La ecología del olmo en Rumanía

The resistance of indigenous elm species to Dutch Elm Disease (DED) has been studied since 1991 with emphasis on natural forests. The situation varies with altitude, local conditions, species and with stand origin. The variability in morphological characteristics is important and some varieties are described. The taxonomy of elms in Romania, as in the whole of Europe, seems to be confusing (Ulmus ambigua was described in 1952 by Beldie in Flora of Romania). Natural hybrids between field elm and mountain elm were observed both in natural and artificial stands, especially in border zones for the altitudinal distribution of the species. Seedlings from the natural provenances and open pollinated seedlings from hybrids produced in the Dutch breeding programme were artificially inoculated with Ophiostoma ulmi- Buism.. Most of the seedlings died, but results show an important number of surviving individuals from natural provenances. In some natural and artificial stands, it was observed that beside transmission of the disease by insects (Scolytus spp.), it was spread through root sprouts especially in field elms, from the dead «mother tree» within a few years, as well as by root grafts to proximal healthy trees («biogroups»). Because of the genetic incompatibility of individuals in some cases, the grafting cannot succeed and neither can infection. In the natural forest where the ecosystem is in equilibrium and functions normally, DED is present but its damages are not so important. The study of elms in natural forests provides valuable information for the problems caused by DED.La resistencia a la grafiosis de las especies nativas de olmo ha sido estudiada desde 1991, haciendo especial énfasis en los bosques naturales. La situación varía con la altitud, las condiciones locales, las especies y el origen de la población. La variabilidad morfológica es grande, habiéndose descrito algunas variedades. La taxonomía de los olmos de Rumanía, como en el conjunto de Europa, es confusa (Ulmus ambigua fue descrito en 1952 por Beldie en Flora of Romania). Se ha observado la existencia de híbridos naturales entre el olmo campestre y el olmo de montaña, tanto en rodales naturales como en artificiales, sobre todo en la franja altitudinal de contacto entre ambas especies. Se ha inoculado artificialmente con Ophiostoma ulmi Buism. Una serie de brinzales de origen natural y de polinización abierta de híbridos procedentes del programa holandés de mejora genética. Aunque la mayor parte de los brinzales murió, los resultados muestran que hubo un número importante de ejemplares supervivientes de origen natural. En algunos rodales, tanto naturales como artificiales, se observó que, además de la trasmisión de la enfermedad por insectos (Scolytus spp.), hubo también, especialmente en olmo campestre, transmisión a través de rebrote de raíz, a los pocos años de la muerte del «árbol madre», así como por injerto de raíz con árboles próximos sanos («biogrupos»). Debido a la presencia en algunos casos de incompatibilidad genética de los individuos, el injerto no tiene éxito ni causa infección. En bosques naturales con el ecosiostema en equilibrio y que funcionan de una forma normal, la grafiosis está presente pero sus daños son poco importantes. El estudio de los olmos en bosques naturales proporciona información valiosa sobre los problemas causados por la grafiosis

RESTORATION OF JUPA PARK - LANDSCAPE AND WOOD SPECIES ANALYSIS USING GIS TECHNOLOGY

Jupa village belongs to the municipality of Caransebes. In 1795, the Capra Mansion was built in Jupa village, an imposing building around which Jupa Park was created. Both the mansion and the surrounding park have undergone dramatic changes in the last century. A general landscape analysis was performed based on the GIS and GNSS technologies. An inventory of the wood vegetation was also made and its ornamental value and vitality were assessed. The remnant 11 taxa were identified as follows: 10 tree species (5 native and 5 exotic broadleave trees) and 1 fruit tree. The present-day park landscape is the result of the long-term interaction of the park species with anthropic activities in a rural context. In order to restore a functional green space for the local community of Jupa village, a plan of rearrangement was conceived in compliance with the landscape architecture principles.

Selection of elms tolerant to Dutch elm Disease in south-west Romania

Ophoiostoma novo- ulmi continues to be one of the most dangerous invasive fungi, destroying many autochthonous elm forests and cultures throughout the world. Searching for natural genotypes tolerant to Dutch Elm Disease (DED) is one of the main objectives of silviculturists all over the northern hemisphere in order to save the susceptible elms and to restore their ecosystem biodiversity. In this regard, the first trial was established between 1991 and 1994, in south-west Romania (Padurea Verde, Timis, oara), using three elm species (Ulmus minor, U. glabra, and U. laevis) with 38 provenances. A local strain of Ophiostoma novo-ulmi was used to artificially inoculate all elm variants and the DED evolution was observed. Furthermore, in 2018–2021 the trial was inventoried to understand the local genotype reaction to DED in the local environmental conditions after almost 30 years. The outcomes of the present study proved the continuous presence of the infections in the comparative culture and its proximity, but the identified pathogen had a new hybrid form (found for the first time in Romania) between O. novo-ulmi ssp. Americana x O. novo-ulmi ssp. novo-ulmi. Wych elm (U. glabra) was extremely sensitive to DED: only 12 trees (out of 69 found in 2018) survived in 2021, and only one tree could be selected according to the adopted health criteria (resistance and vigour). The field elm (U. minor) was sensitive to the pathogen, but there were still individuals that showed good health status and growth. In contrast, the European white elm (U. laevis) proved constant tolerance to DED: only 15% had been found dead or presented severe symptoms of dieback. Overall, the results of this study report the diverse reactions of the Romanian regional elm genotypes to DED over the last three decades, providing promising perspectives for improving the presence of elms in the forest ecosystems of the Carpathian basin

FOREST BIODIVERSITY PRESERVATION IN ROMANIA

The biodiversity conservation strategy should include forest protected areas as important objectives. Important legislative and administrative measures should be taken in order to integrate the forestry better in the sustainable development of the natural capital of Romania. A list of the most valuable virgin and natural forests is included. The definitions given to forest indicators must be revived and adapted to the actual situation