scholarly journals Tropical Terrestrial And Epiphytic Ferns Have Different Leaf Stoichiometry With Ecological Implications.

2021 ◽  
Author(s):  
Syazwan Pengiran Sulaiman ◽  
Daniele Cicuzza
Keyword(s):  
N:P Ratio ◽  
Forest Species ◽  
Tropical Regions ◽  
Brunei Darussalam ◽  
Ecological Implications ◽  
Fern Species ◽  
Leaf Stoichiometry ◽  
Stochastic Events ◽  
Species Being ◽  
Epiphyte Species

Abstract Terrestrial and epiphytic herbaceous forest species have different ecology and leaf stoichiometry. In tropical regions, a great component of herbaceous forest species is represented by ferns with different lifeforms. However, little is known about the differences in leaf stoichiometry between the lifeforms. We account for the concentrations of leaf elements (N, P, K, Ca and Mg) between terrestrial and epiphyte lifeforms and evolutionary clades. The fern species were sampled from the forest of Brunei Darussalam. Five leaves were collected from 5 individuals from 16 terrestrial and 4 epiphytic ferns. The leaves were then acid-digested and analyzed. Epiphytic species had higher concentration of most of the leaf elements. The N:P ratio showed that the epiphytic species being much more nutrient-limited, relying on stochastic events, compared to the terrestrial species which have a constant availability of soil elements. Epiphytes showed a higher concentration of P, which could be explained by their luxury consumption. Epiphytes accumulate elements in a higher concentration than is needed by their normal metabolic activity. Furthermore, epiphyte species have a significantly higher concentration of Ca which could be interpreted as necessity of coping with severe habitat conditions with schlerophyll leaves. The results bring in more information on the poorly studied stoichiometry of tropical Asian fern species. Important in understanding the eco-physiology of terrestrial and epiphytic ferns and determining which species are sensitive to the different forest management and the effect of climate change. This, is in addition to the associated mechanisms.

scholarly journals Landscape structure and climate seasonality affect the amount, richness and diversity of pollen collected by honeybees in a Neotropical region of Colombia

2020 ◽  
Author(s):  
Paula María Montoya-Pfeiffer ◽  
Guiomar Nates-Parra
Keyword(s):  
Landscape Structure ◽  
Urban Areas ◽  
Native Species ◽  
Diversity Index ◽  
Forest Area ◽  
Colony Development ◽  
Monthly Precipitation ◽  
Forest Species ◽  
Tropical Regions ◽  
Pollen Species

AbstractPollen is the main food for honeybee broods and young workers and so colony development and reproduction rely heavily on pollen availability, both spatially and temporally, in the environment. Intensification of agriculture and climate seasonality are known to alter honeybee foraging patterns and pollen intake through changes in resource availability in temperate regions; however, little is known about how honeybees respond to such environmental factors in tropical regions.Pollen species collected by honeybees in a Neotropical agricultural region of Colombia were identified. The effects of landscape structure (landscape Shannon Diversity Index, forest area in 1000 m around the apiary) and climate seasonality (mean monthly precipitation) on the amount, richness and diversity of pollen collected by the honeybees were evaluated for all pollen species together and pollen species segregated according to forest and anthropic areas (croplands, grasslands, woodlands, urban areas).Honeybees were found to be much more associated with anthropic than forest pollen species regardless of landscape structure or precipitation. However, the amount, richness and diversity of pollen from all species and forest species responded positively to landscape diversity and forest area, suggesting an advantage for honeybees in obtaining small quantities of pollen from forest species, in spite of being well-adapted to forage in anthropic areas. Precipitation was found not to be related to the overall amount and overall richness of pollen collected by honeybees, suggesting that climate seasonality was not an important factor for pollen foraging. Nonetheless, overall pollen diversity was negatively affected by precipitation in less diverse landscapes, while anthropic pollen diversity was negatively affected in more forested landscapes. These findings are compared with those from temperate regions, and the implications for honeybee productivity and survival, and their interactions with Neotropical native species, are discussed.

