Miguel Marchamalo-Sacristán

UBRISTES: UAV-Based Building Rehabilitation with Visible and Thermal Infrared Remote Sensing

Building inspection is a critical issue for designing rehabilitation projects, which are recently gaining importance for environmental and energy efficiency reasons. Image sensors on-board unmanned aerial vehicles are a powerful tool for building inspection, given the diversity and complexity of facades and materials, and mainly, their vertical disposition. The UBRISTES (UAV-based Building Rehabilitation with vISible and ThErmal infrared remote Sensing) system is proposed as an effective solution for facade inspection in urban areas, validating a method for the simultaneous acquisition of visible and thermal aerial imaging applied to the detection of the main types of facade anomalies/pathologies, and showcasing its possibilities using a first principles analysis. Two public buildings have been considered for evaluating the proposed system. UBRISTES is ready to use in building inspection and has been proved as a useful tool in the design of rehabilitation projects for inaccessible, complex building structures in the context of energy efficiency.

Soil fertility characterisation of teak (Tectona grandis L.f.) plantations in Central America

Teak (Tectona grandis L.f.) is an important species in the worldwide quality tropical hardwood sector, which has gained significance in Central America since the first large plantations were established in the 1980s. The present work is a descriptive study that aims to: (1) analyse and characterise the general soil patterns which may be influencing teak plantations in Central America; (2) assess differences between countries and sub-regions; (3) create a global framework to help contextualise the soil fertility analyses conducted at sub-regional or farm level, and (4) determine the main problems associated with soil fertility in the region. Soil fertility was measured at 684 sites in Costa Rica, Guatemala and Panama. Although teak is considered to be a species with high soil nutrient requirements, and high fertility is usually assumed in teak plantations, the results show that this species has been planted in a wide variety of soils, including many with serious fertility problems (e.g. Ultisols and perhaps Oxisols) or with added difficulties due to their physical properties (e.g. Vertisols). The present analysis reveals a general K deficiency in the Central American teak plantations, where P deficiency and acidity toxicity are also relatively common problems. These soil fertility problems probably stem from poor site selection by forest managers in the 80s and 90s. Hence, although soil fertility is carefully evaluated when most teak plantations are established today, managers have to deal with soil fertility deficiencies in many sites where teak was established some years ago.

N-P-K fertilisation of teak (Tectona grandis) plantations: a case study in Costa Rica

The global importance of short rotation, intensively managed planted forests has increased over recent years due to the growing need for timber and other goods. In this kind of system, nutrient management is a key issue and fertilisation plays a double role: a) improving productivity and b) compensating nutrient output in order to attain sustainability and maintain productivity for further rotations. The need to replace nutrients, taken up by the growing forest or removed during timber extraction, has long been recognised (Rennie 1955). However, Fölster & Khanna (1997) stated that conventional forest management has shown a general lack of concern with regard to this problem. Several authors have recommended the application of fertiliser to sustain productivity in short-cycle plantations (FSC 2004, Rennie 1955, Gonçalves et al. 1997, Worrel & Hampson 1997). This is especially important in tropical forests where nutrient dynamics and tree growth take place more rapidly than temperate zones. Teak (Tectona grandis) is an important species worldwide in the quality tropical N-P-K FERTILISATION OF TEAK (TECTONA GRANDIS) PLANTATIONS: A CASE STUDY IN COSTA RICA