Tree Habitat Research Articles

Choosing an appropriate planting scheme for intensive apple gardens

This article describes the intensive planting of varieties of apples belonging to local and foreign selection in soil and climatic conditions of Tashkent region in 4 different (4.0x2.5; 4.0x2.0; 4.0x1.5 and 4.0x1.0 m.) planting schemes, mainly in varieties with low tree height and small branch size, the effect of planting schemes on tree habitat is small. In contrast, in varieties with high biological growth rate, the effect of planting schemes was found to be high. However, data have shown that as the length of the main branches in apple tree trees decreases, they cause an increase in ring-shaped fruit branches, which in turn affects the yield in the trees by reducing the feeding area.

Woody Species Stand Structure and Regeneration Status in Long Jack (Eurycoma longifolia Jack) Habitat in Batang Lubu Sutam Forest, Padang Lawas, North Sumatra

Long jack (Eurycoma longifolia) is a medicinal plant that has become a common target for exploitation, leading to a population decline in natural forests. This study aimed to determine the stand structure and regeneration status of E. longifolia tree habitat in Batang Lubu Sutam Forest, Padang Lawas, North Sumatra. The research was performed through vegetation analysis using a purposive sampling technique with a randomized sample plot based on the presence of E. longifolia. A total of 181 plots were established in this study. The results showed that the horizontal structure of tree species in the research area had an inverted J-shape pattern, indicating that the number of trees decreased as the diameter increased. The vertical structure showed that all strata were found in the research location, dominated by stratum C. This condition indicated that the forest was in good condition. The regeneration status of 48 species in the location showed different categories. Thirty species (62.50%) were classified as good regeneration, ten species (18.75%) as new regeneration, and four species (8.30%) as poor and no regeneration. The high proportion of trees with good regeneration showed that the forest community could survive despite environmental or anthropogenic stress. Keywords: long jack (Eurycoma longifolia), regeneration, species composition, vegetation structure

Species Diversity and Distribution Pattern of Heritage Trees in the Rapidly-Urbanizing Province of Jiangsu, China

Heritage trees have important ecological, historical, and landscape values in cities. Rapid urbanization may cause dramatic change of ecosystem functions of cities, thereby inevitably affecting the growth performance of ancient trees. However, few studies have explored their species diversity and spatial differentiation on the medium scale in the scenario of urbanization in China. Here, we took Jiangsu Province in China, with developed economy in recent decades, as a typical case. Based on the provincial forest inventory data, we addressed the abundance, species richness, tree density, and species diversity of ancient trees in 13 cities, and their tree habitat, growth status, and tree age, as well. Then, we compared the spatial differentiation of tree attributes by 13 districts and nine tree habitats. We also applied detrended correspondence analysis (DCA) and redundancy analysis (RDA) to determine the leading factor influencing their distribution pattern. The 7678 heritage trees in Jiangsu belonged to 215 species. More than half of the trees were native with domination by Ginkgo biloba. Villages and farmlands accommodated the most heritage trees while parks and gardens harbored the most species. This indicates that sparsely-populated rural community and scenic areas with open space are conducive to accommodating more urban heritage trees. The tier 3 heritage trees (100–299 years) accounted for about 80% of the total. Overall, most ancient trees in Jiangsu grew well. The species diversity index (H) of 13 cities was between 1.98 and 3.39. The H value among the 13 cities was largely affected by elevation range shift, while the tree density by GDP per capita. DCA showed that the ratio of unique species was >40%, and that dominant species presented little habitat preference. Therefore, species diversity among different cities are affected by climate and topography, as well as human factors. With the accelerating urbanization process, tree habitat, cultural tradition, and urban history should be taken into consideration for management and conservation of heritage trees in the future.

