Habitat preferences of some red‐listed alpine plants in Scandinavia

Scandinavian alpine vascular plants are red‐listed (R‐L) according to criteria defined by IUCN. These are based on an evaluation of their risk for extinction in the future, which for most alpine plants have been related to possible effects of climate change. In the present study, ecological characteristics of R‐L alpine plants are inferred from their occurrence in previously studied alpine plant communities. In total, data on 231 communities were compiled from studies in Norway and Sweden, and a total of 39 red‐listed vascular plants were found in 142 of them. The data were analysed by numerical analyses in order to assess if and how communities with and without R‐L species differ in terms of floristic composition and environmental conditions. The analysies show that most of the R‐L plants are situated at the ends of the main floristic gradients extracted by Detrended Correspondense Analysis (DCA). These extremes are interpreted to represent high‐altitudinal communities with long‐lasting snow cover. In productive communities dominated with herbs and ferns, R‐L plants are few or missing. A Principal Components Analysis (PCA) indicated that the R‐L species form a heterogeneous group both in terms of ecology, abundance, and geographic distribution. Some of the communities were considered to be especially valuable because they included several (up to eight) R‐L plants. Such communities are found in the upper part of the middle alpine or high alpine zone (460–675 m above the forest limit) and on calcareous substrate. It may generally be assumed that alpine plants with optima at the edges of the floristic gradients may be especially vulnerable to climate changes.     

Frond development and phenology of Thelypteris limbosperma, Athyrium distentifolium, and Matteuccia struthiopteris in Western Norway

Odland, A. 1995. Frond development and phenology of Thelypteris limbosperma, Athyrium distentifolium, and Matteuccia struthiopteris in Western Norway. — Nord. J. Bot. 15: 225–236. Copenhagen. ISSN 0107–055X. The pattern of growth and phenology of Thelypteris limbosperma, Athyrium distentifolium, and Matteuccia struthiopteris fronds has been investigated, with particular emphasis on height increments of the sporophytes and the development of fertile fronds. In order to study both interspecific and intraspecific differences, fern stands along altitudinal gradients have been monitored. To investigate the initiation of fertility, fronds representing different developmental stages have been sampled. Climatic data have been collected with a data-logger during the study periods. The ferns show significant differences in growth pattern and phenology. Matteuccia struthiopteris has a growth curve that is best described as monomolecular, characterised by high growth rates during the early developmental stage, while the development of Thelypteris limbosperma and Athyrium distentifolium follow a logistic growth curve. The species need different periods of time to develop their fronds. The main frond elongation does not start before soil temperature has reached 7 C. After that, the growth is mainly controlled by air temperature. Within the interval when mean maximum temperatures are 8–20 C, all three ferns showed increased growth rates with increasing air temperatures, but the increase was greatest in M. struthiopteris. At higher temperatures, the growth rate of M. struthiopteris and T. limbosperma decreased. Athyrium distentifolium is characterised by producing sori at an early developmental stage. Fertile Matteuccia strurhiopteris fronds are developed at a much later developmental stage. Thelypteris limbosperma needs a longer period of time to produce mature fronds than the other species. The investigation indicates that plant growth and development are determined by both internal and external factors. It is concluded that growth rate, phenology, and the ability of ferns to produce mature fronds reveal close similarities with their response to environmental variables, and hence with their broad-scale geographical distributional patterns.     

Neue diterpene und germacranolide aus Mikania-Arten

From three Mikania species, three new labdanic acid and two kaurenic acid derivatives have been isolated together with known compounds and four new germacranolides, differing only in the ester moiety.     

What Is Secondary about Secondary Tropical Forest? Rethinking Forest Landscapes

Forests have long been locations of contestation between people and state bureaucracies, and among the knowledge frameworks of local users, foresters, ecologists, and conservationists. An essential framing of the debate has been between the categories of primary and secondary forest. In this introduction to a collection of papers that address the questions of what basis, in what sense, and for whom primary forest is ‘primary’ and secondary forest is ‘secondary,’ and whether these are useful distinctions, we outline this debate and propose a new conceptual model that departs from the simple binary of primary and secondary forests. Rather, we propose that attention should be given to the nature of the disturbance that may alter forest ecology, the forms of regeneration that follow, and the governance context within which this takes place.

     

Local temperatures inferred from plant communities suggest strong spatial buffering of climate warming across Northern Europe

Recent studies from mountainous areas of small spatial extent (<2500 km²) suggest that fine‐grained thermal variability over tens or hundreds of metres exceeds much of the climate warming expected for the coming decades. Such variability in temperature provides buffering to mitigate climate‐change impacts. Is this local spatial buffering restricted to topographically complex terrains? To answer this, we here study fine‐grained thermal variability across a 2500‐km wide latitudinal gradient in Northern Europe encompassing a large array of topographic complexities. We first combined plant community data, Ellenberg temperature indicator values, locally measured temperatures (LmT) and globally interpolated temperatures (GiT) in a modelling framework to infer biologically relevant temperature conditions from plant assemblages within <1000‐m² units (community‐inferred temperatures: CiT). We then assessed: (1) CiT range (thermal variability) within 1‐km² units; (2) the relationship between CiT range and topographically and geographically derived predictors at 1‐km resolution; and (3) whether spatial turnover in CiT is greater than spatial turnover in GiT within 100‐km² units. Ellenberg temperature indicator values in combination with plant assemblages explained 46–72% of variation in LmT and 92–96% of variation in GiT during the growing season (June, July, August). Growing‐season CiT range within 1‐km² units peaked at 60–65°N and increased with terrain roughness, averaging 1.97 °C (SD = 0.84 °C) and 2.68 °C (SD = 1.26 °C) within the flattest and roughest units respectively. Complex interactions between topography‐related variables and latitude explained 35% of variation in growing‐season CiT range when accounting for sampling effort and residual spatial autocorrelation. Spatial turnover in growing‐season CiT within 100‐km² units was, on average, 1.8 times greater (0.32 °C km^?1) than spatial turnover in growing‐season GiT (0.18 °C km^?1). We conclude that thermal variability within 1‐km² units strongly increases local spatial buffering of future climate warming across Northern Europe, even in the flattest terrains.     

