a - How can we manage forests to increase NWFP yields?

Time and dose of irrigation impact Tuber melanosporum proliferation in young black truffle orchards

Wild truffle producing mediterranean landscape

Tuber melanosporum, the fungus that produces the priced Black Truffle, is adapted to Mediterranean droughts.  Usually the production of truffles increases in years with higher precipitation. This hinted early farmers into watering the orchards to obtain better crops, but, what happens if we water too much?  One of the reasons we do not find truffles in forests with abundant rains could be that in wetter conditions other fungi can outcompete T. melanosporum and displace it from the roots of the trees causing the disappearance of the fungus and the end to truffle production...

Maritime pine silvicultural models - what do we know?

Resin tapped maritime pine stand

In Portugal, traditionally, the maritime pine is the species exploited to obtain resin. The silvicultural models used assume timber as the main product and resin as the secondary product, this being a periodic and annual source of income for the owner. The description of silvicultural models that make timber and resin exploitation compatible is essential and should be based on knowledge.

The influence of formation pruning in the cork tree growth rate: a case study.

Pruned cork oak trees

The formation pruning is an operation usually defined in forest management plans established for cork oak stands plantations. It aims at removing tree branches, usually the lower ones, therefore promoting the development of a long-straight stem, at least up to the expected future debarking height. This will later on facilitate cork harvesting operations.

It is unclear if the pruning intensity affects the tree growth. This factsheet shows the results of a case study where tree growth was compared between trees not pruned, and trees subject to two pruning intensities.

Potential chestnut map in Castile and Leon

Working the results of the model with farmers, El Bierzo (León)

The main objective is to know the potential distribution of chestnut (Castanea sativa) in Castile and Leon through the use of spatial modelling tools based on 13 different variables. The aim has been to determine where the bioclimatic and geographical conditions are most suitable for the species to prosper. These models allow to evaluate in a quantitative way the possibility that a chestnut population occupies a specific area.

Stone pine (Pinus pinea) grafting

Stone pine grafting

There are several requirements and experiences for a successfull graft, that are reviewed in the following from a practical point of view.

In coastal regions like the Portuguese Alentejo or Catalonian Empordà, grafting is usually performed directly in the field on young plantations, by specialised teams of skilled forest workers.  In-nursery grafting on container-raised rootstocks is an alternative, not discussed here, for harsher climate conditions where in situ grafting has a low success rate due to unpredictable spring weather (rain, wind, or late frost in some years,...

Accessing site productivity in cork oak stands in Portugal

18 years old cork oak stand in Coruche, Portugal.

In recent decades, new cork oak plantation areas have been established in Portugal, not only in the traditional areas of distribution of the species but also in the northern parts. Historical records show that the species was formerly present here, and climatic thresholds suggest a possible occurrence. Cork oak site productivity, assessed through site index, was modelled in relation to soil and climate variables. The models were developed to estimate and map the site index value along the cork oak potential distribution area in Portugal.

Resin production according to heath type

Maritime pine forest in the Landes

The objective of this project is to characterize the links between the production of maritime pine resin and the properties of the station. The program is particularly interested in the influence of soil (rather than climatic variations).

The experiment is conducted on the three types of stations that dominate in the Landes: dry heath, mesophilic heath and wet heath The results could make it possible to identify the most productive and therefore more interesting areas for the resin tapper.

Boletus edulis yields are influenced by the basal area of the forest stand

Pinar Grande

The purpose of the study was to develop empirical models for predicting the fresh weight yield of the target species Boletus edulis, one of the most appreciated fungal species worldwide. The objective of the models is to identify the influential factors that drive the sporocarp emergence.  The modeling process was applied to the “Pinar Grande” area (Soria province, Spain), where we analyzed fifteen years of mushroom data continuously recorded in eighteen permanent plots.    

Thinning of dense forest stands can increase the Lactarius group deliciosus yields

Pinus forests

In 2008, we installed 14 mushroom inventory plots of 100 m2 size in Pinus pinaster forests. The plots were selected to include a range of geographical features (altitude, slope, aspect) as well as variation in tree density and basal area in the conservation area of Poblet. A second set of plots were installed in 2009 paired to the first set of plots. The second set of plots was thinned removing 26 to 77% of the basal area. Mushroom yields were monitored on a weekly basis in the Autumn Season of the years 2008 to 2010 to analyze the effects of forest thinning on the yields of ...