Identifying old Norway spruce and Scots pine trees by morphological traits and site characteristics

ABSTRACT Old trees are important for biodiversity, and the process of their identification is a critical process in their conservation. However, determining the tree age by core extraction, ring counts, and eventually, cross-dating by means of dendrochronology is labor-intensive and expensive. Here we examine the alternative method of estimating determining tree age by visual characteristics for old Norway spruce and Scots pine trees. We used forest stands previously identified as “Old tree habitats” by visual criteria in Norwegian boreal forests. The efficiency of this method was tested using pairwise comparison of the age of core samples from trees within these sites, and within neighboring sites. Age regression models were constructed from morphological traits and site variables to investigate how accurately old trees can be detected. Cored trees in the Old-tree habitats were on average 41.9 years older than compared to a similar selection of trees from nearby mature forests. Several characteristics such as bark structure, stem taper and visible growth eccentricities can be used to identify old Norway spruce and Scots pine trees. Old trees were often found on less productive sites. Due to the wide range of environments included in the study, we suggest that these findings can be generalized to other parts of the boreal zone.

Polymorphisms and gene expression in the almond IGT family are not correlated to variability in growth habit in major commercial almond cultivars.

Almond breeding programs aimed at selecting cultivars adapted to intensive orchards have recently focused on the optimization of tree architecture. This multifactorial trait is defined by numerous components controlled by processes such as hormonal responses, gravitropism and light perception. Gravitropism sensing is crucial to control the branch angle and therefore, the tree habit. A gene family, denominated IGT family after a shared conserved domain, has been described as involved in the regulation of branch angle in several species, including rice and Arabidopsis, and even in fruit trees like peach. Here we identified six members of this family in almond: LAZY1, LAZY2, TAC1, DRO1, DRO2, IGT-like. After analyzing their protein sequences in forty-one almond cultivars and wild species, little variability was found, pointing a high degree of conservation in this family. To our knowledge, this is the first effort to analyze the diversity of IGT family proteins in members of the same tree species. Gene expression was analyzed in fourteen cultivars of agronomical interest comprising diverse tree habit phenotypes. Only LAZY1, LAZY2 and TAC1 were expressed in almond shoot tips during the growing season. No relation could be established between the expression profile of these genes and the variability observed in the tree habit. However, some insight has been gained in how LAZY1 and LAZY2 are regulated, identifying the IPA1 almond homologues and other transcription factors involved in hormonal responses as regulators of their expression. Besides, we have found various polymorphisms that could not be discarded as involved in a potential polygenic origin of regulation of architectural phenotypes. Therefore, we have established that neither the expression nor the genetic polymorphism of IGT family genes are correlated to diversity of tree habit in currently commercialized almond cultivars, with other gene families contributing to the variability of these traits.

The efficiency of retention measures in continuous-cover forestry for conserving epiphytic cryptogams: A case study on Abies alba

Lacking structural diversity in production forests has been evidenced to decrease epiphytic bryophytes and lichens. One approach to create structurally more diverse forests is retention forestry. Only a small number of studies focused on the effectiveness of retention measures in continuous-cover forestry. Most studies have been conducted in even-aged, clear-cut based management systems and applied different approaches, but they all have in common that the retained trees have been examined for epiphytes only after harvest. Thus, it remains unclear whether these trees or even a certain tree species could take the life-boat function for epiphytes on logged sites. Thus, prior to logging, we assessed epiphytic bryophytes and lichens on potential large living retention trees, here referred to as habitat trees (HT), of Abies alba and compared the diversity pattern to nearby average trees (AT; A. alba, Fagus sylvatica or Picea abies) of smaller sizes in selectively harvested continuous-cover forests. Selection of AT was based on the average stem diameter of all trees within the stand. We found that species richness and Simpson diversity of lichens were significantly higher on HT. For bryophytes, F. sylvatica AT showed significantly higher Simpson diversity. Mixed models revealed positive effects of F. sylvatica on bryophytes, whereas large stem diameters and elevation were the driving forces for lichens. Additionally, ordinations revealed clear patterns in species composition separating between conifers and broadleaved trees, and along increasing altitude and stem diameter. Concerning HT selection, we suggest to focus rather on the tree species diversity than on stem diameter, when aiming to protect epiphytic bryophytes and lichens.

