Vegetation analysis of the Forest Park of Pocut Meurah Intan (THRPMI), Seulawah Subdistrict, Aceh Besar, Aceh Province

A study entitled “Vegetation Analysis of the Forest Park of Pocut Meurah Intan, Seulawah Subdistrict of Aceh Besar, Aceh Province” has been conducted since April 2019 until November 2019. A transect method and squares were used in this study. The transect method was used to record species composition throughout the observation stations (inventory of species), including stands of pine (Pinus merkusii) with ten stations transect, stands of eucalyptus (Eucalyptus urophylla), stands of cacao (Theobroma cacao), and natural forests within a radius of 2 km around the THRPMI office. The squares method was used to record the species in the same locations to replicate each station by ten squares of samples for vegetation analysis. The parameters measured in the field were frequency, density, and dominance of each species. Analysis of vegetation covered Importance Values (IV), Diversity Index (H ’), and the Similarity Index (SI). Results showed that there were 49 familia found with the composition of species in the entire observation stations comprising of 111 species with 58 species of trees, 12 species of shrubs, and 41 species of herbs. Additionally, the results showed that the species of vegetation with the highest IV were coarse grass (Imperata cylindrica), lawn pait (Axonopus compresus), and selasi (Vernonia cinerea) with IV of 72.01, 65.34, and 57.24, respectively. Results of analysis Species Diversity Index (H ’) showed that the Pinus merkusii had H’ of 2,134, whereas Eucalyptus urophylla had H ’of 1.965, and Theobroma cacao had H’ of 1,067. The results of the analysis of Community Similarity Index showed that all stations had the same relative SI of 75%. It can be concluded that the species composition of the study area dominated by tree species, species diversity index (H ’) in all observation stations varied ranging from 1.067 to 2.134, and the relative Community Similarity Index was 75%.

Community similarity and species overlap between habitats provide insight into the deep reef refuge hypothesis

The deep reef refuge hypothesis (DRRH) postulates that mesophotic coral ecosystems (MCEs) may provide a refuge for shallow coral reefs (SCRs). Understanding this process is an important conservation tool given increasing threats to coral reefs. To establish a better framework to analyze the DRRH, we analyzed stony coral communities in American Sāmoa across MCEs and SCRs to describe the community similarity and species overlap to test the foundational assumption of the DRRH. We suggest a different approach to determine species as depth specialists or generalists that changes the conceptual role of MCEs and emphasizes their importance in conservation planning regardless of their role as a refuge or not. This further encourages a reconsideration of a broader framework for the DRRH. We found 12 species of corals exclusively on MCEs and 183 exclusively on SCRs with another 63 species overlapping between depth zones. Of these, 19 appear to have the greatest potential to serve as reseeding species. Two additional species are listed under the U.S. Endangered Species Act, Acropora speciosa and Fimbriaphyllia paradivisa categorized as an occasional deep specialist and a deep exclusive species, respectively. Based on the community distinctiveness and minimal species overlap of SCR and MCE communities, we propose a broader framework by evaluating species overlap across coral reef habitats. This provides an opportunity to consider the opposite of the DRRH where SCRs support MCEs.

Microbial and Geochemical Evidence of Permafrost Formation at Mamontova Gora and Syrdakh, Central Yakutia

