Faunal Analysis Research Articles

Climate and environment of a Pliocene warm world

The Pliocene Epoch, 5.33–2.58 million years ago (Ma), was a generally warmer and wetter interval with atmospheric CO 2-concentrations at or slightly above modern levels. This paper provides an overview of Pliocene vegetation, sea surface temperatures and climate modelling outcomes. Most prominent changes in Pliocene biome distribution compared to today include a northwards shift of temperate and boreal vegetation zones in response to a warmer and wetter climate as well as an expansion of tropical savannas and forests at the expense of deserts. Faunal analysis techniques and modelling experiments using the Hadley Centre climate model identified significantly higher Pliocene sea surface temperatures at mid and high latitudes of the northern hemisphere with cooling or unchanged sea surface temperatures at low latitudes. Global mean annual surface temperatures (MAT) are estimated to have been 2 to 3 °C higher during the Piacenzian (3.6–2.58 Ma) than today with a reduced equator to pole gradient. The marine realm during the Pliocene was characterised by a reconfiguration of ocean gateways, particularly the narrowing of the Indonesian Seaway and closure of the Central American Isthmus, which produced essentially a modern pattern of ocean circulation. In the Southern Ocean a warm early Pliocene gave way to late Piacenzian cooling. Proxy data indicate a reduced east to west sea surface temperature gradient in the tropical Pacific during the Pliocene warmth. The Pliocene is one of the most intensively studied geological intervals of the pre-Quaternary. No other warm period in the geological past yields such a unique combination of near modern atmospheric CO 2-concentrations, palaeogeography and palaeobiology. However, this paper also identifies data gaps and shortcomings in the reconstruction of Pliocene environments using proxy data and climate models on which future research should focus.

A ZOOARCHAEOLOGICAL SYNTHESIS OF SOUTH CAROLINA’S PREHISTORIC COASTAL SITES

A synthesis of faunal analyses from South Carolina’s prehistoric coastal sites is presented as a means of investigating geographic differences and diachronic changes attributable to climate. Thirty-one zooarchaeological samples from 26 sites are presented, ranging from the Late Archaic through the Late Mississippian periods. Frequencies of taxa such as eastern oysters, quahog clams, sea catfishes, and drums, among others, vary spatially and temporally, roughly paralleling broad climatic trends. These results, while preliminary, provide insight into faunal use patterns and are used to indicate avenues for future zooarchaeological research in South Carolina and surrounding areas.

Cross-platform program for likelihood-based statistical comparisons of mortality profiles on a triangular graph

The construction of mortality profiles to investigate age-at-death patterns is a typical component of most faunal analyses. While many methods exist for constructing and comparing mortality profiles, plotting the percentages of juvenile, prime, and old individuals on a triangular graph, or ternary diagram, remains a popular method for making comparisons. Typically, these comparisons are made visually, but because sample sizes are often small, any differences may be the product of sampling rather than meaningful contrasts in depositional history. To overcome this problem, here we present a likelihood-based method for making statistical comparisons of mortality profiles on a triangular graph, and we make available a cross-platform computer program that implements the method. Although we developed the method with mortality profiles in mind, in principle, it can be used to analyze any kind of artifact for which there are three distinct categories.

Not just cattle: Cranial perforations revisited

AbstractThe phenomenon of perforated cattle skulls is well known to archaeozoologists. It is a condition that has not only been reported during routine faunal analyses but, unusually for animal palaeopathological studies, it has also been the subject of dedicated research papers. A revolutionary moment in the understanding of this anomaly came with its detection in the skull of a European bison. As a result of this discovery, a developmental disorder of genetic origin is now accepted as the most probable cause. In this paper, it is suggested that the perforations are caused by a developmental disorder that is expressed during the pneumatisation of the frontal, parietal and occipital bones in animals with a large sinus frontalis. The first published example of this condition in pig supports this hypothesis. It is argued that the anomaly is a hereditary trait caused by a recessive gene, the phenotypic expression of which only appears in homozygous recessive individuals. Higher incidences of this condition in past cattle and pig populations in certain places at times, may therefore testify to the occurrence of population bottlenecks and/or inbreeding practices. Copyright © 2009 John Wiley & Sons, Ltd.