scholarly journals Habitat exploitation by landbirds in the changing Western Samoan environment

1992 ◽  
Vol 2 (2) ◽  
pp. 123-129 ◽  
Author(s):  
S. M. Evans ◽  
F. J. C. Fletcher ◽  
P. J. Loader ◽  
F. G. Rooksby
Keyword(s):  
Urban Life ◽  
Indigenous Species ◽  
Forest Species ◽  
Urban Habitats ◽  
Severe Loss ◽  
Western Samoa ◽  
Native Birds ◽  
Species Being ◽  
Increased Pressure

SummaryThe avifauna of Western Samoa is dominated by indigenous species, including several endemic ones. They are primarily birds of the rainforest and, since the islands have already suffered severe loss of this habitat and there is likely to be increased pressure on it in the future, their long-term prospects are not good. At present, introduced, non-native birds are not a threat to indigenous species, being confined largely to urban habitats, and there is little interaction with forest species. Several indigenous species exploit manmodified habitats, however, and it is possible that, as has occurred elsewhere, some of them may adapt fully to urban life.

scholarly journals Argasid Ticks of Palearctic Bats: Distribution, Host Selection, and Zoonotic Importance

2021 ◽  
Vol 8 ◽  
Author(s):  
Attila D. Sándor ◽  
Andrei Daniel Mihalca ◽  
Cristian Domşa ◽  
Áron Péter ◽  
Sándor Hornok
Keyword(s):  
Host Selection ◽  
Tick Species ◽  
Point Of View ◽  
Host Specialization ◽  
Soft Tick ◽  
Tropical Regions ◽  
Terrestrial Vertebrates ◽  
Western Palearctic ◽  
Wide Geographic Distribution ◽  
Species Being

The soft ticks (Ixodida: Argasidae) are ectoparasites of terrestrial vertebrates with a wide geographic distribution, occurring on all continents. These ticks are obligate blood-feeders, most of them show high degrees of host-specialization and several species in arid and tropical regions are important parasites of livestock and men. Species commonly occurring on domestic animals and man are generally well-known, with many studies focusing on their ecology, distribution or vectorial role. However, wildlife-specialist soft ticks are less studied. Nearly half of all soft tick species are bat specialists, with five species (Carios vespertilionis, Chiropterargas boueti, Chiropterargas confusus, Reticulinasus salahi, and Secretargas transgariepinus) occurring in the Western Palearctic. There is no comprehensive study on the distribution, hosts or pathogens in these soft ticks, although most species were shown to carry several viral, bacterial, or protozoan pathogens and also to occasionally infest humans. Based on a literature survey and 1,120 distinct georeferenced records, we present here the geographical range, host selection and vectorial potential for bat-specialist soft ticks occurring in the Western Palearctic (chiefly Europe, North Africa, and the Middle East). Carios vespertilionis shows the largest distribution range and was found on most host species, being ubiquitous wherever crevice-roosting bats occur. All the other species were located only in areas with Mediterranean climate, with Ch. boueti, Chiropteraragas confusus, and R. salahi are missing entirely from Europe. These three species have a host spectrum of bats roosting primarily in caves, while S. transgariepinus and Ca. vespertilionis is feeding primarily on crevice-roosting bat species. All but one of these soft tick species are known to feed on humans and may be vectors of important disease agents (Rickettsia spp., Borrelia spp., Bartonella spp., Ehrlichia spp., Babesia spp., several nairo-, and flaviviruses). As several crevice-roosting bat species show a continuous adaptation to human-altered areas, with certain species becoming common city-dwellers in the Western Palearctic, the study of bat specialist soft ticks is also important from an epidemiologic point of view.

The life of a Hepatozoon (Sporozoa: Adeleidea) of varanid Lizards in Australia.

