How is adaptation to climate change reflected in current practice of forest management and conservation? A case study from Germany

Climate change is expected to challenge forest management and nature conservation in forests. Besides forest species, strategies and references for management and conservation will be affected. In this paper, we qualitatively analysed whether forest conservation and management practice have already adapted to the impacts of climate change and to what extent those practices reflect the adaptation strategies dealt with in international peer-reviewed literature. To this end, we conducted thirteen in-depth interviews with forest practitioners (forest officers/forest district officers) in four regions in Germany. The interview regions were selected to represent the variation in tree species composition, forest ownership regimes and vulnerability to climate change. Although interviewees claimed to take climate change and adaptation strategies into account, in practice such strategies have as yet only occasionally been implemented. Our results suggest that strategies for adapting forest management to climate change are just in the early stages of development or supplement existing strategies relating to general risk reduction or nature-orientated forest management. The extent to which climate change adaptation strategies have influenced overall management varies. This variation and the lack of specific strategies also reflect the existing uncertainties about future changes in climate and about the capacity of forest ecosystems to adapt. We conclude that, in the face of climate change, forest management will have a major influence on future biodiversity composition of forest ecosystems. Hence, a framework for conservation in forests providing recommendations which also take into account the consequences of climate change needs to be developed.     

Responses to low salinity by the sea star Pisaster ochraceus from high‐ and low‐salinity populations

Abstract. In many coastal environments, variation in salinity and organismal responses to that variation are important determinants of the distribution and abundance of species. This study examined the effects of acute salinity changes on sea stars (Pisaster ochraceus) collected from a high‐salinity site (Bamfield, BC) and a low‐salinity site (Vancouver, BC). Sea stars from both sites were exposed to salinities ranging 15–30 psu. Following a 24‐h exposure, the osmolality, sodium concentrations, and chloride concentrations in the perivisceral fluid all varied directly with salinity and were very close to the treatment salinities in both the Bamfield and Vancouver sea stars. The righting response (measured as an activity coefficient) was salinity dependent, with the lowest activity levels at a salinity of 15 psu. Activity coefficients did not vary between the two source populations. Feeding rates on mussels were strongly salinity dependent, but the salinity pattern was population specific. Bamfield sea stars fed the most at 30 psu, whereas Vancouver sea stars fed the most at 20 psu. High post‐experimental mortalities were observed in Bamfield sea stars that had been exposed to a salinity of 15 psu; no such mortality was observed in Vancouver animals. This study provides evidence that the sea stars from the lower salinity environment had been able to acclimatize or adapt to low‐salinity conditions. However, the results also suggest that there are limits to this tolerance, and that future changes in salinity may have important consequences for marine communities via alteration of keystone predation.     

Memory decay and susceptibility to amnesia dissociate punishment- from relief-learning

Painful events shape future behaviour in two ways: stimuli associated with pain onset subsequently support learned avoidance (i.e. punishment-learning) because they signal future, upcoming pain. Stimuli associated with pain offset in turn signal relief and later on support learned approach (i.e. relief-learning). The relative strengths of such punishment- and relief-learning can be crucial for the adaptive organization of behaviour in the aftermath of painful events. Using Drosophila, we compare punishment- and relief-memories in terms of their temporal decay and sensitivity to retrograde amnesia. During the first 75 min following training, relief-memory is stable, whereas punishment-memory decays to half of the initial score. By 24 h after training, however, relief-memory is lost, whereas a third of punishment-memory scores still remain. In accordance with such rapid temporal decay from 75 min on, retrograde amnesia erases relief-memory but leaves a half of punishment-memory scores intact. These findings suggest differential mechanistic bases for punishment- and relief-memory, thus offering possibilities for separately interfering with either of them.     

EMG modulation in anticipation of a possible trip during walking in young and older adults.

This study investigated whether changes in lower limb muscle activity occurred in anticipation of a possible perturbation in 11 young (mean age 27 years) and 11 older (mean age 68 years) adults. Altered muscle activity could affect tripping responses and consequently the ecological validity of experimental results of studies on tripping. It was hypothesized that anticipatory muscle activity would be present immediately after a trip, and decrease after several subsequent unperturbed (forewarned) walking trials. Electromyograms of lower limb muscles were measured in 3 conditions: during normal walking, during forewarned walking immediately after a trip, and during forewarned walking several trials after a trip had occurred. Small but statistically significant differences in averaged muscle activity over a stride were found among conditions. Young adults showed slightly increased activity immediately after tripping (co-contraction) in hamstrings, quadriceps and tibialis anterior muscles. This increased activity diminished after several unperturbed trials, although it did not return to the baseline activity levels during normal walking. In older adults, an increased muscle activity among conditions was only discerned in tibialis anterior and soleus muscles. This suggested that older adults prefer to avoid contact with the obstacle over joint stiffening. Yet, for both age-groups, the increases in muscle activity were very small when compared to tripping responses reported in the literature. Therefore, anticipatory effects are not expected to jeopardize the validity of experiments in which subjects are perturbed more than once.