Общие проблемы экологии. Размеры тела и размерные спектры

Общие проблемы экологии.

Размеры тела и размерные спектры.

Взаимосвязь размер тела – масштаб. Азовский.

Andrey I. Azovsky

Using original and literature data on species richness, I compared the species-area relations for 5 different size classes of the Arctic benthos: macrofauna sensu lato, polychaetes, nematodes, ciliates and diatom algae. The data pool covered a wide range of areas from single samples to the whole seas. Both the slopes and intercepts of the curves depended significantly on the logarithm of the mean body size of the group. The number of small species (ciliates and diatom algae) showed relatively higher local diversity but increased more slowly with the area than the number of larger ones. Thus, both - and -components of species diversity of the marine benthos were size-dependent. As a consequence, the actual relations between number of species and their physical size are spatially scale-dependent: there are many more species of smaller size classes in any one local community, but at a global scope the situation changes drastically. The possible reasons are discussed, including dispersal efficiency, rates of speciation and size-dependent perception of environmental heterogeneity. Body size is suggested to be the important scaling factor in manifestation of so-called general ecological laws.

Размерные спектры ручьевого бентоса

Авторы Tracey K. Stead, Jenny M. Schmid-Araya, Alan G. Hildrew

Журнал Freshwater Biology Год выпуска 2003 Дата март Том 48 Номер 3

Страницы 532-547 Статус

SUMMARY

1. The whole metazoan community (i.e. including the meiofauna) of an acidic, fishless stream in south-east England was surveyed over 14 months between March 1999 and April 2000. Invertebrate density, biomass and taxonomic richness were assessed on each sampling occasion in relation to physico-chemical variables.

. Целое metazoan сообщество (то есть включая meiofauna) кислого, fishless поток в юго-восточной Англии было рассмотрено более чем 14 месяцев между мартом 1999 и апрелем 2000. Бесхарактерная плотность, биомасса и таксономическое богатство были оценены в каждом случае осуществления выборки относительно физико-химических переменных.

2. Meiofauna были более многочисленные и разнообразные чем макрофауна, в то время как их полная биомасса иногда равнялась биомассе макрофауны.

3. Meiofaunal и макрофауновый assemblages, казалось, отвечали на различные экологические факторы. Meiofauna показал подлинный товарооборот разновидностей в течение года, в то время как макрофауна изменилась меньше по таксономическому составу, хотя были существенные изменения в плотности.

4. Эти данные предлагают, чтобы meiofauna и макрофауна существовали в различных временных и пространственных масштабах и чувствуют их окружающую среду с различным 'зерном'.

Бентос водотоков: размерная структура.

Source: JOURNAL OF THE NORTH AMERICAN BENTHOLOGICAL SOCIETY

2001, Vol 20, Iss 3, pp 421-431

We examined the temporal, longitudinal, and among-substrate

variation of the size structure of the invertebrate assemblage

in a Mediterranenan river (Aniene River, central Italy).

Sampling was conducted with quantitative methods on different

substrates every 2 mo at 2 sites for 1 y and at 9 additional

sites in spring 1997. Water-quality variables, periphyton

standing crop, and physical characteristics of sites were also

recorded. The Aniene River showed large longitudinal changes in

overall physical features, periphyton biomass, and water quality

that were reflected in dramatic changes of the taxonomic

composition of the invertebrate assemblage. Insects were

numerically dominant in the upper reach and codominant with

gastropods in the middle reach, whereas oligochaetes,

crustaceans, and chironomids were predominant in the lower and

polluted reach. Despite these changes, the shape of the size

structure of the invertebrate assemblage was similar among

sites, dates, and substrates, with limited departures from the

average size spectrum. Body mass alone accounted for the largest

part of the variance of the abundance per size class (48%)

whereas date, site, and substrate accounted for an additional

13%. These data support early observations of size spectrum

invariance from North American streams and rivers, reinforcing

the view that size-dependent processes may structure lotic

benthic assemblages.

Влияние размеров тела: грызуны.

Using body size to predict perceptual range

Stephen G. Mech and Patrick A. Zollner

We examined the relationship between body size and perceptual range (the distance at which an animal can perceive landscape elements) for a group of forest-dwelling rodents. We used previously published data on orientation ability at various distances for three sciurid species (gray squirrel, fox squirrel and chipmunk) and one murid species (white-footed mouse) to build a predictive model. We found a significant positive relationship between perceptual range and body mass. Although this model was built using a 15.5 m high horizon, we used this relation to predict the perceptual range of root voles (3.9-4.3 m) orienting towards a 0.5 m high horizon which was consistent with other empirical work suggesting a value of something less than 5 m. This model illustrates a relationship between perceptual range and body size and can be used to develop starting points for future investigations of perceptual range for similar organisms