ABSTRACT
Urban trees are important to maintain biodiversity and, therefore, need public acceptance. Few studies, however, have addressed the topic of social acceptability of old trees. The aim of this research was to examine city residents' perception of old trees, including hollow-bearing ones, mainly in the aspect of safety and aesthetics. A total of 448 Warsaw municipal forest' users expressed their opinions by completing an online questionnaire. Several methods were used to analyse the results of the study: the Chi-square test of independence, the Kruskal-Wallis H test, the Mann-Whitney U test and the Quartimax method of factor rotation analysis. The results revealed a correlation between the frequency of forest visits and the level of sensitivity toward old trees, which translates to less radical notion of danger and less radical decisions about cutting such trees down. Age of the respondents (56+) was a factor contributing to higher willingness to protect and care for old trees. The results also indicated that outdoor activity in the urban forest may increase ancient trees acceptance by developing emotional connection with them, and eventually contribute to their protection.
Subject(s)
Forests , Trees , Cities , BiodiversityABSTRACT
In the process of dating the oldest trees, which are often hollow, we developed a new method that combines tree-ring cross dating and wiggle matching radiocarbon techniques on wood samples extracted from the stem and from exposed roots. The method can be illustrated by the following steps: â¢crossdated tree-ring series from trunk cores reveal a multi-century tree age, and the hollow section is large enough to contain several more years (decades to centuries)â¢exposed roots can be cored for acquiring wood samples older than the stem cores and for construction of a floating root average tree-ring seriesâ¢if synchronization between stem and exposed roots is unclear, proceed to date the root wood samples by radiocarbon wiggle matching; match root and stem tree-ring series within the radiocarbon-dated period to more accurately date the tree. This new multistep dating method allowed for refining the age estimation of the oldest Pinus heldreichii tree in Pollino National Park by 166 years, to 789 CE. This tree, which we named Italus, was 1229 years old in 2017, making it the oldest, scientifically dated, living tree in Europe. Any study that relies on tree age determination for paleo-reconstructions, for biological and genetic research on what controls longevity, or for understanding structural dynamics and succession in old-growth forests, would potentially benefit from the multistep dating method we tested.
ABSTRACT
Studies on nesting ecology have proven to be extremely important for stingless bees conservation. This kind of study is scarce in urban landscapes. Our study aimed to analyze the abundance, density, diversity, spatial distribution and nesting habits of species belonging to the Meliponina subtribe in an urban area of the Uberlândia municipality, Minas Gerais state. We checked potential nesting sites by searching for nests from October 2009 until April 2010. We collected six worker bees from each detected nest to identify species, and estimated diversity and analyzed the spatial distribution pattern of the nests using the ShannonWiener and Nearest Neighbor index, respectively. We found fifty nests belonging to seven species, with Nannotrigona testaceicornis being the most abundant species (44%). The density of nests was 2.17 nests/ha, the ShannonWiener diversity index was H'=1.58 and the clumped distribution was the detected dispersal pattern. The height of the nests in relation to the ground varied from 0 to 12 m: Trigona spinipes had the highest nests and the highest variation for this parameter. Hollow trees were the preferred substrate occupied by the observed bees species (70%): Caesalpinia peltophoroides was the preferred plant species for nesting. Our results suggested that urban landscapes can sustain a high diversity of stingless bees, and maintaining trees species and urban forestry projects are important tools for the conservation of this group of animals. This type of study provides relevant information to the development of management and conservation plans for Meliponina species.
Estudos sobre ecologia de nidificação tem se mostrado extremamente necessários para a conservação de espécies de abelhas sem ferrão. Em ambientes urbanos, estudos desse tipo são escassos. O presente trabalho teve como objetivo analisar a abundância, densidade, diversidade, distribuição espacial e os hábitos de nidificação de espécies da subtribo Meliponina em uma área urbana do município de Uberlândia-MG. No período de outubro de 2009 a abril de 2010, os possíveis locais de nidificação foram vistoriados. Seis operárias de cada ninho foram coletadas para identificação das espécies e os índices de Shannon-Wiener e do vizinho mais próximo foram aplicados para estimativa da diversidade e análise do padrão de distribuição espacial dos ninhos, respectivamente. Foram encontrados 50 ninhos de abelhas sem ferrão pertencentes a sete espécies, sendo Nannotrigona testaceicornis a mais abundante (44%). A densidade de ninhos foi de 2,17 ninhos/ha, o índice de diversidade de Shannon-Wiener foi H'=1,58 e a distribuição espacial dos ninhos ocorreu de forma agregada. A altura da entrada dos ninhos em relação ao solo variou, de modo geral, de 0 a 12 m, sendo Trigona spinipes a espécie com os ninhos mais altos e com a maior variação. O tipo preferencial de substrato ocupado pelas espécies encontradas foram ocos de árvores (70%), sendo Caesalpinia peltophoroides a espécie vegetal mais utilizada. Os resultados obtidos sugerem que ambientes urbanos podem apresentar uma alta diversidade de abelhas sem ferrão e que a manutenção de espécies arbóreas e projetos de arborização são importantes para a conservação de espécies desse grupo de animais. Trabalhos nesse sentido fornecem informações relevantes para a elaboração de planos de manejo e conservação de espécies de Meliponina.