The impact of rapid early- to mid-Holocene palaeoenvironmental changes on Neolithic settlement at Nea Nikomideia, Thessaloniki Plain, Greece

The site of Nea Nikomideia is one of the oldest and most important Neolithic settlements in Northern Greece and the wider Balkan Peninsula, having been first occupied by early farmers at around 6500 cal. BC. Important archaeological excavations conducted in the 1960s suggested that the settlement was located close to an ancient coastline during the Neolithic. However, palaeoenvironmental change and landscape evolution in the vicinity of the site have seldom been considered in detail. Six cores from the western and central parts of the Thessaloniki Plain were therefore drilled in 2008 and subjected to palaeoenvironmental analyses, including sedimentology (LASER grain size and magnetic susceptibility measurements), chemical analysis (loss on ignition and carbonate content), stable isotopes analysis coupled with X-Ray diffraction measurements, molluscan faunal analysis and radiocarbon dating. The recognition of several important facies representing freshwater (lacustrine and fluvial) and brackish (lagoonal and marine-influenced) conditions have shed light on the environmental and landscape evolution of the western part of the Thessaloniki Plain and associated impacts on human occupation during the last 10,000 years. The general sequence proved in the cores indicates the predominance of lacustrine conditions during the early Holocene, with the occurrence of a marine transgression at c. 6000/5800 cal. B.C. This major palaeoenvironmental change corresponds with the 8.2 Ka event and is a likely cause for the desertion of Nea Nikomideia at that time. Subsequent regression of the shoreline to the east saw that the area around Nea Nikomideia returns to predominantly terrestrial conditions and the deposition of lacustrine and fluvial deposits.

Looking for problems: A systems approach to hominin palaeocommunities from Plio‐Pleistocene Africa

ABSTRACTThis paper evaluates the potential contribution(s) of faunal analysis to hominin palaeoecology at regional and continental scales, through an explicit investigation of the values, methods and conceptual frameworks of palaeoanthropology and their compatibility with real data structures. It employs a problem‐framing method developed in policy‐relevant science to establish a suitable research design for ‘large scale’ faunal analysis, before testing the method in a pilot study of 48 faunal assemblages from the African Plio‐Pleistocene. Hitherto, taphonomic bias has discouraged attempts to study faunal assemblages on large spatiotemporal scales, and most scientists have restricted their work to the smaller (site or local) scale and/or a subset of the total fauna. Furthermore, palaeoanthropological studies of fauna tend to address pre‐determined questions through analysis of statistical outputs (patterns), rather than investigating the limitations and potential of the data through exploratory work. This paper, despite identifying a number of inherent constraints on palaeocommunity analysis at the large scale—including a clear tendency towards the segregation of faunal assemblages along taphonomic and geographic lines—successfully defines palaeocommunities and identifies systematic variation in their distribution in several regional datasets and at the continental scale. It suggests that the potential viability of faunal analyses for a given project could be made empirically testable, and further work on the lines defined here might provide insight into the impacts of taphonomy and ecology at the large scale. Although there are conceptual and methodological problems associated with large‐scale faunal analyses, this paper suggests that they could provide some insight into hominin environments, evolutionary ecology and biogeography as part of a holistic, multi‐scale approach to our lineages' history. Copyright © 2010 John Wiley & Sons, Ltd.

Environmental Archaeology and Landscape Transformation at the Seventeenth-Century Ferryland Site, Newfoundland

From the 16th century onwards, English, Bretons, Basques, and Portuguese exploited the rich cod stocks of Newfoundland’s Grand Banks. Several permanent settlements in eastern Newfoundland were begun in the early 17th century, including the settlement at Ferryland (1621-1696). Planter families at Ferryland fished and welcomed seasonal fishing fleets, participating in a trade network that included the West Indies, New England, the Iberian Peninsula, the Mediterranean, and Great Britain. The colonization process brought about changes to the local environment due to both the intentional and unintentional importation of European plants and animals. The presence of a substantial percentage of nonnative plants and insects suggests that ballast dumping as well as the establishment of small cottage gardens contributed to the introduction of several species to Newfoundland. Data from archaeobotanical, archaeoentomological, and faunal analyses can be used to examine processes of biological transfer, landscape change, and development of local household economies of Ferryland residents.

