The response to drought of 20 open-pollinated families from four Pinus pinaster Ait. populations covering a latitudinal cline (France, Central and Southern Spain, and Morocco) was assessed. The seedlings were cultivated in a greenhouse under controlled temperature and vapor pressure deficit for 120 days, and subjected to two watering regimes for 60 days. Different biomass partitioning variables, pre-dawn water potential, and isotopic discrimination of 13C in needles (Δ) as surrogate of long-term water use efficiency were estimated for each seedling at the end of the experiment. In response to the imposed drought, there was no change in the root biomass partitioning, but the overall Δ values decreased in response to water stress. All the families of the population from Morocco showed the highest investment in roots, regardless of the watering regime imposed. Inter-family differences within populations were also significant for most parameters as confirmed by the heritability values estimated (higher under the well-watered treatment). The studied P. pinaster populations showed different strategies of response to drought. This may represent an important mechanism by local populations in facing future climatic change. The results could be of value in forest conservation and breeding programs of maritime pine in the future.
We compared the performance of mycorrhiza-inoculated and non-inoculated radiata pine (Pinus radiata D. Don) seedlings in two field studies. In the first study, aboveground growth of 2-year-old container-grown trees was compared after planting in two areas that differed in water availability. Mycorrhizal inoculation significantly improved aboveground growth in the 2 years after planting in both areas, especially at the drier site. In the second study, the influence of Rhizopogon roseolus (Corda ex Sturm) Th. Fries and Scleroderma citrinum Pers. on xylem water potential and hydraulic conductance at the soil–root interface of trees established at the same sites was assessed. Nursery inoculations with R. roseolus and S. citrinum improved tree growth during the first 2 years after field outplanting, particularly at the drier site.
Although citizenship’s literacy in biodiversity is a promising way of confronting its loss, the unawareness about this topic is generalised particularly regarding plants. The latter phenomenon, named Plant Blindness (PB), not only refers to the inability to notice and identify the surrounding plants, but also to the lack of knowledge about the basics of plant biology and to the subsequent ignorance of the value of plants. Hence, the aim of this research has been to assess whether secondary students experience PB and to analyse if this phenomenon can be interrelated with their conceptualisation and attitudes towards biodiversity. For this purpose, 63 secondary students took a mixed closed- and open-ended questionnaire on different aspects of biodiversity and plant biology. The results revealed that, despite conceptualisation of biodiversity and plant literacy increased during secondary education, most students presented PB ‘symptoms’. Moreover, some of the dimensions studied were interrelated, such as comprehension of biodiversity and different aspects of plant knowledge. Therefore, these results indicate that PB has multiple branches which are not only related to plant topics sensu stricto, but also include biodiversity; which can provide novel insights into the appropriate approach to the plant blindness issue from an educational perspective.
We have studied the development in nurseries of containerized Pinus radiata produced with different container systems in order to choose the most suitable system for producing well-balanced plants with an optimal root system. At the end of the production period, significant differences were found in morphological responses among the seedlings to the various container characteristics. Seedlings grown in containers that permitted lateral air puning presented less growth and lower biomass production. However, root deformations were more frequent and severe in plants produced in closed-wall containers. Field performance was likewise mainly affected by container type and plant growth rate, as faster grown plants showed more problems of stability than plants with a balanced root and stem development.