Biotracers marking the geologic history and permafrost evolution in Central Yakutia, including Yedoma Ice Complex (IC) deposits, were identified in a multiproxy analysis of water chemistry, isotopic signatures, and microbial datasets. The key study sections were the Mamontova Gora and Syrdakh exposures, well covered in the literature. In the Mamontova Gora section, two distinct IC strata with massive ice wedges were described and sampled, the upper and lower IC strata, while previously published studies focused only on the lower IC horizon. Our results suggest that these two IC horizons differ in water origin of wedge ice and in their cryogenic evolution, evidenced by the differences in their chemistry, water isotopic signatures and the microbial community compositions. Microbial community similarity between ground ice and host deposits is shown to be a proxy for syngenetic deposition and freezing. High community similarity indicates syngenetic formation of ice wedges and host deposits of the lower IC horizon at the Mamontova Gora exposure. The upper IC horizon in this exposure has much lower similarity metrics between ice wedge and host sediments, and we suggest epigenetic ice wedge development in this stratum. We found a certain correspondence between the water origin and the degree of evaporative transformation in ice wedges and the microbial community composition, notably, the presence of Chloroflexia bacteria, represented by Gitt-GS-136 and KD4-96 classes. These bacteria are absent at the ice wedges of lower IC stratum at Mamontova Gora originating from snowmelt, but are abundant in the Syrdakh ice wedges, where the meltwater underwent evaporative isotopical fractionation. Minor evaporative transformation of water in the upper IC horizon of Mamontova Gora, whose ice wedges formed by meltwater that was additionally fractionated corresponds with moderate abundance of these classes in its bacterial community.

Analysing the distance decay of community similarity in river networks using Bayesian methods

The distance decay of community similarity (DDCS) is a pattern that is widely observed in terrestrial and aquatic environments. Niche-based theories argue that species are sorted in space according to their ability to adapt to new environmental conditions. The ecological neutral theory argues that community similarity decays due to ecological drift. The continuum hypothesis provides an intermediate perspective between niche-based theories and the neutral theory, arguing that niche and neutral factors are at the opposite ends of a continuum that ranges from competitive to stochastic exclusion. We assessed the association between niche-based and neutral factors and changes in community similarity measured by Sorensen’s index in riparian plant communities. We assessed the importance of neutral processes using network distances and flow connection and of niche-based processes using Strahler order differences and precipitation differences. We used a hierarchical Bayesian approach to determine which perspective is best supported by the results. We used dataset composed of 338 vegetation censuses from eleven river basins in continental Portugal. We observed that changes in Sorensen indices were associated with network distance, flow connection, Strahler order difference and precipitation difference but to different degrees. The results suggest that community similarity changes are associated with environmental and neutral factors, supporting the continuum hypothesis.

Microbial Community Composition in Municipal Wastewater Treatment Bioreactors Follows a Distance Decay Pattern Primarily Controlled by Environmental Heterogeneity

Understanding the spatiotemporal patterns of biodiversity is a central goal of ecology. The distance decay of community similarity is one of the spatial scaling patterns observed in many forms of life, including plants, animals, and microbial communities.

The secrets to domestic bliss – Partner fidelity and environmental filtering preserve stage-specific turtle ant gut symbioses for over 40 million years

BackgroundGut microbiomes can vary across development, a pattern often found for insects with complete metamorphosis. With varying nutritional need and distinct opportunities for microbial acquisition, questions arise as to how such ‘holometabolous’ insects retain helpful microbes at larval and adult stages. Ants are an intriguing system for such study. In a number of lineages adults digest only liquid food sources, while larvae digest solid foods. Like some other social insects, workers and soldiers of some ant species engage in oral-anal trophallaxes, enabling microbial transfer among siblings. But do queens, the typical colony founding caste, obtain symbionts through such transfer? Does this enable transgenerational symbiont passage? And does the resulting partner fidelity promote the evolution of beneficial symbionts? Furthermore, how might such adult-centric biology shape larval microbiomes? To address these questions, we characterized symbiotic gut bacteria across 13 species of Cephalotes turtle ants, with up to 40-million years of divergence. Adding to the prior focus on workers we, here, study underexplored castes and stages including queens, soldiers, and larvae, by performing 16S rRNA qPCR, amplicon sequencing, and phylogenetic classification.ResultsWe show that adult microbiomes are conserved across species and largely across castes. Nearly 95% of the bacteria in adults have, thus far, been found only in Cephalotes ants. Furthermore, the microbiomes from most adults exhibit phylosymbiosis, a trend in which microbiome community similarity recapitulates patterns of host relatedness. Additionally, an abundant, adult-enriched symbiont cospeciates with some Cephalotes. Evidence here suggests that these partner fidelity patterns extend from transgenerational symbiont transfer through alate gyne dispersal and subsequent colony-founding by queens. Like adults, larvae of Cephalotes species exhibit strong microbiome conservation. Phylosymbiosis patterns are weaker, however, with further evidence elevating environmental filtering as a primary mechanism behind such conservation. Specifically, while adult-enriched symbionts are found in most larvae, symbionts of older larvae are highly related to free-living bacteria from the Enterobacteriaceae, Lactobacillales, and Actinobacteria.ConclusionsOur findings suggest that both partner fidelity and conserved environmental filtering drive stable, stage-specific, social insect symbioses. We discuss the implications for our broader understanding of insect microbiomes, and the means of sustaining a beneficial microbiome.