Large-scale patterns in marine harpacticoid (Crustacea, Copepoda) diversity and distribution

The zoogeographic distributions of 1,747 species of shallow-sea benthic Harpacticoida from 370 genera and 51 families reported in the Northern Hemisphere (Atlantic and Arctic Oceans and the European seas) were analyzed. Faunal diversity analysis revealed that the Northeast Atlantic and the North and Mediterranean Seas contain the richest faunas, while certain Arctic regions and internal seas (Caspian, Azov and Aral Seas) are the poorest ones. The distribution of families and genera was also briefly analyzed. Most families are widely distributed (probably cosmopolitan), though others are restricted to boreo-subtropical or even tropical zones, and no purely Arctic families were discovered. Many more genera are present in (or even restricted to) the tropics/subtropics compared with the Arctic/Subarctic zone. Over 15% of species and 55% of genera can be still considered either widespread or cosmopolitan. Cluster-analysis of the regions by species composition revealed six main clusters: Arctic (central Arctic basin, Kara, Laptev, East Siberian, Chukchi and Beaufort Seas), Boreal (North Atlantic Ocean, and North, Baltic, White and Barents Seas), Mediterranean, Ponto-Caspian (Black, Azov, Caspian and Aral Seas), Central East Atlantic, and Central West Atlantic. The distinction between the Mediterranean and Ponto-Caspian faunas is considered in particular, as the latter is not an exact derivative of the Mediterranean one but instead has more atlanto-boreal features. The percent of regional endemics, mean species occurrence and number of families correlate with total species richness, which primarily reflects the degree of exploration in a given region. After removing this effect, the abovementioned features show significant latitudinal trends, with a few endemics present in polar waters. The distribution patterns of different life-forms also vary according to their dispersal abilities. At both global and regional scales, bentho-pelagic forms are the most widely distributed, followed by phytal species, whereas benthic species, especially interstitial, have a more restricted distribution. Overall, our results confirm and statistically validate the main features of marine harpacticoid biogeography asserted a quarter of a century ago by Abele [In: Abele LG (ed) The biology of crustacea. Academic Press, New York, pp 242–304, 1982] and Wells (Syllogeus 58:126-135, 1986).

Long-term effect of fertility management on the soil nematode community in vegetable production under greenhouse conditions

Nematode trophic groups and functional guilds were monitored after long-term fertilization regimes in a vegetable greenhouse, where no fertilizer, organic manure, two different levels of inorganic fertilizers and the combined applications of manure with different levels of inorganic fertilizers were compared. Significant treatment effects were observed in the abundance of total nematodes and the composition of different trophic groups. Compared with other fertilizer treatments, manure fertilizer increased the abundance of total nematodes, and the relative abundance of bacterivores, while the relative abundance of plant parasites decreased. The relative abundance of plant parasites and fungivores increased, and that of bacterivores decreased following the applications of N fertilizer in July. High levels of nitrogen fertilizer decreased the relative abundance of omnivore–carnivores. The values of the basal index and channel index decreased in the treatments with manure and increased following the N fertilizer compared to the control. Nematode faunal analysis indicated that soil food webs in the treatments with manure were disturbed, and those in the treatments with inorganic fertilizers were degraded due to the relatively lower soil pH and higher electrical conductivity induced by the high level of nitrogen fertilization.

The cicada fauna of Pakistan including the description of four new species (Hemiptera: Cicadoidea: Cicadidae)

The first faunal analysis of the cicadas of Pakistan is provided. Field work and museum study has added significantly to the known cicada fauna of Pakistan. Literature records provide evidence for 18 species inhabiting what is currently Pakistan. The first records of Platypleura basialba (Walker), Platypleura mackinnoni Distant, Cicadatra persica Kirkaldy, Cicadatra xantes (Walker), Meimuna velitaris (Distant), Haphsa nicomache (Walker), and Paharia putoni (Distant) are provided. Psalmocharias balochii sp. n., Psalmocharias chitralensis sp. n., Psalmocharias gizarensis sp. n. and Psalmocharias japokensis sp. n. are described as new. These are the first records of members of the genera Meimuna Distant and Haphsa Distant in Pakistan. The new records and new species represent a 61% increase in faunal diversity. The cicada fauna of Pakistan now comprises of a total of 29 species from 13 genera, five tribes and three subfamilies. These data provide a more accurate understanding of cicada diversity at the junction of the Oriental and Palaearctic regions.