Tree-Related Microhabitats Follow Similar Patterns but are More Diverse in Primary Compared to Managed Temperate Mountain Forests

The impact of forest management on biodiversity is difficult to scrutinize along gradients of management. A step towards analyzing the impact of forest management on biodiversity is comparisons between managed and primary forests. The standardized typology of tree-related microhabitats (TreMs) is a multi-taxon indicator used to quantify forest biodiversity. We aim to analyze the influence of environmental factors on the occurrence of groups of TreMs by comparing primary and managed forests. We collected data for the managed forests in the Black Forest (Germany) and for the primary forests in the Western (Slovakia) and Southern Carpathians (Romania). To model the richness and the different groups of TreMs per tree, we used generalized linear mixed models with diameter at breast height (DBH), altitude, slope and aspect as predictors for European beech (Fagus sylvatica (L.)), Norway spruce (Picea abies (L.)) and silver fir (Abies alba (Mill.)) in primary and managed temperate mountain forests. We found congruent results for overall richness and the vast majority of TreM groups. Trees in primary forests hosted a greater richness of all and specific types of TreMs than individuals in managed forests. The main drivers of TreMs are DBH and altitude, while slope and aspect play a minor role. We recommend forest and nature conservation managers to focus: 1) on the conservation of remaining primary forests and 2) approaches of biodiversity-oriented forest management on the selection of high-quality habitat trees that already provide a high number of TreMs in managed forests based on the comparison with primary forests.

Characterisation of breeding habitat of Grizzled Giant Squirrel Ratufa macroura (Mammalia: Sciuridae) in Chinnar Wildlife Sanctuary, Western Ghats, India

The Grizzled Giant Squirrel (GGS) Ratufa macroura (Pennant, 1769) is a ‘Near Threatened’ and endemic giant squirrel distributed in southern India and Sri Lanka. In India, the species is distributed in more than 10 locations between Cauvery Wildlife Sanctuary in Karnataka in the north and Srivilliputhur Grizzled Squirrel Wildlife Sanctuary in Tamil Nadu in the south. A study was conducted in the riparian habitats of Chinnar Wildlife Sanctuary in Kerala to understand the habitat characteristics, including the drey site use of GGS. The vegetation of the GGS habitat was studied using the quadrat method, and the dreys were counted using the transects. A total of 95 species of trees were identified from the riverine vegetation, and the GGS used 36 species of trees for drey construction. Most of the dreys were found on Mangifera indica, Terminalia arjuna, Ficus microcarpa, Diospyros ebenum, and Pongamia pinnata. However, the GGS may prefer trees such as Mitragyna parviflora, Diospyros ebenum, Ficus microcarpa, Albizia procera, Acacia nilotica, and Acacia leucophloea for drey construction. The study also highlights the usage of large trees with extensive crown by the GGS for various activities such as feeding, resting, moving, and nesting, thus signifying the necessity for protecting the remaining riverine habitat at Chinnar Wildlife Sanctuary to ensure the long-term conservation of GGS. We recommend an urgent restoration by restocking with already existing, native tree species of the riverine habitat due to the extremely poor regeneration of trees in the riverine habitat that support the only population of the GGS in Kerala.

Assessing the storage potential of Australian rainforest seeds: a decision-making key to aid rapid conservation

Seed banking of rainforest species is hindered by lack of knowledge as to which species are tolerant of desiccation and freezing. We assessed 313 Australian rainforest species for seed banking suitability by comparing the germination percentage of fresh seeds to seeds dried at 15% RH and seeds stored at −20 °C after drying. We then compared desiccation responses to environmental, habit, fruit and seed characteristics to identify the most useful predictors of desiccation sensitivity. Of 162 species with ≥ 50% initial germination, 22% were sensitive to desiccation, 64% were tolerant and 10% were partially tolerant; the responses of 4% were uncertain. Of 107 desiccation tolerant species tested for response to freezing, 24% were freezing sensitive or short-lived in storage at −20 °C. Median values for fresh seed moisture content (SMC), oven dry weight (DW) and the likelihood of desiccation sensitivity (PD-S) were significantly greater for desiccation sensitive than desiccation tolerant seeds. Ninety-four to 97% of seeds with SMC < 29%, DW < 20 mg or PD-S < 0.01 were desiccation tolerant. Ordinal logistic regression of desiccation response against environmental, habit, fruit and seed characteristics indicated that the likelihood of desiccation sensitivity was significantly increased by a tree habit, fleshy fruit, increasing fresh SMC and increasing PD-S. The responses observed in this study were combined with earlier studies to develop a simple decision key to aid prediction of desiccation responses in untested rainforest species.