STRUKTUR DAN KOMPOSISI VEGETASI SEBAGAI DASAR RESTORASI DEGRADASI HUTAN DI KAWASAN PERLINDUNGAN BLOK SINTANG PT FINNANTARA INTIGA

This study aims to examine the composition and structure of the vegetation in the protected forest area of PT Finnantara Intiga's Sintang block and determine the pattern of forest restoration and the types of vegetation that will be used for restoration of degraded forests. This research was conducted at PT Finnantara Intiga Sintang Block which is located in five land cover areas, of which three are reference secondary swamp forest (KPPN, KPSL and river border) and two areas are degraded forest (shrub and open land). This study uses a survey method with a line plot system. The sample was determined by means of purposive sampling. Based on the results of research data analysis, the number of species found at all levels at the KPSL location was nine species, at the KPPN location there were eleven species, at the River Border location there were eight species, at the Semak Belukar location there were seven species and at the Open Land location there were four species. In general, the horizontal structure of forest stands in damaged forest ecosystems is below the horizontal structure of natural forest stands as a reference. This shows that the level of vegetation density at the location of shrubs and open land has decreased so that forest restoration measures are needed to increase the density closer to natural forest ecosystems that have not been damaged. The pattern of forest restoration for scrub areas and open land referring to the Guidelines for Restoration in Conservation Areas (JICA, 2014) is natural succession. The pattern of forest restoration that will be implemented must take into account the physical conditions of the field and local socio-cultural considerations based on stakeholder considerations. The type of vegetation for enrichment and planting activities at the shrub location refers to the KPSL location as a reference because it tends to have similarities with the community similarity index of 52.03%. The type of vegetation for enrichment and planting activities on open land locations refers to the KPPN location as a reference because it tends to have similarities with the community similarity index of 52.17%. Keywords: Composition, forest degradation, restoration, structureAbstrakPenelitian ini bertujuan untuk mengkaji komposisi dan struktur vegetasi di kawasan hutan perlindungan blok Sintang PT Finnantara Intiga serta menentukan pola pemulihan hutan dan jenis vegetasi yang akan digunakan untuk restorasi hutan terdegradasi. Penelitian ini dilaksanakan di PT Finnantara Intiga Blok Sintang yang terletak di lima areal tutupan lahan, dimana tiga areal sebagai hutan rawa sekunder referensi (KPPN, KPSL dan sempadan sungai) dan dua areal di hutan yang terdegradasi (semak belukar dan lahan terbuka). Penelitian ini menggunakan metode survey dengan cara jalur berpetak. Sampel ditentukan dengan cara Purposive Sampling. Berdasarkan hasil analisis data penelitian, Jumlah jenis yang ditemui di semua tingkatan di lokasi KPSL ada sembilan jenis, dilokasi KPPN ada sebelas jenis, di lokasi Sempadan Sungai ada delapan jenis, di lokasi Semak Belukar ada tujuh jenis dan di lokasi Lahan Terbuka ada empat jenis. Secara umum bentuk grafik struktur horizontal tegakan hutan pada ekosistem hutan yang mengalami kerusakan berada di bawah grafik struktur horizontal tegakan hutan alam yang menjadi referensi. Hal ini menunjukkan bahwa tingkat kerapatan vegetasi pada lokasi semak belukar dan lahan terbuka mengalami penurunan sehingga diperlukan tindakan pemulihan hutan untuk meningkatkan kerapatan mendekati ekosistem hutan alam yang belum mengalami kerusakan. Pola pemulihan hutan untuk areal semak belukar dan lahan terbuka merujuk pada Pedoman Tata Cara Restorasi di Kawasan Konservasi (JICA, 2014) adalah suksesi alami. Pola pemulihan hutan yang akan dilaksanakan harus mempertimbangkan kondisi fisik lapangan dan sosial budaya setempat berdasarkan pertimbangan stakeholder. Jenis vegetasi untuk kegiatan pengkayaan dan penanaman pada lokasi semak belukar mengacu pada lokasi KPSL sebagai referensi karena kecenderungan memiliki kemiripan dengan dengan indeks kesamaan komunitas sebesar 52,03%. Jenis vegetasi untuk kegiatan pengkayaan dan penanaman pada lokasi lahan terbuka mengacu pada lokasi KPPN sebagai referensi karena kecenderungan memiliki kemiripan dengan dengan indeks kesamaan komunitas sebesar 52,17%.Kata kunci: Degradasi hutan, komposisi, restorasi, struktur