Late Cambrian brachiopods from Jingxi, Guangxi Province, South China

The brachiopod fauna of the upper Cambrian (upper Furongian) Guole Formation, northwestern Jingxi County, southwestern Guangxi Province, southern China, comprises six genera and seven species, including one new genus, three new species and two indeterminate species (Obolidae gen. et sp. indet, Acrotretidae gen. et sp. indet., Billingsella guangxiensis, B. costata sp. nov., Guoleella lata gen. et sp. nov., Palaeostrophia jingxiensis, Plectotrophia imparicostata sp. nov.). This is the first systematic description of an upper Cambrian brachiopod fauna composed mainly of calcareous-shelled individuals from China. Brachiopod and trilobite faunal analyses suggest that this fauna has a prominent North American (Laurentian) affinity. It is notably different from the coeval, lingulate-dominated brachiopod fauna of South China, particularly of the Yangtze Platform, but shares some similarity with those of the North China Platform. Preliminary analysis reveals that this brachiopod fauna, named the Billingsella-Palaeostrophia Fauna, lived in a nearshore, shallow water benthic regime with a calcareous muddy substrate.

Reconstruction of deep-water conditions in the North Atlantic during MIS 9 based on benthic foraminiferal assemblages

Marine isotope stage (MIS) 9 is one of the least investigated Pleistocene interglaciations. The present study describes reconstructions of deep-water conditions during this time interval based on benthic foraminiferal assemblages from sediment core M23414 (Rockall Plateau, North Atlantic). The results of faunal analysis were supported by planktic δ18O, sea surface temperature reconstructions based on planktic foraminiferal assemblages and content of ice rafted debris. Statistical data processing using principal component analysis revealed five climate-related benthic foraminiferal associations that changed in response to alterations of deep-water circulation.

Faunal and biogeographic analysis of Syllidae (Polychaeta) from Rovinj (Croatia, northern Adriatic Sea)

Luigi MuscoThe study of hard-bottom Syllidae (Polychaeta) of the Rovinj area provides an updated measure of syllid species diversity in the northern Adriatic Sea. Faunal research in the coldest Mediterranean sectors may also help to address possible ecological and biogeographical consequences arising from climate change. Thirty-nine species were found, of which 13 are new for the northern Adriatic, increasing the species recorded from the area from 53 to 66. Some newly recorded species are dominant and typical of warmer areas. The lack of previous taxonomic updates is responsible for the high number of new findings. However, the northern Adriatic Sea is possibly undergoing long-term changes, with modifications of diversity due to the establishment of warm-water species. Syllid fauna of Sveti Ivan Island and its bioclimatic affinity are, in fact, unexpectedly more similar to the ones of some southern Mediterranean areas than to those traditionally reported for the northern Adriatic.

Paleoenvironment of Ankilitelo Cave (late Holocene, southwestern Madagascar): implications for the extinction of giant lemurs

Following human arrival, Madagascar suffered well-documented megafaunal extinctions and widespread deforestation. Although humans are widely considered to be the primary cause of the extinctions, the relative contributions of climate change and human activities to this ecological transformation remain uncertain. Reconstructing the habitats of the giant lemurs of Madagascar can provide key information for understanding the evolutionary mechanisms involved in their extinction. In this study, I present a faunal analysis of the subfossil assemblage from Ankilitelo Cave, southwestern Madagascar. This assemblage documents the latest known occurrence of five species of extinct giant lemur, in association with abundant well-preserved small mammal remains. I compared the small mammal fauna at Ankilitelo with 27 extant Malagasy mammal communities spanning the range of Madagascar's habitat types. Similarities in species composition between modern communities and Ankilitelo were assessed using cluster analysis. Ecological similarities were examined by assigning each species to dietary, locomotor, activity pattern, and body size categories. Multiple discriminant analysis was then used to classify Ankilitelo relative to modern habitat types in Madagascar, based on the ecological structure of the subfossil fauna. Results indicate that the habitat surrounding Ankilitelo during the late Holocene was similar to the succulent woodlands of modern southwestern Madagascar. This suggests that approximately 500 yr BP, these semi-arid habitats supported a subfossil lemur community that included the highly-suspensory Palaeopropithecus, and deliberate slow-climber Megaladapis, as well as Archaeolemur, Pachylemur, and Daubentonia robusta. In such environments, these giant lemurs would likely have been highly vulnerable to increasing human pressure in southwestern Madagascar.