Seasonal variation in the frequency of abnormal anaphases and mitotic index values in wild populations of herb-Paris (Paris quadrifolia L., Trilliaceae): implications for genetic monitoring

The main aim of our study was to investigate seasonal variation in the frequency of abnormal anaphases and mitotic index values in wild populations of herb-Paris (Paris quadrifolia L., Trilliaceae). Plant material was collected in the year 2000 in Norway and in the year 2001 in Lithuania. There was statistically significant variation in the mitotic index values (chi(2)=1087.9, d.f.=16, P<0.0001) with the highest values during the active growth period in May and the lowest values at the end of vegetation period in September. Seasonal variation in the frequency of abnormal anaphases was statistically significant as well (chi(2)=28.23, d.f.=16, P=0.0297). The most frequent type of anaphase abnormality was vagrant chromosomes (64.2%) followed by bridges (28.6%), fragments (3.6%), sticky chromosomes (2.4%) and multipolar anaphases (1.2%). During the fieldwork, quite deep late frosts occurred. Mitotic index was lower in the plants collected immediately after the frosts or 1 week later than in the plants sampled before the frosts (52+/-13 and 123+/-15, respectively, P=0.0014). On the contrary, frequency of abnormal anaphases was statistically significantly elevated (P=0.0082) in plants after the frosts (6.35+/-1.54%) when compared to plants before the frosts (2.49+/-0.56%). Our results clearly indicated significant variation in the mitotic index values and frequency of abnormal anaphases in the wild populations of herb-Paris during the growth season. This variation may be related to the physiological conditions of the analysed plants as well as to certain ecological factors.     

Cyclooxygenase-1 and cyclooxygenase-2 expression in rat kidney and adrenal gland after stimulation with systemic lipopolysaccharide

Cyclooxygenase-2 (COX-2) is a recently discovered isoform of cyclooxygenase that is inducible by various types of inflammatory stimuli. Although this enzyme is considered to play a major role in inflammation processes by catalyzing the production of prostaglandins, the precise location, distribution, and regulation of prostaglandin synthesis remains unclear in several tissues. Using in situ hybridization histochemistry, we investigated the induction of COX-1 and COX-2 mRNA expression after systemic administration of a pyrogen, lipopolysaccharide (LPS), in kidney and adrenal gland in the rat. The COX-2 mRNA signals dramatically increased 1 h after LPS treatment in the kidney outer medulla and adrenal cortex, where almost no or little expression was observed in nontreated animals, and returned to control levels within 24 h. COX-2 mRNA levels increased in the kidney inner medulla 6 h after treatment. There was also a significant increase in mRNA levels in the kidney cortex and adrenal medulla. On the other hand, COX-1 mRNA levels did not show any detectable changes except in the kidney inner medulla, where a significant downregulation of mRNA expression was observed after LPS treatment. Light and electron immunocytochemistry using COX-2 antibodies showed that strong COX-2 immunoreactivity was localized to certain cortical cells of the thick ascending limb of Henle. In addition, based on double-staining with antiserum to nitric oxide synthase (NOS) four further cell populations could be identified in kidney cortex, including weakly COX-2-positive, NOS-positive macula densa cells. After LPS treatment, changes in COX-2 immunoreactivity could be observed in interstitial cells in the kidney medulla and in inner cortical cells in the adrenal gland. These results show that COX-2 is a highly induced enzyme that can be up-regulated in specific cell populations in kidney and adrenal gland in response to inflammation, leading to the elevated levels of prostaglandins seen during fever. In contrast COX-1 mRNA levels remained unchanged in this experimental situation, except for a decrease in kidney inner medulla.     

Real or Artificial? Intergroup Biases in Mind Perception in a Cross-Cultural Perspective

Recent research suggests that attributions of aliveness and mental capacities to faces are influenced by social group membership. In this article, we investigated group related biases in mind perception in participants from a Western and Eastern culture, employing faces of varying ethnic groups. In Experiment 1, Caucasian faces that ranged on a continuum from real to artificial were evaluated by participants in the UK (in-group) and in India (out-group) on animacy, abilities to plan and to feel pain, and having a mind. Human features were found to be assigned to a greater extent to faces when these belonged to in-group members, whereas out-group faces had to appear more realistic in order to be perceived as human. When participants in India evaluated South Asian (in-group) and Caucasian (out-group) faces in Experiment 2, the results closely mirrored those of the first experiment. For both studies, ratings of out-group faces were significantly predicted by participants’ levels of ethnocultural empathy. The findings highlight the role of intergroup processes (i.e., in-group favoritism, out-group dehumanization) in the perception of human and mental qualities and point to ethnocultural empathy as an important factor in responses to out-groups.