Adapting the botanical landscape of Melbourne Gardens(Royal Botanic Gardens Victoria)in response to climate change

Botanic gardens around the world maintain collections of living plants for science, conservation, education, beauty and more. These collections change over time-in scope and content-but the predicted impacts of climate change will require a more strategic approach to the succession of plant species and their landscapes. Royal Botanic Gardens Victoria has recently published a 'Landscape Succession Strategy'for its Melbourne Gardens, a spectacular botanical landscape established in 1846. The strategy recognizes that with 1.6 million visitors each year, responsibility for a heritage-listed landscape and the need to care for a collection of 8500 plant species of conservation and scientific importance, planting and planning must take into account anticipated changes to rainfall and temperature. The trees we plant today must be suitable for the climate of the twenty-second century. Specifically, the Strategy sets out the steps needed over the next twenty years to transition the botanic garden to one resilient to the climate modelled for2090. The document includes a range of practical measures and achievable(and at times somewhat aspirational) targets. Climate analogues will be used to identify places in Australia and elsewhere with conditions today similar to those predicted for Melbourne in 2090, to help select new species for the collection. Modelling of the natural and cultivated distribution of species will be used to help select suitable growth forms to replace existing species of high value or interest. Improved understanding of temperature gradients within the botanic garden, water holding capacity of soils and plant water use behaviour is already resulting in better targeted planting and irrigation. The goal is to retain a similar diversity of species but transition the collection so that by 2036 at least 75% of the species are suitable for the climate in 2090. Over the next few years we hope to provide 100% of irrigation water from sustainable water sources, and infrastructure will be improved to adapt to predicted higher temperatures and more climatic extremes. At all times there will be a strong focus on assisting the broader community in their response to climate change.

Assessing forest fragmentation in north-western Himalaya:a case study from Ranikhet forest range,Uttarakhand,India

The northwestern Himalaya harbors high levels of biodiversity due to its unique topography, climatic conditions and heterogeneity. Forest fragmentation is one of the major threats causing a decline in biodiversity in the Himalayan region. We assesses forest fragmentation and changes in land use land cover（LULC） patterns using multi-temporal satellite data over a time span of four decades（1976–2013）. Fragmentation analysis using the Landscape Fragmentation Tool（LFT） reveals a decrease in core and edge areas by 14 and 2.3 %, respectively; while an increase in non-forest, patch area and perforation area by 2.1, 0.4, and 14 %, respectively. The LULC dynamics show that the areas under dense forest and scrub forest have decreased by 2.8 % and 1.9 %, respectively; and there is an increase in open forest, crop land and fallow land area by 2.6, 1.7 and 2.1 %, respectively. The quantification of landscape heterogeneity is undertaken with the help of landscape metrics computed using FRAGSTATS at class and landscape level, showing signs of increased fragmentation. Our study provides baseline database that can support the future biodiversity conservation and sustainable forest management initiatives.

The differential genetic signatures related to climatic landscapes for jaguars and pumas on a continental scale

Modern and paleoclimate changes may have altered species dynamics by shifting species’niche suitability over space and time.We analyze whether the current genetic structure and isolation of the two large American felids,jaguar(Panthera onca)and puma(Puma concolor),are mediated by changes in climatic suitability and connection routes over modern and paleoclimatic landscapes.We estimate species distribution under 5 climatic landscapes(modern,Holocene,last maximum glaciations[LMG],average suitability,and climatic instability)and correlate them with individuals’genetic isolation through causal modeling on a resemblance matrix.Both species exhibit genetic isolation patterns correlated with LMG climatic suitability,suggesting that these areas may have worked as“allele refuges.”However,the jaguar showed higher vulnerability to climate changes,responding to modern climatic suitability and connection routes,whereas the puma showed a continuous and gradual transition of genetic variation.Despite differential responsiveness to climate change,both species are subjected to the climatic effects on genetic configuration,which may make them susceptible to future climatic changes,since these are progressing faster and with higher intensity than changes in the paleoclimate.Thus,the effects of climatic changes should be considered in the design of conservation strategies to ensure evolutionary and demographic processes mediated by gene flow for both species.