<br>for the next ignition source to cause disastrous wildfires. Fire bans disrupt traditional<br>fire management practices and commonly lead to more irresponsible uses of fire, since<br>local communities continue to depend on fire for their productive areas but use fire in<br>furtive ways to avoid criminalization. In combination with large areas with high and<br>homogeneous fuel loads, this leads to large, hard to control and highly impacting<br>wildfires, especially during late-dry season, when fires tend cause more severe impacts.<br>After decades under these scenarios, zero-fire policies have been substituted by active<br>fire management policies in fire-prone ecosystems in many countries in Africa, Latin<br>America, in the US and Australia, among other countries. Fire management policies<br>should be adapted for each regional socioecological context and allow for the active use<br>of fires for landscape management, biodiversity conservation and/or productive<br>activities. The Brazilian savanna (Cerrado) is the most biodiverse and threaten savanna<br>in the world and has been managed under zero-fire policy for decades. It is a tropical<br>humid savanna (1,500mm mean annual precipitation) where large (&gt;10,000 hectares),<br>frequent (2-4 years fire interval) late-dry season wildfires are common, including in<br>Protect Areas (PA) dedicated to biodiversity conservation and traditional communities&#8217;<br>livelihoods. In 2014, a pilot Integrated Fire Management (IFM) program has been<br>implemented in three Cerrado PAs. The program considers local uses of fire,<br>implements prescribed burns and landscape management planning aiming to (i) change<br>the main season of burnings (from late- to early- and mid-dry season); (ii) protect fire-<br>sensitive vegetation, such as riparian forests, from fires; (iii) decrease firefighting costs;<br>(iv) reduce conflicts with local communities and (v) lower greenhouse gases emissions.<br>The IFM program has since been implemented in more than 30 federal PA, including<br>Indigenous Territories., where this approach has successfully achieved its main<br>objectives. The present challenge is to expand IFM actions to the state and especially<br>private -owned lands, which will allow for a significant change in wildfire patterns<br>across the whole 2 million km 2 of the Brazilian savanna.</p>
Assessing canopy fuel stratum characteristics in crown fire prone fuel types of western North America
