Disproportionately large ecological role of a recently mass-culled flying fox in native forests of an oceanic island

Variation in woody vegetation among sites with different disturbance histories in the Argentine Chaco

Herbivores can profoundly influence plant species assembly, including plant invasion, and resulting community composition. Population increases of native herbivores, e.g. white-tailed deer (Odocoileus virginianus), combined with burgeoning plant invasions raise concerns for native plant diversity and forest regeneration. While individual researchers typically test for the impact of deer on plant invasion at a few sites, the overarching influence of deer on plant invasion across regional scales is unclear. We tested the effects of deer on the abundance and diversity of introduced and native herbaceous and woody plants across 23 white-tailed deer research sites distributed across the east-central and north-eastern USA and representing a wide range of deer densities and invasive plant abundance and identity. Deer access/exclusion or deer population density did not affect introduced plant richness or community-level abundance. Native and total plant species richness, abundance (cover and stem density) and Shannon diversity were lower in deer-access vs. deer-exclusion plots. Among deer-access plots, native species richness, native and total cover, and Shannon diversity (cover) declined as deer density increased. Deer access increased the proportion of introduced species cover (but not of species richness or stem density). As deer density increased, the proportion of introduced species richness, cover and stem density all increased. Because absolute abundance of introduced plants was unaffected by deer, the increase in proportion of introduced plant abundance is likely an indirect effect of deer reducing native cover. Indicator species analysis revealed that deer access favoured three introduced plant species, including Alliaria petiolata and Microstegium vimineum, as well as four native plant species. In contrast, deer exclusion favoured three introduced plant species, including Lonicera japonica and Rosa multiflora, and 15 native plant species. Overall, native deer reduced community diversity, lowering native plant richness and abundance, and benefited certain invasive plants, suggesting pervasive impacts of this keystone herbivore on plant community composition and ecosystem services in native forests across broad swathes of the eastern USA.

This paper has reviewed on the extent of various studies conducted to describe the diversity of fruit bats (Family Pteropodidae), its conservation and management in the tropical forests of Southeast Asian Region. The study was anchored on synthesizing published articles from February to May 2022 through data banking using keywords: bats, fruit bats, fruit bat diversity, conservation management, tropical forests with regards to the respective country. Results showed that diversity of fruit bats (Family Pteropodidae) inhabiting the tropical forest of Southeast Asia has a total of 99 fruit bat species with a total of 19 conservation initiatives undertaken. These included population conservation, protection and management of their food sources and habitats. Generally, majority of the studies all throughout Southeast Asia revealed the presence of adversely affected bat communities after forest disturbance and destruction. The study recommend further research in some countries of Southeast Asia, some specific study on fruit bats should include ectoparasitism, vectors of infectious diseases like rabies and other viruses, and other studies, some studies should be conducted as well for other bat families like insectivorous and nectarivorous bats, strict implementation of laws and legislations focused on protecting fruit bats, their food sources and habitats, and the entire forest ecosystem, and in situ fruit bat initiatives like increasing the Information, Education and Communication (IEC) campaign such as no direct killing and commercialization.

Variation in vegetation structure and soil properties related to land use history of old-growth and secondary tropical dry forests in northwestern Mexico