Distance decay of community similarity in river networks: a Bayesian approach

The distance decay of community similarity (DDCS) is a pattern that is widely observed in both terrestrial and aquatic environments. There are three major perspectives for explaining the DDCS. Niche-based theories argue that as environmental conditions change, species are sorted according to their ability to adapt to new environmental conditions and habitats. The ecological neutral theory argues that community similarity decays due to ecological drift. Finally, the continuum hypothesis argues that niche and neutral factors are at the opposite ends of a continuum that ranges from competitive exclusion to stochastic exclusion. Most studies on the DDCS have been conducted on terrestrial ecosytems, and there are few data for riparian plant communities in riparian ecosystems. Here we assessed the association between niche-based and neutral factors and changes in community similarity measured by Sorensen’s index. As neutral variables, we used network distances and flow connection, and as niche-based variables, we selected Strahler order differences and precipitation differences. We used a hierarchical Bayesian approach to assess which of these three perspectives best supported the results. We used a high-quality dataset composed of 338 vegetation censuses conducted in eleven river basins along a sizeable environmental gradient in continental Portugal. We observed that changes in Sorensen indices were associated with all four covariates but to different degrees. Overall, the results suggest that community similarity changes are associated with environmental and neutral factors, supporting the continuum hypothesis.

Diving Beetle (Coleoptera: Dytiscidae) Community Dissimilarity Reveals How Low Landscape Connectivity Restricts the Ecological Value of Urban Ponds

Context: Structural and functional connectivity, as subconcepts of landscape connectivity, are key factors in biodiversity conservation and management. Previous studies have focused on the consequences of connectivity for populations of terrestrial organisms, which may not be appropriate for aquatic organisms. Objectives: As landscape connectivity critically affects the potential value of ponds for biodiversity, here we used diving beetles (Dytiscidae), an indicator taxon of wetland biodiversity, to investigate how structural connectivity affects functional connectivity to aquatic invertebrates in an urban landscape. Methods: We assessed pairwise similarities of dytiscid community, i.e. the variation of species composition between clustered and isolated ponds in the Helsinki Metropolitan Area, Finland. We investigated how dytiscid community similarity is affected by Euclidean distances between ponds, as an indicator of structural connectivity. Results: We found that clustered ponds shared more species than isolated ponds. Dytiscid species community similarity responded negatively to increasing Euclidean distance between ponds. Effectively dispersing species were widely distributed across the landscape, while poor dispersers were scarcely distributed in the same landscape. Conclusions: Structural connectivity determines which species are able to disperse successfully, with poor dispersers restricted to well-connected ponds. The different responses of effective dispersers and poor dispersers to the same structural connectivity indicates that functional connectivity determines species composition. We recommend providing well-connected aquatic habitats in urban landscapes and the implementation of measures to reduce isolation of wetland assemblages. Even clustered ponds need dispersal from other habitats to ensure their contribution to urban biodiversity.