Canopy assemblages of ants in a New Guinea rain forest

2010 ◽  
Vol 27 (1) ◽  
pp. 83-91 ◽  
Author(s):  
Milan Janda ◽  
Martina Konečná
Keyword(s):  
Species Richness ◽  
Tree Species ◽  
New Guinea ◽  
The Other ◽  
Food Sources ◽  
Negative Effects ◽  
Lowland Forest ◽  
Ant Assemblages ◽  
Canopy Access ◽  
Plant Exudates

Abstract:The ant assemblages in two common tree species in primary lowland forest of New Guinea were explored using direct canopy access and tuna bait traps. The 19 trees investigated were occupied by 21 ant species of which 18 were canopy inhabitants. On average only 3.6 ant species per tree and 3 species per bait were found. Height of bait position was positively related to ant species richness, with the upper parts of the canopy being occupied by the highest number of species. On the other hand, tree species and study site did not have any effect on ant species richness nor on structure of the ant assemblages. Ant species appeared to be distributed randomly and we did not detect any effect of distance on similarity of ant assemblage occurring on the trees. The dominant species (Crematogaster polita) had certain negative effects on the presence of some species at food sources co-occurring at the same tree, but it did co-occur with the other ants to some extent as well. The majority of species found in the canopy were generalist omnivores (depending mainly on trophobionts or plant exudates).

Disturbance Impacts of Logging on Ground Herbaceous Plant Species Richness, Diversity, and Composition of Lowland Rainforest of Papua New Guinea

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Penniel Lamei ◽  
Fabio Attorre ◽  
Riccardo Testolin ◽  
Michele De Sanctis ◽  
Ruth Turia ◽  
...  
Keyword(s):  
Species Richness ◽  
Papua New Guinea ◽  
Forest Type ◽  
Elevation Gradient ◽  
New Guinea ◽  
Herbaceous Plant ◽  
Herbaceous Layer ◽  
Lowland Forest ◽  
P Type ◽  
The Impact

The impact of logging activities on species richness, diversity, and composition of the ground herbaceous layer of the lowland forest of Papua New Guinea was analyzed. Data from the first multipurpose National Forest Inventory were collected in 52 plots from logged and unlogged low altitude forest on plains and fans (P) and forest on uplands (H) in Madang, West New Britain and Central Provinces. The abundance of 10,609 ground herbaceous plants classified in 174 species from 103 genera and 35 families. Based on importance values, Arecaceae was the dominating family in both logged and unlogged P forest type, while Urticaceae and Arecaceae were dominating respectively in logged and unlogged H forest type. At species level, Donax canniformis and Elatostema beccarii are dominating the P type, and Elatostema novoguineensis and Selaginella durvillei the H type. Analysis of species richness, diversity, and composition showed significant differences between the two types with the H type being richer and more diverse than P type. No differences emerged between logged and unlogged of both types, indicating that the current intensity of disturbance does not seem to have a significant impact on the ground herbaceous layer. Since herbaceous species are an important component of the tropical forest diversity, further inventories must be conducted along a wider elevation gradient to make these results more robust and better observe species turn over patterns and beta diversity.

Development and regional planning within the decentralized administrative frame: case study (the Jordanian Experiment)

2018 ◽  
Vol 1 (2) ◽  
pp. 60-72
Author(s):  
Mansour Safran
Keyword(s):  
Regional Planning ◽  
The Other ◽  
Negative Effects ◽  
Administrative Procedures ◽  
The Way

This aims to review and analyze the Jordanian experiment in the developmental regional planning field within the decentralized managerial methods, which is considered one of the primary basic provisions for applying and success of this kind of planning. The study shoed that Jordan has passed important steps in the way for implanting the decentralized administration, but these steps are still not enough to established the effective and active regional planning. The study reveled that there are many problems facing the decentralized regional planning in Jordan, despite of the clear goals that this planning is trying to achieve. These problems have resulted from the existing relationship between the decentralized administration process’ dimensions from one side, and between its levels which ranged from weak to medium decentralization from the other side, In spite of the official trends aiming at applying more of the decentralized administrative policies, still high portion of these procedures are theoretical, did not yet find a way to reality. Because any progress or success at the level of applying the decentralized administrative policies doubtless means greater effectiveness and influence on the development regional planning in life of the residents in the kingdom’s different regions. So, it is important to go a head in applying more steps and decentralized administrative procedures, gradually and continuously to guarantee the control over any negative effects that might result from Appling this kind of systems.   © 2018 JASET, International Scholars and Researchers Association

The mechanisms explaining tree species richness and composition are convergent in a megadiverse hotspot

2019 ◽  
Vol 29 (3) ◽  
pp. 799-815
Author(s):  
Victor P. Zwiener ◽  
André A. Padial ◽  
Márcia C. M. Marques
Keyword(s):  
Species Richness ◽  
Tree Species ◽  
Tree Species Richness

scholarly journals Effect of tree species identity and related habitat parameters on understorey bryophytes – interrelationships between bryophyte, soil and tree factors in a 50-year-old experimental forest

