Head form and climatic stress

Empiric evidence indicates that the general distribution of the cephalic index is explicable in terms of climatic adaptation. Based on a sample of 339 populations, the magnitude of the index is statistically different between zones of predominantly dry heat, wet heat, wet cold and dry cold. There is an inverse relationship between the mean cephalic index and temperature. It is argued that the occupation of cold climates is one of the circumstances increasing the frequency of brachycephaly through time.     

Long-term changes in the status of Sevastopol Bay and the Crimean coast: anthropogenic and climatic influences

The Black Sea as a whole is subject to considerable anthropogenic and natural pressures, and these can be intensified in enclosed Bays such as those around the city of Sevastopol. The overall biological status of Sevastopol Bay has improved considerably in the last 30 years or so. The number of macrobenthic species in the Bay has increased from just over 20 in 1973 to around 70 in 2000, and there have been similar enrichments in abundance, in biomass and in diversity (H′). The same pattern is shown in other locations such as the Southern Bay (the most highly polluted of the embayments) from which macrofauna were completely absent in 1976 and 1982. Over the same period oil hydrocarbons in sediments of the Southern Bay have actually increased from 8760 mg kg⁻¹ in 1976 to 12,020 mg kg⁻¹ in 2002, while the levels in the open sea sediments have decreased slightly over the same period (450 mg kg⁻¹ and 280 mg kg⁻¹, respectively). Moreover, this pattern of biological improvement is also seen outside the Bay, suggesting a common factor in the changes. Since the effect of the local factors (i.e. pollution) can be readily seen in the gradient of biological response among sites, yet they have not significantly changed over the period of study, the overall improvement must involve some over-arching driver such as climatic influences. This point is discussed further in relation to the wider changes in the Black Sea system. Guest editors: J. Davenport, G. Burnell, T. Cross, M. Emmerson, R. McAllen, R. Ramsay & E. Rogan Challenges to Marine Ecosystems     

Inter-specific synchrony of two contrasting ungulates: wild boar (Sus scrofa) and roe deer (Capreolus capreolus)

Very few studies on ungulates address issues of inter-specific synchrony in population responses to environmental variation such as climate. Depending on whether annual variation in performance of ungulate populations is driven by direct or indirect (trophic) interactions, very different predictions regarding the pattern of inter-specific synchrony can be derived. We compared annual autumn body mass variation in roe deer (Capreolus capreolus) and wild boar (Sus scrofa) from Poland over the period 1982–2002, and related this to variation in winter and summer climate and plant phenological development [the Normalized Difference Vegetation Index (NDVI), derived from satellites]. Roe deer fawns (∼1.3 kg increase from year 1982 to 2002) and yearlings both increased markedly in mass over years. There was also an increase for wild boar mass over years (∼4.2 kg increase for piglets from 1982 to 2002). Despite our failure to link annual body mass to spring or winter conditions or the NDVI, the body mass of roe deer and wild boar fluctuated in synchrony. As this was a field roe deer population, and since wild boar is an omnivore, we suggest this may be linked to annual variation and trends in crop structure (mainly rye). We urge future studies to take advantage of studying multiple species in order to gain further insight into processes of how climate affect ungulate populations. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.     

Assessing onset and length of greening period in six vegetation types in Oaxaca,Mexico, using NDVI-precipitation relationships

Variations in the normalized vegetation index (NDVI) for the state of Oaxaca, in southern Mexico, were analyzed in terms of precipitation anomalies for the period 1997-2003. Using 10-day averages in NDVI data, obtained from AVHRR satellite information, the response of six types of vegetation to intra-annual and inter-annual fluctuations in precipitation were examined. The onset and temporal evolution of the greening period were studied in terms of precipitation variations through spectral analysis (coherence and phase). The results indicate that extremely dry periods, such as those observed in 1997 and 2001, resulted in low values of NDVI for much of Oaxaca, while good precipitation periods produced a rapid response (20-30 days of delay) from a stressed to a non-stressed condition in most vegetation types. One of these rapid changes occurred during the transition from dry to wet conditions during the summer of 1998. As in many parts of the tropics and subtropics, the NDVI reflects low frequency variations in precipitation on several spatial scales. Even after long dry periods (2001-2002), the various regional vegetation types are capable of recovering when a good rainy season takes place, indicating that vegetation types such as the evergreen forests in the high parts of Oaxaca respond better to rainfall characteristics (timing, amount) than to temperature changes, as is the case in most mid-latitudes. This finding may be relevant to prepare climate change scenarios for forests, where increases in surface temperature and precipitation anomalies are expected.     

Variations in the tree-ring structure of Norway spruce (Picea abies) under contrasting climates

Variations in tree-ring structure from pith to bark of mature Norway spruce (Picea abies Karst. (L)) grown under contrasting climate conditions (warm-dry vs. cool-humid) in south-western Germany were investigated. Sample trees were from even-aged stands where no intensive silvicultural treatments had taken place. The cell number (CN), diameter (CD), lumen diameter (CL) and wall thickness (CW) were measured from stem cross-sections taken at breast height. A raw data chronology of each cell parameter was established for the whole annual ring (AR), earlywood (EW), latewood (LW), and transition wood (TW). The long-term trends of the cell parameters were generally non-linear, parameter-specific in AR and EW and similar over sites. Those in LW were site-specific and similar over cell parameters. The variation of the same parameter, expressed by the coefficient of variance (CV), tended to increase from EW towards LW and was clearly higher for CN than for other cell parameters of all tree-ring zones. Trees from the warm-dry site had more LW cells and substantially thicker CW, whereas those from the cool-humid site had larger EW cells. These observed differences are likely due to the hydraulic adaptation mechanisms of trees to different site conditions.     