Postharvest application of 1-methylcycloprepene (1-MCP) on banana fruit to extend shelf-life and maintain quality is inconsistent as treated fruit do not ripen uniformly. Banana response to 1-MCP treatment can be variable due to within-bunch variation in fruit size, composition, and maturity. Therefore, the present study investigated whether fruit size variation explains variability in ripening recovery. To investigate this relationship, large, medium, and small fruit were treated with 0 nL L−1 1-MCP (control), 400 nL L−1 1-MCP and 50 µL L−1 ethephon + 400 nL L−1 1-MCP. Fruit were then ripened using 800 µL L−1 ethephon and stored at 23 °C for 30 d. Irrespective of fruit size, treating banana with 1-MCP and ethephon + 1-MCP prolonged shelf-life by 30 d compared to control, which were fully ripe at 15 d for medium and large fruit, and 20 d for small fruit. 1-MCP significantly delayed yellow colour development (colour stage 4), chlorophyll degradation (97.4 µg/g), and sucrose (2.57 mg/g) and glucose (0.86 mg/g) accumulation in small compared to medium and large fruit. However, firmness (56.13 N) and starch (0.68 mg/g) were significantly lower in 1-MCP-treated small-sized fruit compared to medium and large fruit. Moisture loss was also significantly higher (19.49%) in 1-MCP-treated small fruit compared to medium (14.89%) and large (18.11%). Combined ethephon and 1-MCP allowed for an increase in ripening in small, medium, and large fruit. Overall, medium and large fruit treated with 1-MCP and ethephon + 1-MCP recovered their ripening capacity better compared to small fruit. The results demonstrate that 1-MCP efficacy is influenced by fruit size, whereas ethephon + 1-MCP treatment was consistent across small, medium, and large fruit. The effect of fruit size on 1-MCP efficacy might explain the inconsistency of the treatment in the banana fruit. Therefore, it is important to apply 1-MCP on fruit of approximately the same size to achieve the full benefit of the treatment. Moreover, fruit treated with 1-MCP + ethephon recovered their ripening capacity, irrespective of size, suggesting that it is a beneficial treatment.

Flying foxes play keystone ecological roles in plant reproduction. Yet, they face numerous threats, including persecution for eating commercial fruits. This human-wildlife conflict has recently escalated to culling campaigns of a threatened flying fox on Mauritius. Finding non-lethal solutions to this human-wildlife conflict on the island is therefore extremely important. We hypothesized that invasive alien plants may reduce native fruit availability through competition and that weeding alien plants could improve the native foraging habitat quality of flying foxes – in turn, reducing their consumption of commercially important fruits. We compared native fruit production and foraging intensity of the Mauritian flying fox (Pteropus niger) in forests weeded of alien plants a decade previously and adjacent non-weeded forests. Fruits and ejecta were collected weekly during five months under 144 randomly chosen native trees of two canopy species whose fruits are eaten by flying foxes. Intraspecific variations in tree and fruit traits were used to examine flying fox foraging preference. Native fruit production was significantly higher in weeded forests for both tree species, and this was matched by higher flying fox foraging intensity. Flying foxes preferred large trees and fed predominantly on large and ripe fruits. The predominant consumption of ripe fruits emphasizes the importance of flying foxes as seed dispersers. Our results indicate that alien plant invasion substantially reduces native fruit production and that weeded forests provide a much better habitat for flying foxes. Our findings lend support to invasive alien plant control as a management strategy in mitigating such human-wildlife conflicts.

The impact of logging on plant communities was studied in forest that has been logged selectively 1, 5 and 10 years previously (following a certified procedure): diversity was compared with that of primary rain forest in the Berau region of East Kalimantan, Indonesia. Four sets of 20 transects located within an area of 6 ha were sampled for all trees, saplings and seedlings, and records were made of topographic position, structure, composition and species diversity. There was a high level of floristic similarity between primary forests at the study sites compared to primary forest elsewhere in Kalimantan. The impact of logging is therefore likely to be the most important factor determining any differences between the plant communities of the selectively logged and primary forest sites. We found differences in species composition and abundance of most plants between selectively logged and primary forest. Overall, stem densities of trees in the primary forest were higher than in the three selectively logged forest sites. Stem densities of saplings were equivalent in all four forests. Seedling stem densities were higher in the forest site logged 10 years previously than in primary forest. Our results showed that the forests logged selectively under certified regimes still have a high plant diversity, possibly indicating that biodiversity values may be conserved by following certification procedures.