Water deficiency of little-leaf linden poly-metallic contamination

A high level of environmental pollution identifies Sterlitamak industrial center (PreUral, Russia). Among human-made emissions, particulate matter (including heavy metals), nitrogen dioxide, ammonia and formaldehyde dominate. We studied the water regime of little-leaf linden (Tilia cordata Mill.) trees in habitats with diverse pollution levels from 2010 to 2018. There have been significant changes in the indicators of water deficiency of linden leaves under pollution conditions. Regardless of the category of life state, the linden trees had a slight water deficit under control, while the healthy and weakened linden trees had a high-water deficit under pollution conditions. The results point that under polluted conditions, as the temperature increases and the air’s relative humidity decreases, the water consumption of linden leaves increases. The maximum water deficiency is in the daytime (13-15 hours). At night, the flow of water is not covered by the inflow, so the following day, the morning begins with some water lack. Thus, in a polluted environment, significant changes in the water deficit of the linden trees are associated with reduced soil moisture, increased transpiration, and worsened of stand life states.

Genomic insights into the fast growth of paulownias and the formation of Paulownia witches' broom

Paulownias are among the fastest growing trees in the world, but they often suffer tremendous loss of wood production due to infection by Paulownia witches' broom (PaWB) phytoplasmas. In this study, we have sequenced and assembled a high-quality nuclear genome of Paulownia fortunei, a commonly cultivated paulownia species. The assembled genome of P. fortunei is 511.6 Mb in size, with 93.2% of its sequences anchored to 20 pseudo-chromosomes, and it contains 31 985 protein-coding genes. Phylogenomic analyses show that the family Paulowniaceae is sister to a clade composed of Phrymaceae and Orobanchaceae. Higher photosynthetic efficiency is achieved by integrating C3 photosynthesis and the crassulacean acid metabolism pathway, which may contribute to the extremely fast growth habit of paulownia trees. Comparative transcriptome analyses reveal modules related to cambial growth and development, photosynthesis, and defense responses. Additional genome sequencing of PaWB phytoplasma, combined with functional analyses, indicates that the effector PaWB-SAP54 interacts directly with Paulownia PfSPLa, which in turn causes the degradation of PfSPLa by the ubiquitin-mediated pathway and leads to the formation of witches' broom. Taken together, these results provide significant insights into the biology of paulownias and the regulatory mechanism for the formation of PaWB.

Large trees as a key factor for bird diversity in spruce-dominated production forests: Implications for conservation management

Large trees (also termed veteran trees or habitat trees) are keystone structures for biodiversity worldwide. Retention forestry aims to keep large trees in production stands to support biodiversity. Nevertheless, there is insufficient information about the effect of large trees on biodiversity and how many large trees should be left in different types of stands, including spruce-dominated production forest. We aimed to investigate the influence of large trees on birds (included generalist and specialist species) in spruce-dominated production forest throughout the Czech Republic while taking into consideration effects of stand age, tree species composition, and distance to a clearing. At 20 study sites (each 600 ha), all trees with diameter at breast height (DBH) ≥ 70 cm were exhaustively searched. We then localized sampling plots representing a gradient of large tree numbers from zero to maximum on each plot. Birds were sampled using point count method in breeding seasons 2018 and 2019. Bird assemblages were analysed using generalized linear mixed models with Poisson error distribution. The total number of birds, number of generalist species, and number of specialist species increased significantly with the number of broadleaved trees ≥ 70 cm DBH. Furthermore, tree species diversity positively affected generalist species and negatively influenced specialist species. Our results suggest that 5 broadleaved trees ≥ 70 cm DBH/ha greatly improve bird diversity in spruce-dominated production forests and forest management should be adapted to reach ≥ 5 native, large, broadleaved trees to improve structural diversity of spruce-dominated production forests.