Should avian egg size increase as a result of global warming? A case study using the red-backed shrike ( Lanius collurio)

From some life-history traits, avian egg size can be postulated as potentially affected by climate change. In this paper, we present and discuss the potential effect of mean temperature in the breeding season on egg size of the red-backed shrike (Lanius collurio). During the 1971–2002 study period, egg volume of the red-backed shrike decreased significantly, birds arrived at the breeding site significantly earlier, and arrival date was correlated with the earliest first egg date. To our knowledge, we present the first evidence that avian egg size decreased significantly in a long-term study. However, we do not have experimental manipulations in support of our data and we can only conclude that the decrease in egg volume in the studied population might result as a consequence of a number of factors, including changes in temperature, as well as in food supply. Therefore climate change effects on a birds life-history traits can be more complex than just the simple direct effect of temperature.Communicated by F. Bairlein     

A comparative study of satellite and ground-based phenology

Long time series of ground-based plant phenology, as well as more than two decades of satellite-derived phenological metrics, are currently available to assess the impacts of climate variability and trends on terrestrial vegetation. Traditional plant phenology provides very accurate information on individual plant species, but with limited spatial coverage. Satellite phenology allows monitoring of terrestrial vegetation on a global scale and provides an integrative view at the landscape level. Linking the strengths of both methodologies has high potential value for climate impact studies. We compared a multispecies index from ground-observed spring phases with two types (maximum slope and threshold approach) of satellite-derived start-of-season (SOS) metrics. We focus on Switzerland from 1982 to 2001 and show that temporal and spatial variability of the multispecies index correspond well with the satellite-derived metrics. All phenological metrics correlate with temperature anomalies as expected. The slope approach proved to deviate strongly from the temporal development of the ground observations as well as from the threshold-defined SOS satellite measure. The slope spring indicator is considered to indicate a different stage in vegetation development and is therefore less suited as a SOS parameter for comparative studies in relation to ground-observed phenology. Satellite-derived metrics are, however, very susceptible to snow cover, and it is suggested that this snow cover should be better accounted for by the use of newer satellite sensors.     

荒漠绿洲NDVI与气候、水文因子的相关分析

 通过利用1992～1996年NOAA/AVHRR逐旬的归一化植被指数（NDVI）数据和阜康气候、水文资料,分别对绿洲和荒漠进行了NDVI与气候、水文因子间的相关分析,得出了一些初步结论：绿洲与荒漠NDVI具有不同的季节变化规律;与绿洲NDVI相关显著的因子依次为气温、地下水位和降水,     

The UK Environmental Change Network after twenty years of integrated ecosystem assessment: Key findings and future perspectives

The UK Environmental Change Network (ECN), the UK's Long-Term Ecosystem Research (LTER) network, has now been operating for over twenty years. It was established in 1992 as a set of terrestrial sites at which sustained observations relevant to a range of ecological indicators and environmental parameters could be made. An additional ECN freshwater network was launched in 1994. In this paper we provide a brief history of the network, and describe its current structure and role within a complementary wider range of UK environmental monitoring and observation programmes that are either more focussed on specific parameters or habitats, or operate at different temporal and spatial scales. We then provide a review of the other papers within this Special Issue, which exemplifies the broad range of environmental concerns that ECN data and sites are helping to address. These include network-wide summaries of environmental and biological trends over the first two decades of monitoring, more site-specific assessment of the ecological impacts of local pressures resulting from changes in management, biological and ecosystem service indicator development, and the testing of new monitoring technologies. We go on to consider: (i) future directions of network development and adaptation in light of recently emerging environmental concerns, dwindling financial resources and the consequent need for greater efficiency; (ii) the desire for tighter integration with other monitoring and observation programmes both nationally internationally; (iii) opportunities raised by recent technological developments; and (iv) the need to process and make available data more rapidly to increase the capacity of ECN sites as early warning systems. In its first two decades of operation the ECN has accumulated a robust set of baseline data that describe environmental and biological variability across a range of habitats in unprecedented detail. With appropriate, informed development, these should prove invaluable in discerning the causes and consequences of environmental change for decades to come.     

Morgan's Canon: Is it still a useful rule of thumb?

For over 100 years, Morgan's Canon has served as the criterion for distinguishing what appears to be complex cognitive processes shown by animals from simpler associative learning processes (Pavlovian and instrumental conditioning). Morgan's ( 1894 ) canon states “In no case is an animal activity to be interpreted in terms of higher psychological processes if it can be fairly interpreted in terms of processes which stand lower in the scale of psychological evolution and development.” In the present article, several examples are provided in which complex human‐like processes are proposed to have been demonstrated but the judicious use of Morgan's Canon suggests that simpler mechanisms may be sufficient to account for the behavior. The use of Morgan's Canon is not meant to reduce behavior to its lowest common denominator but rather to challenge investigators to develop procedures that can distinguish between simple behavioral principles and the more complex processes that cannot be explained in terms of genetics or simple conditioning. Whatever the results of these experiments, they should help identify the underlying processes and mechanisms involved.