Teresa Fonseca

Evaluation of fire recurrence effect on genetic diversity in maritime pine (Pinus pinaster Ait.) stands using Inter-Simple Sequence Repeat profiles

The management of maritime pine in fire-prone habitats is a challenging task and fine-scale population genetic analyses are necessary to check if different fire recurrences affect genetic variability. The objective of this study was to assess the effect of fire recurrence on maritime pine genetic diversity using inter-simple sequence repeat markers (ISSR). Three maritime pine (Pinus pinaster Ait.) populations from Northern Portugal were chosen to characterize the genetic variability among populations. In relation to fire recurrence, Seirós population was affected by fire both in 1990 and 2005 whereas Vila Seca-2 population was affected by fire just in 2005. The Vila Seca-1 population has been never affected by fire. Our results showed the highest Neis genetic diversity (He=0.320), Shannon information index (I=0.474) and polymorphic loci (PPL=87.79%) among samples from twice burned populations (Seirós site). Thus, fire regime plays an important role affecting genetic diversity in the short-term, although not generating maritime pine genetic erosion.

Structural and floristic behaviors in East Timor forest vegetation

Owing to the growing demand for the products supplied and to the slowness of their renewal, forests, the most important renewable resource of the East Timor lands, will lose the goods and services they provide unless this situation is overcome. The communities that live in these forests or in their vicinity will be the most affected by this problem. Understanding the structural organization of the East Timor forest flora is, therefore, critical for sustainable management of this natural resource. Thus, the main purpose of this preliminary study was to identify the differences in the floristic–structural behaviors of the woody vegetation. The study is based on data collected by the first National Forest Inventory (2008–2010), carried out in two environmentally different districts of East Timor: one drier region located to the north (Bobonaro district) and the other more humid, located in the south (Covalima district). A two-stage sampling method was employed to account for species in 923 sample stations: 480 in the Bobonaro district and 443 in the Covalima district. These data were correlated with environmental variables (altitude, distance to sea, distance to the north coast, distance to roads, and distance to urban areas) and discussed based on the floristic–structural randomness of the species frequencies. Randomness was adopted here as a parameter to quantify the distributional relationship among species with spatial heterogeneity. Results show a higher percentage of species with low frequencies and abundances for the south (lower human pressure), in contrast with the north (higher human pressure). Altitude also emerges as an environmental parameter, since this randomness floristic–structural combination decreases from lower to higher altitudes. This research provides an innovative approach to describing the structural–floristic organization of vegetation, and its correlation with environmental variables.

An Integer Programming Model for the Management of a Forest in the North of Portugal

This study aims to develop an approach for the management of a forest of maritime pine located in the north region of Portugal. The forest is classified into five public lands, the so‐called baldios, extending over 4432 ha. These baldios are co‐managed by the Official Forest Services and the local communities mainly for timber production purposes. The forest planning involves non‐spatial and spatial constraints. Spatial constraints dictate a maximum clearcut area and an exclusion time. An integer programming model is presented and the computational results are discussed.