Fabaceae leaf morphogenetic evolution: the leaf-lamina architectural variation in the Fabaceae flora of Indian Western Ghats, compared with that genetically characterized in the Fabaceae model species Pisum sativum and Medicago truncatula

A total of 745 Fabaceae species-516 Faboideae, 192 Caesalpinioideae, 21 Detarioideae, 14 Cercidoideae and 2 Dialioideae species-, that inhabit Indian Western Ghats region, were characterized for their leaf lamina morphology. In all 16 leaf lamina types were identified, 12 of which are known and genetically understood in the model Faboideae Fabaceae species Pisum sativum and Medicago truncatula. Among the 16 leaf types, 5 were of simple type, 6 of unipinnate imparipinnate type, 2 of unipinnate paripinnate type, 2 of bipinnate paripinnate type and 1 of bipinnate imparipinnate type. Unifoliate leaves in Faboideae species were either in the form a simple tendril or a simple pinna. None of the Faboideae-species of tree habit was observed to produce unifoliate leaves. There were no herb species in other subfamilies that formed unifoliate leaves. Faboideae species bearing bipinnate leaves were absent. In Caesalpinioideae, different species produced all the 4 types of compound leaves. Cercidoideae and Detarioideae species were observed to bear largely unifoliate or bifoliate compound leaves. Simple pinnae in Cercidoideae and Detarioideae differed from those in Faboideae by having multiple primary veins. All leaf types were assigned pathway of origin. Whereas it is known that types leaf evolved from unipinnate imparipinnate leaf in Faboideae, it is suggested that unifoliate leaves in Cercidiodeae and Mimosoideae evolved from bipinnate paripinnate leaf types genotypes or vice versa. Evidence was found in favour of monophyletic origin followed by divergence in the genetic mechanisms, in the evolutionary process of leaf lamina architectural polymorphism in Fabaceae. Several directions of new research on the genetics of leaflamina morphogenesis in Fabaceae were identified.

Pollen Sources in Honey Bee (Apis mellifera) Diet in Ellis County, Kansas

Pollinators are integral to plant ecology as well as to worldwide food availability and security. Understanding the diet of honey bees (Apis mellifera) and knowing how human-driven land use change impacts the nutrition of managed honey bees is important in pollinator conservation efforts and can contribute towards combating recent pollinator declines. The objective of this study was to determine sources of forage for honey bees across different land use types in Ellis County, Kansas, through pollen analysis and taxonomic identification. Replicate study colonies were placed in three separate land use types: urban, cropland, or native/semi-native prairie. Pollen was sampled every 7 to 14 days throughout a growing season (April 1 to September 30) to identify key resources and their availability throughout time and space. Images of pollen from 110 species are presented. Pollen abundance (mass) varied greatly throughout time and across treatments, although urban colonies trended toward higher pollen abundance and cropland colonies trended toward reduced pollen abundance. Pollen from 41 different plant taxa was collected from experimental hives, with willows (Salix) and clovers (Melilotus/Trifolium) observed in abundance among all land use treatments. Unique distinctions among floral resources utilized in the three land use treatments included the abundance of trees in urban habitat, the prevalence of weedy species in cropland habitat, and the lack of grass pollen collected in cropland habitat. These results provide insight on available resources as well as honey bee preferences and foraging behaviors. Understanding the availability of floral resources in prairies can help to inform conservation decisions and improve understanding of community ecology and health of native pollinators in prairies.