Spatial Distribution of Soil Nematode Communities in Stable and Active Sand Dunes of Horqin Sandy Land

To explore the ecological significance of artificial plantation and the restoration process in sand dune ecosystems, the spatial distribution of soil nematode communities in stable and active sand dunes were investigated in northeastern Inner Mongolia, China. Soil nematode community structure and composition at five soil depths (0–5 cm, 5–10 cm, 10–20 cm, 20–40 cm, and 40–60 cm) and three slope positions (windward slope, top slope, and leeward slope) in the stable and active sand dunes were compared. The results showed that the total abundance of soil nematodes decreased with increasing soil depth in the stable sand dune, while increasing in the active sand dune. Bacterivores were found to be the most abundant group in both the stable and active dunes. Significant depth effects were found in the four nematode trophic groups. Thirty-eight and 29 genera were observed in the stable and active sand dunes, respectively. Acrobeles was dominant genus in the stable sand dune, while Acrobeloides was most prevalent in the active sand dune. The increasing values of generic diversity, evenness, and species richness, and the decreasing trend of the Simpson index from 0–5 cm to 20–40 cm were found in the stable sand dune. Nematode faunal analysis indicated that the soil food web in the stable sand dune was barely disturbed in comparison to the active sand dune. The positive interfeedback between soil and vegetation was the key to restoring the sandy ecosystems. Soil nematode communities can be used as bioindicators for assessing the rehabilitation of the sand dune ecosystems.

Late-Holocene evolution of a coastal lagoon in the Gulf of Lions (South of France)

Abstract The central part of the Gulf of Lions shoreline is characterized by many coastal wetlands that resulted from the interaction between a process of shoreline regularization by migrations of littoral barriers and a slow filling of the back-barrier areas by the riverine and marine inputs. Analyses of Late-Holocene deposits with a very high-resolution multi-proxy study of two sediment cores, allow us to reconstruct the evolution of this coastal system. Two main Holocene sediment units are identified overlying a Pliocene carbonate continental formation. The lower unit consists of sandy and pebbly marine sediments deposited around 7800 B.P., during the final stand of the last sea level rise. Just above, the upper unit displays lagoonal grey clay silts with shells and some intercalated layers of silty sands related to paleostorm events. The age model was established from radiocarbon dating, for the oldest part of the core. Over the last century, sedimentation rates were calculated using the CFCS 210Pb model, together with 137Cs data. Radiocarbon data show an increase in the accumulation rate from the base to the top of cores. Marine sand units related to the last transgressive deposit allow to refine the curve of Holocene post-glacial sea level rise. Sedimentological and faunal analyses associated with chronological data provide a means for reconstructing the Late-Holocene paleoenvironments along this part of the coast and suggest that the final closure of the coastal lagoon by the sandy barrier occurred at around 730 ± 120 yr cal B.P. The beginning of this closure, together with the progradation of the coastal plain, could be responsible for the decline in economic activity of the Lattara harbour during the Roman period.

The Homo sapiens Cave hominin site of Mulan Mountain, Jiangzhou District, Chongzuo, Guangxi with emphasis on its age

One of the most hotly debated and frontal issues in paleoanthropology focuses on the origins of modern humans. Recently, an incomplete hominin mandible with a distinctly weaker mental protuberance than modern human and a great variety of coexisting fossil mammals were unearthed from the Homo sapiens Cave of Mulan Mountain, Chongzuo, Guangxi. The mammalian fauna from the Homo sapiens Cave characterized by the combination of Elephas kiangnanensis, first occurring Elephas maixmus, and Megatapirus augustus, and strikingly different from the Early Pleistocene Gigantopithecus fauna and the Middle Pleistocene Ailuropoda-Stogodon fauna of South China could be regarded as an early representive of the typical Asian elephant fauna. Faunal analysis, biostratigraphic correlation, and, most importantly, U-series dating all consistently support an estimate of ca. 110 ka for the age of the fossil Homo sapiens and coexisting mammalian fauna, that is, the early Late Pleistocene. The fauna is mainly made up of tropical-subtropical elements, but grassland elements have a much greater variety than forest elements, which probably indicates a drier climate at that time. This discovery of early Homo sapiens at the Mulan Mountain will play a significant role in the study of the origin and its environmental background of modern humans.

