scholarly journals The gall maker Neopelma baccharidis Burck. (Homoptera:Psyllidae) on Baccharis dracunculifolia DC. (Asteraceae): individual, local, and regional patterns

1997 ◽  
Vol 26 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Rosane G. Collevatti ◽  
Carlos F. Sperber
Keyword(s):  
Host Plant ◽  
Regional Scale ◽  
Plant Size ◽  
Individual Plant ◽  
Regional Patterns ◽  
Frequency Distributions ◽  
Crown Volume ◽  
Minas Gerais State ◽  
Local Plant ◽  
Local Host

Baccharis dracunculifolia, the host plant of the gall maker Neopelma baccharidis Burck., is locally distributed in delimited patches. The effects of the host plant individual (plant height, crown diameter, and crown volume), local (host plant patch), and regional (locality) characteristics on the number of galls were analyzed, in Viçosa (three patches) and in Rio Doce State Park, Marliéria (two patches), Minas Gerais State (20°45'S, 42°50'W; and 19°50'S, 42°30'W, respectively). The number of galls/individual plant increased homogenousliy with plant dimensions on local and regional scale. Gall load was also homogenous, but the proportion of galled plants differed on a local scale. The differences were related to local plant size differences, and not to host plant patch size. Plants without galls presented different frequency distributions of plant dimensions than galled plants, with greater number of little plants, which indicated a minimum plant size to be gall maker prone. Local factors prevailed over regional factors in determining the number of N. baccharidis galls on 5. dracunculifolia, affecting the size of individual plants and suitability to the gall maker, without modifying the relationship between gall load and plant dimensions.

scholarly journals Dry and moist dynamics shape regional patterns of extreme precipitation sensitivity

2020 ◽  
Vol 117 (16) ◽  
pp. 8757-8763 ◽  
Author(s):  
Ji Nie ◽  
Panxi Dai ◽  
Adam H. Sobel
Keyword(s):  
Global Warming ◽  
Extreme Precipitation ◽  
Large Scale ◽  
Climate Model ◽  
Regional Scale ◽  
Vertical Motion ◽  
Precipitable Water ◽  
Small Scale ◽  
Climate Projections ◽  
Regional Patterns

Responses of extreme precipitation to global warming are of great importance to society and ecosystems. Although observations and climate projections indicate a general intensification of extreme precipitation with warming on global scale, there are significant variations on the regional scale, mainly due to changes in the vertical motion associated with extreme precipitation. Here, we apply quasigeostrophic diagnostics on climate-model simulations to understand the changes in vertical motion, quantifying the roles of dry (large-scale adiabatic flow) and moist (small-scale convection) dynamics in shaping the regional patterns of extreme precipitation sensitivity (EPS). The dry component weakens in the subtropics but strengthens in the middle and high latitudes; the moist component accounts for the positive centers of EPS in the low latitudes and also contributes to the negative centers in the subtropics. A theoretical model depicts a nonlinear relationship between the diabatic heating feedback (α) and precipitable water, indicating high sensitivity of α (thus, EPS) over climatological moist regions. The model also captures the change of α due to competing effects of increases in precipitable water and dry static stability under global warming. Thus, the dry/moist decomposition provides a quantitive and intuitive explanation of the main regional features of EPS.

Childhood foraging as regional culture: some implications for conservation policy

1998 ◽  
Vol 25 (3) ◽  
pp. 198-207 ◽  
Author(s):  
RAYMOND CHIPENIUK
Keyword(s):  
Personal Responsibility ◽  
Regional Scale ◽  
Resource Planning ◽  
Conservation Policy ◽  
Planning Theory ◽  
Wild Plants ◽  
Regional Culture ◽  
Ecological Identity ◽  
Regional Patterns ◽  
Foraging Experience

Natural resource planning theory now accepts that laypersons may acquire scientifically correct knowledge of nature by informal means and that sense of place, or ecological identity, motivates citizens to assume personal responsibility for their own bioregion. Previous research has identified childhood foraging, that is, searching for and using wild plants and animals of distinguishable kinds, as one informal means by which citizens learn about local ecosystems, but ethnographic evidence suggests foraging may also contribute substantially to the development of ecological identity. Does foraging reflect the ecological characteristics of local bioregions closely enough to structure ecological identity in industrial populations too? By way of addressing this question, studies were conducted to test predictions about the foraging repertoires of people growing up in two separate, but related, bioregions of Canada, centred on Niagara and Ottawa respectively. The most important of these predictions were, first, that regional patterns of foraging experience would correspond to regional ecological patterns, and second, that foraging repertoires would evince within-region similarities and between-region differences. Results confirm that the childhood foraging experience of ordinary Canadian citizens responds to important ecological parameters at the regional scale and in so doing constitutes an aspect of place-specific culture. These findings have a bearing on conservation policy, particularly for multicultural societies.

scholarly journals Adding landscape genetics and individual traits to the ecosystem function paradigm reveals the importance of species functional breadth