Daya Tarik Keanekaragaman Burung di Jalur Hijau Jalan Kota Yogyakarta

Urban greenery plays an important role in providing a biodiversity habitat of vegetation and birds as biotics in the urban ecosystem. The biodiversity can show attractions in Yogyakarta city as a tourism destination in Indonesia. This research was conducted on three types of roads of the secondary artery (SA), secondary collector (SC), and local (L). The bird diversity depended on tree greenery as its habitat and food source. This research aimed (1) to analyze bird diversity on the roadside greenery in Yogyakarta City, and (1) to reveal the attraction of birds on the urban greenery as a tourism attraction. The sample units were selected by the method of stratified random sampling. The bird observation was used by the method of transect line conducted on the three categories of roads in Yogyakarta City. The bird diversity was analyzed by Shannon-Wiener's (H') index diversity, and bird activity was descriptively analyzed. The number of birds found in the greenery was 685 belong to 12 species. The diversity indexes (H') of the birds on the roads of the secondary artery (SA), secondary collector (SC), and local (L) categories were 0.697 (low), 1.001 (medium), and 1.246 (medium). The index shows the equal quality of the bird attractions in the city. The low-medium of index value should be improved to reach a high H'. The improvement should be carried out by landscape planning for urban tourism through planting food source trees or habitat trees for birds on the urban greenery of Yogyakarta. The strength of the urban attraction of birds was also supported by species diversity, conservation status, bird activity, habitat trees, and the ecological function of urban trees on the roadside greenery of Yogyakarta city.&#x0D; Keywords: bird diversity, roadside greenery, urban attraction, urban greenery, Yogyakarta

Buffer Zone Management Impact on Birds Assemblage in the High Nature Value Farmland (HNVf) : a study case on Meru Betiri National Park

The study aims to analyze the vertical and horizontal distribution of bird communities in agricultural areas and their interactions with the conservation area in MBNP. Research is carried out in agricultural areas in the Buffer zone, Rehabilitation Zone, and on the edge of the plantation. The research location was determined at 37 points: Rajekwesi (4), Sukamade (12), Bandealit (8), Wonoasri (5), Andongrejo (3), Sanenrejo (5). We applied the point count method (r = 17.5 m) in this study, where each point is at least 100-150 meters apart. In the study, 74.6% of records were birds with agricultural specialties and 71.30% of individuals using tree habitats. Birds with specialization in agriculture were found in large numbers related to the protection provided by the TNMB conservation area to bird habitat. Sukamade is the area with the highest number of records. As many as 40.10% were found in tree habitats. Followed by Seedling (16.28%), Pole (15.93%), Flying over (15.76%), and Sapling (11.90%).

Buffer Zone Management Impact on Birds Assemblage in the High Nature Value Farmland (HNVf) : a study case on Meru Betiri National Park

This study aims to analyze the distribution of bird communities and the impact of vegetation on bird habitat preferences in the buffer zone. Research is carried out in agricultural areas in the Buffer zone, Rehabilitation Zone, and on the edge of the plantation. The research location was determined at 37 points: Rajekwesi (4), Sukamade (12), Bandealit (8), Wonoasri (5), Andongrejo (3), Sanenrejo (5). We applied the point count method (r = 17.5 m) in this study, where each point is at least 100-150 meters apart. In the study, 74.6% of records were birds with agricultural specialities and 71.30% of individuals on tree habitats. Birds with specialization in agriculture were found in large numbers related to the protection provided by the TNMB conservation area to bird habitat. Sukamade is the area with the highest number of records. As many as 40.10% were found in tree habitats followed by seedling (16.28%), poles (15.93%), flying over (15.76%), and sapling (11.90%)

Fractal dimension of tree crowns explains species functional-trait responses to urban environments at different scales.