1962 ◽  
Vol 10 (1) ◽  
pp. 35 ◽  
Author(s):  
MJ Mackerras
Keyword(s):  
Small Mammals ◽  
Sugar Cane ◽  
Rain Forest ◽  
Large Carnivores ◽  
Forest Species ◽  
Mammal Species ◽  
Open Forest ◽  
Set Up ◽  
Species Being ◽  
Diurnal Species

Innisfail, a small coastal town in north Queensland, lies on the plain between the Atherton Plateau and the coastal hills, an area once covered with tropical rain-forest, but now extensively cleared for the growing of sugar cane. As part of an investigation of leptospirosis, small mammals have been collected, and mark-recapture experiments set up in areas sampling vegetation of different kinds. The species found comprised two monotremes, ten marsupials, nine bats (which were not collected intensively), nine rodents, and three other mammals. Some difficulty was experienced in distinguishing the local rodents, and a key to the species is given. This fauna could be divided into three elements: a rain-forest fauna of 14 species (excluding bats), a sugar-cane fauna of ten species, and a house fauna of four species. The sugar-cane fauna is shown to be derived, not from the rain-forest species, but from part of the fauna of the open forest which covers the hinterland, all the species being also recorded from New Guinea. The rain-forest fauna agrees with the list of species recorded from this part of Australia. A comparison is made with Malayan rain-forest, which is richer in mammal species. The niches corresponding to those of the nocturnal Malayan mammals seem well filled, but there is a deficiency of mammals corresponding to the diurnal species, such as monkeys, squirrels, and cattle, and also to the large carnivores.

scholarly journals Biogeography and conservation of the herpetofauna of the Upland Pine-Oak Forests of Honduras

2007 ◽  
Vol 7 (1) ◽  
pp. 131-142 ◽  
Author(s):  
Larry David Wilson ◽  
Josiah Harold Townsend
Keyword(s):  
Oak Forests ◽  
Oak Forest ◽  
Population Status ◽  
Forest Species ◽  
Habitat Types ◽  
Environmental Threat ◽  
Anthropogenic Habitat ◽  
Isthmus Of Tehuantepec ◽  
Species Being ◽  
Stable Populations

The upland pine-oak forest herpetofauna constitutes the smallest segment distributed in the major habitat types in Honduras, due to its occurrence at moderate elevations in relatively inhospitable environments, compared to more mesic habitats in the country. This segment, however, is subject to considerable environmental threat as a consequence of annual burning and logging. Of the 356 herpetofaunal species known from Honduras, 105 are known from these habitats. These forests occur throughout much of the mountainous interior of Honduras. They are subject to the Intermediate Dry climate. Four salamanders, 27 anurans, four turtles, 29 lizards, and 41 snakes comprise the herpetofauna. These species are partitioned into restricted, widespread, and peripheral distributional categories. They can be allocated to eleven broad distributional categories, with most belonging to the category containing species whose ranges extend from somewhere in Mexico north of the Isthmus of Tehuantepec to somewhere in South America. The large majority are terrestrial forest inhabitants, arboreal forest inhabitants, terrestrial pondside species, or terrestrial forest pondside species. Most species are judged common, with the next largest group considered to be of infrequent occurrence, and the smallest group of rare occurrence. Upland pine-oak forest species are distributed among four ecophysiographic areas, with the greatest number of species being found in the Southeastern Uplands. Construction of a CBR diagram illustrates that the herpetofaunas of the Northwestern and Northeastern Uplands, the Northeastern Uplands and Southeastern Uplands, and the Southeastern Uplands and Southwestern Uplands are about equally related to one another. The greatest significance of the upland pine-oak forest herpetofauna lies in the relatively high percentage of members presently possessing stable populations, indicating their apparent greater ability to resist anthropogenic habitat disturbance. Few species currently have populations in decline, but about a third lack sufficient data to characterize their population status, indicating the need for considerable additional fieldwork before their conservation issues can be properly addressed.