2017 ◽  
Vol 114 (48) ◽  
pp. 12761-12766 ◽  
Author(s):  
Antonio R. Castilla ◽  
Nathaniel S. Pope ◽  
Megan O’Connell ◽  
María F. Rodriguez ◽  
Laurel Treviño ◽  
...  
Keyword(s):  
Gene Flow ◽  
Seed Production ◽  
Critical Role ◽  
Pollen Dispersal ◽  
Plant Size ◽  
Dispersal Ability ◽  
Floral Display ◽  
Long Distance ◽  
Pollinator Community ◽  
Local Plant

Animal pollination mediates both reproduction and gene flow for the majority of plant species across the globe. However, past functional studies have focused largely on seed production; although useful, this focus on seed set does not provide information regarding species-specific contributions to pollen-mediated gene flow. Here we quantify pollen dispersal for individual pollinator species across more than 690 ha of tropical forest. Specifically, we examine visitation, seed production, and pollen-dispersal ability for the entire pollinator community of a common tropical tree using a series of individual-based pollinator-exclusion experiments followed by molecular-based fractional paternity analyses. We investigate the effects of pollinator body size, plant size (as a proxy of floral display), local plant density, and local plant kinship on seed production and pollen-dispersal distance. Our results show that while large-bodied pollinators set more seeds per visit, small-bodied bees visited flowers more frequently and were responsible for more than 49% of all long-distance (beyond 1 km) pollen-dispersal events. Thus, despite their size, small-bodied bees play a critical role in facilitating long-distance pollen-mediated gene flow. We also found that both plant size and local plant kinship negatively impact pollen dispersal and seed production. By incorporating genetic and trait-based data into the quantification of pollination services, we highlight the diversity in ecological function mediated by pollinators, the influential role that plant and population attributes play in driving service provision, and the unexpected importance of small-bodied pollinators in the recruitment of plant genetic diversity.

Factors determining the peak abundance of Metopolophium dirhodum (Homoptera: Aphididae) on cereals

1991 ◽  
Vol 81 (1) ◽  
pp. 57-64 ◽  
Author(s):  
A. Honěk
Keyword(s):  
Population Growth ◽  
Host Plant ◽  
Growth Rates ◽  
Plant Size ◽  
Leaf Nitrogen ◽  
Leaf Nitrogen Content ◽  
Metopolophium Dirhodum ◽  
Population Growth Rates ◽  
Maximum Abundance ◽  
Peak Abundance

AbstractFrom 1986 to 1989, the factors that determined the abundance of Metopolophium dirhodum (Walker) on cereals were studied in western Czechoslovakia. Forty seven sites were selected within cereal fields, mainly of winter wheat. Host plant size and leaf area varied between sites. The maximum abundance of M. dirhodum per tiller varied annually and with host plant stature. The main factor determining maximum abundance was the length of time for which the aphid population grew. M. dirhodum populations differed both in the time of the onset and termination of their growth. On stunted plants population growth started, with little variation, 200 day degrees later than on well developed plants. Within years, nearly all populations ceased growing simultaneously. In years of low or medium aphid abundance it was 40 to 90 day degrees earlier than in aphid outbreak years, and this extension of the population growth was the principal cause of the outbreak. Population growth rates varied slightly with plant quality and differed little between years. They were not important factors determining maximum abundances. 55–75% of the aphids occupied the flag leaves. The lower leaves of well developed plants were more heavily populated than nutritionally and water stressed smaller plants. The population growth rates on particular leaves were related to leaf nitrogen content, but not water content. A relationship for calculating the maximum abundances from a census made during the middle phase of population growth was proposed.

scholarly journals Late Miocene Vegetational History of Jackson Hole, Wyoming

1980 ◽  
Vol 4 ◽  
pp. 28-31
Author(s):  
C. Barnosky
Keyword(s):  
Plant Communities ◽  
Regional Scale ◽  
Pollen Record ◽  
Regional Patterns ◽  
Sufficient Detail ◽  
Dominant Feature ◽  
Community Evolution ◽  
Jackson Hole ◽  
History Of ◽  
Fossil Floras

The frequent reassortment of angiosperms to form new communities, a dominant feature of the Quaternary record, has seldom been recognized in earlier periods. In fact, analysis of fossil floras in North America suggests that Tertiary plant communities were relatively stable over long periods of time (for example, Hickey, 1977; MacGinitie, 1969; Wolfe, 1975). This stability suggests that either the record has not been studied in sufficient detail or that the factors controlling plant and environment interactions were less variable than in the Quaternary. If the latter hypothesis is true, the botanical record of the last 1.8x 10^6 yr may be an atypical model on which to base our understanding of community evolution . To assess the importance of short-term variation in Tertiary plant communities, detailed botanical analyses of continuous stratigraphic sections are needed. In particular, a pollen record through a lacustrine sequence is critical for recognizing rapid, floristic or vegetational changes on a regional scale. Thus far, such recognition has been difficult because our understanding of floristic development is based primarily on plant megafossils. While such material provides information on the riparian flora adjacent to a depositional site, it reveals little about regional patterns.

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