The evolution of form and function of trees of diverse species has taken place over hundreds of millions of years, while urban environments are relatively new on an evolutionary time scale, representing a novel set of environmental constraints for trees to respond to. It is important to understand how trees of different species, planted in these anthropogenically-structured urban ecosystems, are responding to them. Many theories have been advanced to understand tree form and function, including several that suggest the fractal-like geometry of trees is a direct reflection of inherent and plastic morphological and physiological traits that govern tree growth and survival. In this research, we analyzed the "fractal dimension" of thousands of tree crowns of many different tree species, growing in different urban environments across the United States, to learn more about the nature of trees and their responses to urban environments at different scales. Our results provide new insights regarding how tree crown fractal dimension relates to balances between hydraulic- and light-capture-related functions (e.g., drought and shade tolerance). Our findings indicate that trees exhibit reduced crown fractal dimension primarily to reduce water loss in hotter cities. More specifically, the intrinsic drought tolerance of the studied species arises from lower surface to volume ratios at both whole-crown and leaf scales, preadapting them to drought stress in urban ecosystems. Needle-leaved species showed a clear trade-off between optimizing the fractal dimension of their crowns for drought vs. shade tolerance. Broad-leaved species showed a fractal crown architecture that responded principally to inherent drought tolerance. Adjusting for the temperature of cities and intrinsic species effects, the fractal dimension of tree crowns was lower in more heavily urbanized areas (with greater paved area or buildings) and due to crowns conflicting with utility wires. With expectations for more urbanization and generally hotter future climates, worldwide, our results add new insights into the physiological ecology of trees in urban environments, which may help humans to provide more hospitable habitats for trees in urbanized areas and to make better decisions about tree selection in urban forest management.

Nesting tree selection by scattered heronry birds of drought prone Northern Bankura, West Bengal, India: preference of Phoenix sylvestris near wetland-associated habitats

The present study was conducted in the Gangajalghati block of Northern Bankura, India, to investigate the habitat and nest tree preference of three colonial waterbirds viz. Nycticorax nycticorax, Egretta garzetta, and Ardeola grayii. The study sites were surveyed for 20 months between 2017 and 2020. A total of 817 nests with an average of 204 per year were recorded on 13 tree species. Nycticorax nycticorax showed the maximum nest count followed by Egretta garzetta and Ardeola grayii. Relative abundance data revealed Phoenix sylvestris as the most abundant species (45%) of the area and harbours the highest proportion (33%) of nests. Pooled nest count data showed significantly higher (p &lt; 0.01) total nest counts in the wetland associated habitats than others. The study observed more nest density of all three species near a cluster of small ponds than in a large water body. Year-wise difference in cumulative nest number and mean nest abundance of all three species was statistically insignificant. The interspecific nearest neighbour on Phoenix sylvestris were Egretta garzetta (88.37%) for Nycticorax nycticorax and Nycticorax nycticorax (83.25%) for Egretta garzetta and Ardeola grayii. Further, the study evaluated the impact of two tropical cyclones (Amphan and Fani) on the total nest count and found that more than 75% nests (p &lt; 0.05) were destroyed by the mighty Amphan in May 2020. The study provides a baseline data on nesting trees and habitat preference of three species of heronry birds from Northern Bankura.

Reproductive interference hampers species coexistence despite conspecific sperm precedence.

Negative interspecific mating interactions, known as reproductive interference, can hamper species coexistence in a local patch and promote niche partitioning or geographical segregation of closely related species. Conspecific sperm precedence (CSP), which occurs when females that have mated with both conspecific and heterospecific males preferentially use conspecific sperm for fertilization, might contribute to species coexistence by mitigating the costs of interspecific mating and hybridization. We discussed whether two species exhibiting CSP can coexist in a local environment in the presence of reproductive interference. First, using a behaviorally explicit mathematical model, we demonstrated that two species characterized by negative mating interactions are unlikely to coexist because the costs of reproductive interference, such as loss of mating opportunity with conspecific partners, are inevitably incurred when individuals of both species are present. Second, we experimentally examined differences in mating activity and preference in two Harmonia ladybird species known to exhibit CSP. These behavioral differences may lead to local extinction of H. yedoensis because of reproductive interference by H. axyridis. This prediction is consistent with field observations that H. axyridis uses various food sources and habitats whereas H. yedoensis is confined to a less preferred prey item and a pine tree habitat. Finally, by a comparative approach, we observed that niche partitioning or parapatric distribution, but not sympatric coexistence in the same habitat, is maintained between species with CSP belonging to a wide range of taxa, including vertebrates and invertebrates living in aquatic or terrestrial environments. Taken together, it is possible that reproductive interference may destabilize local coexistence even in closely related species that exhibit CSP.