The resorption of phosphorus is greater than that of nitrogen in senescing leaves of vascular epiphytes from lowland Panama

2004 ◽  
Vol 20 (6) ◽  
pp. 693-696 ◽  
Author(s):  
Gerhard Zotz
Keyword(s):  
Plant Growth ◽  
Tropical Forests ◽  
N:P Ratio ◽  
Nutrient Ratios ◽  
Vascular Epiphytes ◽  
Mature Leaves ◽  
P Limitation ◽  
N:P Ratios ◽  
Epiphyte Species ◽  
Nutrient Relations

The epiphytic habitat is assumed to be nutrient deficient, although this generally held notion is based almost completely on circumstantial evidence (Zotz & Hietz 2001). Most studies on the nutrient relations of vascular epiphytes focus on nitrogen (Bergstrom & Tweedie 1998, Hietz & Wanek 2003, Stewart et al. 1995). Although nitrogen plays a key role in limiting plant growth worldwide, there is an on-going discussion whether nitrogen or rather phosphorus are more limiting in many tropical forests (Grubb 1989, Harrington et al. 2001, Vitousek & Howarth 1991). To identify which nutritional factor is most limiting for plant growth, nutrient ratios have been proposed as a very useful tool (Koerselman & Meuleman 1996). These authors stated that N:P ratios exceeding 16 are indicative of P limitation, while an N:P ratio <14 suggests N limitation. Some reports of such ratios in the epiphyte literature indicate that phosphorus may indeed be limiting for epiphytes in tropical forests. For example, the N:P ratio of two field-grown bromeliads (Tillandsia circinnata and T. usneoides) decreased dramatically from 23.6 and 40.4, respectively, to 3.6 and 3.4, respectively, when fertilized with both N and P in the laboratory (Benzing & Renfrow 1974a). On the other hand, however, the average N:P ratios of mature leaves of 41 epiphyte species compiled from a number of papers did not appear particularly high (12.1±10.5, cf. Zotz & Hietz 2001).

scholarly journals Effects of nitrogen and phosphorus availability on the early growth of two congeneric pairs of savanna and forest species

2022 ◽  
Vol 82 ◽  
Author(s):  
B. Paganeli ◽  
M. A. Batalha
Keyword(s):  
Leaf Area ◽  
Phosphorus Limitation ◽  
Tropical Region ◽  
Total Biomass ◽  
Forest Species ◽  
Nitrogen And Phosphorus ◽  
Tropical Regions ◽  
Hoagland Solution ◽  
Nutritional Strategies ◽  
Seasonal Forests

Abstract In the tropical region, savannas and seasonal forests, both highly diverse biomes, occur side by side, under the same climate. If so, that mosaic cannot be explained solely by climatic variables, but also by fire, water availability and soil status. Nutrient availability in the soil, especially nitrogen and phosphorus, has been postulated to explain the abrupt transitions between savannas and seasonal forests in tropical regions. Plants from these two biomes may present different nutritional strategies to cope with nitrogen and phosphorus limitation. We used two congeneric pairs of trees — each pair with a species from the savanna and another from the neighboring seasonal forest — to test whether savanna and forest species presented different nutritional strategies during their early development. We cultivated 56 individuals from each of these species in a hydroponics system with four treatments: (1) complete Hoagland solution, (2) Hoagland solution without nitrogen, (3) Hoagland solution without phosphorus, and (4) Hoagland solution without nitrogen and phosphorus. After 45 days, we harvested the plants and measured total biomass, root to shoot ratio, height, leaf area, and specific leaf area. Overall, savanna species were lighter, shorter, with smaller leaves, higher specific leaf areas, and higher root to shoot ratios when compared to the forest species. Nitrogen increased the performance of species from both biomes. Phosphorus improved the performance of the forest species and caused toxicity symptoms in the savanna species. Hence, savanna and forest species presented different demands and were partially distinct already as seedlings concerning their nutritional strategies.