2021 ◽  
Author(s):  
Kaja Rola ◽  
Vítězslav Plášek ◽  
Katarzyna Rożek ◽  
Szymon Zubek
Keyword(s):  
Species Richness ◽  
Tree Species ◽  
Forest Floor ◽  
Vascular Plant ◽  
Soil Parameters ◽  
Species Identity ◽  
Habitat Factors ◽  
Positive Correlations ◽  
Old Trees ◽  
Habitat Parameters

Abstract Aim Overstorey tree species influence both soil properties and microclimate conditions in the forest floor, which in turn can induce changes in ground bryophyte communities. The aim of the study was to investigate the effect of tree species identity and the most important habitat factors influencing understorey bryophytes. Methods We assessed the effect of 14 tree species and related habitat parameters, including soil parameters, vascular plant presence and light intensity on bryophytes in monospecific plots covered by nearly fifty-year-old trees in the Siemianice Experimental Forest (Poland). Results The canopy tree species determined bryophyte species richness and cover. The strongest differences were observed between plots with deciduous and coniferous trees. Soils with a more acidic pH and lower content of macronutrients supported larger bryophyte coverage. We also found a positive correlations between vascular plants and availability of light as well as bryophyte species richness. Conclusion Tree species identity and differences in habitat conditions in the forest floor lead to changes of ground bryophyte richness, cover and species composition. Consequently, the changes in the dominant tree species in the stand may result in significant repercussions on ground bryophyte communities. We indicated that the introduction of alien tree species, i.e. Quercus rubra, has an adverse effect on bryophyte communities and suggested that the selection of tree species that contribute to the community consistent with the potential natural vegetation is highly beneficial for maintaining ground bryophyte biodiversity.

scholarly journals Facilitation Effects of Haloxylon salicornicum Shrubs on Associated Understory Annuals, and a Modified “Stress-Gradient” Hypothesis for Droughty Times

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1726
Author(s):  
Nasr H. Gomaa ◽  
Ahmad K. Hegazy ◽  
Arafat Abdel Hamed Abdel Latef
Keyword(s):  
Species Richness ◽  
Water Availability ◽  
Stress Gradient ◽  
Growing Season ◽  
Annual Species ◽  
Negative Effects ◽  
Growing Seasons ◽  
Dry Seasons ◽  
The Impact ◽  
Haloxylon Salicornicum

Perennial shrub-annual plant interactions play key roles in desert regions influencing the structure and dynamics of plant communities there. In the present study, carried out in northwestern Saudi Arabia, we examined the effect of Haloxylon salicornicum shrubs on their associated understory annual species across four consecutive growing seasons, along with a record of the seasonal rainfall patterns. We measured density and species richness of all the annual species in permanent quadrats located beneath individual shrubs, as well as in the spaces between shrubs. During wet growing season H. salicornicum shrubs significantly enhanced the density and species richness of sub-canopy species, whereas in the relatively dry seasons they exerted negative effects on the associated species. In all growing seasons, the presence of shrubs was associated with enhanced soil properties, including increased organic carbon content, silt + clay, and levels of nutrients (N, P and K). Shrubs improved soil moisture content beneath their canopies in the wet growing season, while in the dry seasons they had negative effects on water availability. Differences in effects of H. salicornicum on understory plants between growing seasons seem due to the temporal changes in the impact of shrubs on water availability. Our results suggest the facilitative effects of shrubs on sub-canopy annuals in arid ecosystems may switch to negative effects with increasing drought stress. We discuss the study in light of recent refinements of the well-known “stress-gradient hypothesis”.

scholarly journals Salinity and freshwater discharge determine rotifer distribution at the Mossoró River Estuary (Semiarid Region of Brazil)

2010 ◽  
Vol 70 (3) ◽  
pp. 551-557 ◽  
Author(s):  
AMA. Medeiros ◽  
JEL. Barbosa ◽  
PR. Medeiros ◽  
RM. Rocha ◽  
LF. Silva
Keyword(s):  
Species Richness ◽  
Rainy Season ◽  
Salinity Gradient ◽  
River Estuary ◽  
Positive Influence ◽  
Freshwater Discharge ◽  
The Other ◽  
Semiarid Region ◽  
Inverse Estuary ◽  
Species Richness And Abundance

The present study aimed at evaluating differences in rotifer distribution in three estuarine zones in an inverse estuary located in the Semiarid Region of Brazil. Zones were chosen based on their proximity to the ocean and river border as a means of reflecting a horizontal salinity gradient. High freshwater discharge during the rainy season was the major determinant of rotifer composition. On the other hand, due to higher salinity values during the dry season, very low values of species richness and abundance were observed in all zones. Therefore, the study highlights the constraints of salinity and the positive influence of seasonality and river proximity on rotifer species in a semiarid estuarine environment.

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