Vegetation response of a mesquite-mixed brush community to aeration

Abstract. Ransaleleh TA, Kawatu M, Wahyuni I, Onibala J, Nangoy MJ, Umboh S, Rembet UNWJ, Saputro S, Wiantoro S. 2024. Fruit bats trade in the traditional markets of South Minahasa, Sulawesi, Indonesia. Biodiversitas 25: 716-725. The hunting and trading of fruit bats are significant sources of income for several communities in North Sulawesi, Indonesia. Therefore, this research aimed to map the market locations and identify the species of traded bats, along with their conservation status in South Minahasa District. Surveys of markets, hunters, and sellers were conducted for 5 months from May to September 2023. Morphological examinations were carried out on the traded bats, focusing on several parameters such as body weight, morphometric and description of the morphological characters. We identified the traditional markets which sell fruit bats (family Pteropodidae), Acerodon celebensis and Pteropus alecto meat, namely Berdikari Tumpaan, 54 Amurang, 45 Langsot Tareran, Tenga, Pakuure, Ongkaw, Soko Raanan Baru, Motoling, Poigar, Poopo, Pinaesaan Tompaso Baru, and Pinasungkulan Modoinding. Furthermore, two markets, namely Pakuure and Pinaesaan Tompaso Baru, were identified selling the small fruit bats (family Pteropodidae), Cynopterus minutus, Dobsonia exoleta, Nyctimene cephalotes, Rousettus amplexicaudatus, and Thoopterus nigrescens. According to the International Union for Conservation of Nature (IUCN) Red List, A. celebensis and D. exoleta are endemic bat species in Sulawesi with a conservation status of vulnerable and least concern, respectively. Fostering education and advocacy program is crucial to promote awareness and conservation strategy, especially for the 12 traditional markets which trade seven fruit bat species in South Minahasa, Sulawesi.

Stand structure and temporal variability in old-growth beech-dominated forests of the northwestern Carpathians: A 40-years perspective

The aim of the research was to establish the features of the inheritance of the size of the fruit in the hybrid families of Prunus domestica. The objects of study were hybrid seedlings of plum selection of the Tatar research Institute of agriculture. Fruit sizes were estimated according to the methodology of the all-Russian research Institute of fruit crops selection. The analysis of the splitting of plum in hybrid families by the size of fruits showed that seedlings with small fruits dominated in the breeding gardens of the Tatar research Institute. The size of the plum fruit is controlled by polygens. All of the original parental forms are heterozygotes for the genes determining the size of the fruit. A small fruit is a dominant trait, a large fruit is a recessive trait. In most hybrid families, plum seedlings have a significant variability in the size of the fruit. Transgressive genotypes with large fruits are formed in hybrid families Eurasia 21 x Renklod Tenkovsky, Eurasia 21 x free pollination and Zyuzinskaya x free pollination. The varieties Eurasia 21 and Zyuzinskaya must be used as sources in breeding of plums for large-fruited.