scholarly journals The impact of tropical land-use change on downstream riverine and estuarine water properties and biogeochemical cycles: a review

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Yasuaki Tanaka ◽  
Elizerberth Minggat ◽  
Wardina Roseli
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Land Use Changes ◽  
N:P Ratio ◽  
Biogeochemical Cycles ◽  
Estuarine Water ◽  
Warm Temperature ◽  
Tropical Regions ◽  
The Impact ◽  
Primary Forests

AbstractTropical primary forests have been disappearing quickly to make use of the land for commercial purposes. Land-use change has an impact on downstream aquatic processes, but those impacts have mainly been studied in temperate climate regions. The present article reviews the impacts of various tropical land-use changes caused by human activities on downstream riverine and estuarine water properties and biogeochemical cycles, focusing especially on the behaviors of nitrogen (N) and phosphorus (P). Logging of tropical primary forests, subsequent establishment of pasture lands, and occasional wildfire or intentional burning have decreased terrestrial N fixation and increased the discharge of P combined with soils, which has lowered the N:P ratio of dissolved inorganic nutrients in the adjacent stream waters and downstream rivers. Agricultural fertilizers and aquacultural practices basically cause nutrient enrichment in downstream riverine and estuarine waters, changing the N:P ratio depending on the source. Finally, urbanization causes eutrophication in many tropical estuaries, where a halocline forms easily because of a warm temperature throughout the year and the water at the bottom of the estuary tends to become hypoxic or anoxic. Overall, the impact of land-use change on aquatic processes may be more serious in tropical regions than in temperate or cold climate regions because of (1) a higher biomass and nutrient stock in original tropical forests; (2) higher precipitation, more frequent episodic flooding, and warmer temperatures in tropical regions; and (3) certain practices that are rapidly expanding in tropical regions such as land-based aquaculture. Various land-use changes are causing downstream nutrient enrichment or disturbance of the nutrient balance at tropical land-sea interfaces, and the overall N:P ratios in the aquatic ecosystem seem to be declining. Nonetheless, if proper management is conducted and the discharge of nutrients and soils ceases, tropical aquatic systems may have the potential to recover faster than those in other climate regions because of their abundant precipitation and warm temperature. Long-term monitoring and more attention to elemental stoichiometry are important areas for future research.

Tracing migration of larger benthic foraminifera across atolls in the South China Sea

2021 ◽  
Author(s):  
Sulia Goeting ◽  
Antonino Briguglio ◽  
Laszlo Kocsis ◽  
Amajida Roslim
Keyword(s):  
South China Sea ◽  
South China ◽  
Benthic Foraminifera ◽  
Biodiversity Hotspot ◽  
Migration Pattern ◽  
Shallow Waters ◽  
Larger Benthic Foraminifera ◽  
Tropical Regions ◽  
China Sea ◽  
Brunei Darussalam

&lt;p&gt;The distribution of modern benthic foraminifera is studied from offshore reefs of Brunei Darussalam located in northwest Borneo with enhanced siliclastic influence, and from Louisa Reef, an atoll in the Southern Spratly Islands under fully carbonatic environment. The main families of larger benthic foraminifera found from offshore reefs of Brunei are the Calcarinidae, Amphisteginidae and the Operculinidae, while at the Louisa Reef are the Calcarinidae, Amphisteginidae and the Soritidae. Larger benthic foraminifera are mainly concentrated in the tropical regions and in shallow waters, and their distribution depends on important environmental factors such as water depth, sunlight and type of sediment. Migration of LBF has been recorded since the Paleogene from the Americas to Africa and the Mediterranean Sea, and later to the Indo-Pacific where the modern biodiversity hotspot occurs. Hence looking into any possible migration throughout certain groups of LBF could help in understanding their biogeographic distribution through time within the Indo-Pacific region. Along the atolls in South China Sea the marine environments meet their living preferences, hence tracing their presence, distributions, and abundances could shed further light on their regional migration pattern.&lt;/p&gt;

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