The herpetofauna of Sonora, Mexico, with comparisons to adjoining states

Situated in the topographically complex transition between the Neotropics and the temperate biomes of North America, the state of Sonora, Mexico, has an extraordinarily diverse herpetofauna. Surprisingly little research has been conducted on the state’s amphibians and reptiles and many systematic and biogeographic questions remain unanswered. To facilitate future research, we provide a checklist of Sonora’s herpetofauna, documenting species presence based on museum specimens, our fieldwork, and published research. Sonora’s herpetofauna is placed in a regional biogeographic perspective via a checklist for the six adjoining states together with faunal analyses. A total of 402 species of amphibians and reptiles are recorded from these seven states. Sonora has the greatest species richness (187 species), followed by Chihuahua (169 species), and Sinaloa (146 species). Sonora's herpetofauna is most similar to that of Chihuahua, with which it shares a long border. Eleven biogeographic affinity-based faunal groups are recognized. Of these, three are dominant in Sonora: a core group classified as "Sonoran" demonstrates strong affinity to Sonoran Desertscrub and Sinaloan Thornscrub communities; a Tropical group - with many species reaching their northern distributional limits in the state; and a Madrean group consisting largely of montane species. Our state-level faunal analysis provides some evidence of peninsular depauperization of the herpetofauna on the Baja California peninsula due in part to the small number of Neotropical species present in Baja California Sur. Our faunal analysis points toward distinctive mainland and peninsular Sonoran Desert herpetofaunas centered on Sonora and the Baja California Peninsula, respectively, each with about 50 non-insular species, and each with species-level endemism nearing 50%.

Hard- and soft-bottom thanatofacies from the Santa Maria di Leuca deep-water coral province, Mediterranean

Thanatofacies and the skeletonized components of the living facies, from which they originate have been studied from the Santa Maria di Leuca (SML) deep-water coral mound province. Faunal analysis was carried out by means of bottom sampling and underwater video observations, taking into account all benthic taxonomic groups, mostly corals, molluscs, serpulids, bryozoans, ostracods, foraminifers and barnacles, which permitted recognition of six different facies. These thanatofacies are easily distinguishable and appear to be largely corresponding and overlapping with related living facies. Some occur in mound areas, others in the intermound ones. They are as follows: the Framework-building Coral facies (FC), characterised by colonial corals, mostly Madrepora oculata; the Coral Rubble facies (CR), with proximal and distal aspects, characterised by large- to small-sized and densely to loosely packed coral fragments; the Solitary Coral facies (SC), dominated by different species depending on the availability and dimensions of hard exploitable surfaces; the Gryphus and Isidella facies (GI) in relatively coarse-grained bottoms; the Mollusc Mud facies (MM) and the Foraminifer Mud facies (FM) in comparably homogeneous silty bottoms. Facies distribution and spatial variability are discussed, in relation to hydrology and sea-floor topography. Furthermore, the SML facies are compared with living facies from the present-day Mediterranean and Pleistocene sediments of the same area. Data on bioclastic assemblages can serve for comparison with other recent aphotic, non-tropical carbonates.

Nematode Diversity in Phaeozem Agroecosystems of Northeast China

The diversity and distribution patterns of soil nematode communities in phaeozem agroecosystems of Northeast China were assessed to evaluate nematode taxonomic diversity and functional diversity in relation to climatic condition and soil characteristics in human modified landscape. Along the latitudinal gradient, soil samples were collected from north (Hailun) to south (Gongzhuling) down to a depth of 100 cm with intervals of 0–20, 20–40, 40–60, 60–80, and 80–100 cm. The nematode abundance and taxonomic diversity (generic richness) were lower at Hailun than at other sites, and higher values of evenness were observed at Hailun and Harbin than at Dehui and Gongzhuling. Nematode faunal analysis revealed that soil food web at Hailun was successionally more mature or structured, and the environment little disturbed, while at Harbin and Gongzhuling, the soil food web was degraded with stressed environment. The environmental variables relevant in explaining the patterns of nematode distribution and diversity in phaeozem agroecosystems, using canonical correspondence analysis (CCA), were the mean annual temperature, total nitrogen, electrical conductivity, mean annual precipitation, and other soil properties. Among these variables, the mean annual temperature was a relatively important factor, which could explain 29.05% of the variations in nematode composition.