In einer vergleichenden Studie wurde eine Chronosequenz verschiedener Sukzessionsstadien eines Bergregenwaldes der oberen montanen Stufe der Cordillera Talamanca, Costa Rica, untersucht. Diese umfaßte einen 10-15jährigen Sekundärwald, einen 40jährigen Sekundärwald und einen Altbestand (Primärwald). Ziel der Untersuchung war die Klärung der Fragen, (a) wie sich die Bestandesstruktur und die epiphytische Biomasse der Bestände im Sukzessionsverlauf verändern und (b) welche ökosystemare Bedeutung die Epiphyten für den Kronenwasserumsatz und die Nährstoffflüsse in den drei Waldstadien haben.Die bestandesstrukturellen Untersuchungen ergaben, daß sich die drei Waldstadien deutlich in Bestandeshöhe, Stammdichte, Anzahl der Baumschichten sowie dem Anteil von ober- und unterständigen Bäumen unterschieden. Der mit dem Blattflächenmeßgerät LAI 2000 ermittelte Blattflächenindex zeigte im jungen Sekundärwald und im Altbestand keine signifikanten Unterschiede, während im älteren Sekundärwald ein um 24% höherer Wert gemessen wurde. Die Bestimmung des LAI anhand des Blattstreufalls ergab bei einer Blattlebensdauer von 1.5 Jahren 8.8 m2 m-2 im jungen Sekundärwald, 13.8 m2 m-2 im älteren Sekundärwald und 7.7 m2 m-2 im Altbestand.Die Streuproduktion ließ deutliche Unterschiede zwischen den drei Waldstadien erkennen, wobei die im älteren Sekundärwald und im Altbestand ermittelten jährlichen Gesamtmengen der Feinstreu mit 1720 g m-2 a-1 bzw. 1287 g m-2 a-1 zu den höchsten bisher in tropischen Bergregenwäldern gemessenen Werten zählen. Der Streufall der Baumblätter stellte mengenmäßig die bedeutendste Streufraktion dar, die in allen drei Beständen eine saisonale Dynamik mit deutlich erhöhten Streumengen in der Trockenzeit zeigte. Die epiphytischen Streumengen nahmen mit dem Bestandesalter vom jungen Sekundärwald (4.8 g m-2 a-1) über den älteren Sekundärwald (12 g m-2 a-1) zum Altbestand ( 78.5 g m-2 a-1) zu, waren aber im Vergleich zu den übrigen Streufraktionen gering.Ein Vergleich der Epiphytenbiomasse der drei Bestände zeigte mit steigendem Bestandesalter einen zunehmenden Epiphytenbewuchs in der Kronenregion. Die Schätzung der gesamten epiphytischen Biomasse auf Bestandesebene (inklusive Kronenhumus) ergab 160 kg ha-1 im jungen Sekundärwald, 520 kg ha-1 im älteren Sekundärwald und etwa 3400 kg ha-1 im Altbestand.Mikrometeorologische Untersuchungen deuteten auf einen geringen Nebeleinfluß und ließen eine ausgeprägte Trockenzeit erkennen. Im Bestandesinneren wiesen alle drei Waldstadien vergleichbare Vertikalprofile von Lufttemperatur und Luftfeuchte auf. Die größere Epiphytenbiomasse des Altbestandes führte zu keiner meßbaren Erhöhung der Luftfeuchte im Bestandesinneren.Der Bestandesniederschlag zeigte mit Werten zwischen 69% und 75% des Freilandniederschlags im Jahresmittel nur geringe Unterschiede zwischen den Beständen. Wesentlich größer waren die Bestandesunterschiede hingegen beim Stammablauf, der im jungen und älteren Sekundärwald im Jahresmittel 16% bzw. 17% erreichte, während im Altbestand nur 2% gemessen wurden. Die Interzeption betrug im Altbestand 25% und lag deutlich über den im jungen Sekundärwald (15%) und im älteren Sekundärwald (9%) ermittelten Werten. Diese Befunde werden auf Unterschiede in der Struktur und Exposition der Bestände zurückgeführt.Beregnungsexperimente im Labor zeigten, daß bestimmte epiphytische Moosarten (Leptodontium exasperatum) mehr als das Siebenfache ihres Trockengewichts an Wasser speichern können. Die in der Kronenregion des Altbestandes bei dieser Art gemessenen Wassergehalte waren jedoch selbst in der Regenzeit deutlich niedriger (406%). Aufgrund geringer Verdunstungsraten ist die Bedeutung epiphytischer Moose im Interzeptionsprozeß vermutlich eher als gering einzuschätzen, da die Speicherentleerung langsam verläuft. Zur recht geringen Bedeutung trägt auch die heterogene Verteilung der Epiphyten und, in den Sekundärwäldern, deren verhältnismäßig geringe Biomasse bei. Eine für den Altbestand durchgeführte hydrologische Modellrechnung, nach der die epiphytischen Moose mit nur 6% an der Gesamtinterzeption des Bestandes beteiligt sind, bestätigt diese Ergebnisse.Nährstoffe (mit Ausnahme von Nitrat) wurden im Jahresmittel vom Freilandniederschlag zum Nettoniederschlag während der Kronenpassage angereichert. Die bestandesinternen Nährstoffflüsse ließen in der Gesamtmenge der mit dem Niederschlag transportierten Nährstoffe nur geringe Unterschiede zwischen den drei Waldsstadien erkennen. Beim Stammabfluß zeigten sich jedoch deutliche Unterschiede, wobei hohe Nährstoffflußraten in den Sekundärwäldern auffallen. Dies wird in erster Linie auf die hohe Stammdichte und die Kronenstruktur in den Sekundärwäldern zurückgeführt, während der Einfluß der Epiphyten auf die Nährstoffflüsse als eher gering einzuschätzen ist. Die Nährstofftransfers mit der Streu epiphytischer Moose und Flechten sind im Vergleich zu den über die Blattstreu transportierten Stoffmengen ebenfalls niedrig.Die Ergebnisse zeigen, daß die Folgen einer Konversion von Primärwald für den Wasser- und Nährstoffhaushalt auch nach 40jähriger sekundärer Waldsukzession noch deutlich erkennbar sind. Hierbei ist die Rolle der Epiphyten jedoch eher als gering einzuschätzen. Die gefundenen Unterschiede im Kronenwasserumsatz und Nährstoffkreislauf lassen sich im Wesentlichen auf strukturelle Charakteristika im Baumbestand der untersuchten Waldstadien zurückführen.

Human–wildlife conflicts (HWC) arising from fruit bats eating commercial fruits is a worsening problem worldwide and is epitomized by the Mauritian flying fox (Pteropus niger), a species threatened with extinction yet repeatedly mass-culled since 2015. Non-lethal solutions for dealing with this HWC are needed, which are rooted in the evidence available. In this study, we tracked the movements of 12 flying fox individuals over two years in order to document the animal’s movement ecology, with a view to deriving recommendations to alleviate the ensuing HWC. We found that flying foxes prefer to forage and roost in forested areas located at elevations < 250 m. However, during the fruiting season of commercial trees, the animals tended to roost closer to and forage more often on commercial fruits during the early hours of the night. These findings have several implications for the improvement of commercial fruit protection, which should in turn alleviate HWC, notably through informing management to take into consideration the spatio-temporal expression of flying fox foraging.

Second-growth forests of the Mexican tropics are reservoirs of timber species similar to old-growth forest: Perspectives for sustainable forest management

Tropical forests are becoming increasingly alien-dominated through the establishment of timber plantations and secondary forests. Despite widespread recognition that afforestation results in increased evapotranspiration and lower catchment yields, little is known of the impacts of timber plantations on water balance relative to native forest. Native forest trees have been claimed to use water conservatively and enhance groundwater recharge relative to faster-growing alien species, and this argument should motivate native forest preservation and restoration. However, data have been available primarily for leaf-level gas exchange rather than for whole-plant and stand levels. We measured sap flow of dominant tree and tree fern species over eight weeks in native Metrosideros polymorpha forest and adjacent alien timber plantations on the island of Hawai'i and estimated total stand transpiration. Metrosideros polymorpha had the lowest values of sap flux density and whole-tree water use (200 kg m(-2) sapwood d(-1), or 8 kg/d for trees of 35 cm mean diameter at breast height, D), substantially less than timber species Eucalyptus saligna or Fraxinus uhdei (33 and 34 kg/d for trees of 73 and 30 cm mean D, respectively). At the stand level, E. saligna and F. uhdei trees had three- and ninefold higher water use, respectively, than native M. polymorpha trees. Understory Cibotium tree ferns were most abundant in M. polymorpha-dominated forest where they accounted for 70% of water use. Overall, F. uhdei plantation had the highest water use at 1.8 mm/d, more than twice that of either E. saligna plantation or M. polymorpha forest. Forest water use was influenced by species composition, stem density, tree size, sapwood allocation, and understory contributions. Transpiration varied strongly among forest types even within the same wet tropical climate, and in this case, native forest had strikingly conservative water use. Comparisons of vegetation cover in water use should provide additional resolution to ecosystem valuation and land management decisions.