Fire-Induced Vegetation Dynamics: An In-Depth Discourse on Revealing Ecological Transformations of the Mahaban and Surrounding Forests

Assessing the spatial distribution of organic matter and total nitrogen in soil is essential for management and optimum utilization of fertilizers. Therefore, the present field experiment was conducted to evaluate the impact of different planting pattern arrangements on the spatial distribution of soil total nitrogen and organic matter content under a maize/soybean strip relay intercropping system. The planting was arranged in a manner such that soil sampling could be done from continuous maize/soybean relay strip intercropping (MS1), maize/soybean relay strip intercropping in rotation (MS2), traditional maize/soybean intercropping (MS3), sole maize (M), sole soybean (S), and fallow land (FL) from 2018 to 2020. The results showed significant variations for soil organic matter and total nitrogen content under different planting pattern arrangements of maize and soybean in the strip relay intercropping system. Across all systems, the highest soil organic matter (29.19 g/kg) and total nitrogen (10.19 g/kg) were recorded in MS2. In contrast, the lowest soil organic matter (1.69 g/kg) and total nitrogen (0.64 g/kg) were observed in FL. Soil organic matter and total nitrogen in MS2 increased by 186.45% and 164.06%, respectively, when compared with FL. Soil organic matter and total nitrogen in MS2 increased by 186.45% and 164.06%, respectively, when compared with FL. Furthermore, under MS2, the spatial distribution of soil organic matter was higher in both maize and soybean crop rows as compared with other cropping patterns, whereas the soil total nitrogen was higher under soybean rows as compared with maize in all other treatment. However, correlation analysis of the treatments showed variations in organic matter content. It can be concluded that different planting patterns can have varying effects on soil organic matter and total nitrogen distribution under the strip relay intercropping system. Moreover, it is recommended from this study that MS2 is a better planting pattern for the strip relay intercropping system, which can increase the spatial distribution of soil organic matter and total nitrogen, thereby improving soil fertility, C:N ratio, and crop production. This study will serve as a foundation towards the scientific usage of chemical fertilizers in agricultural sector.

Bovine ephemeral fever (BEF) is a fatal viral disease predominantly affecting cattle and buffaloes. Infection results in a huge economic loss, especially due to the reduction in milk production. In Pakistan. There is a dearth of information on bovine ephemeral fever. The study was designed to detect and examine the effect of bovine ephemeral fever virus on hematological parameters among cattle in Swabi district, Khyber Pakhtunkhwa, Pakistan. A total of fifty blood samples were collected from suspected cattle and scrutinized for bovine ephemeral fever virus, using nested Reverse Transcriptase Polymerase Chain Reaction (RT-PCR). Hematological parameters were analyzed using hematology and chemistry analyzer. Of the 50 blood samples, 33 representing 66% were positive for bovine ephemeral fever virus through RT-PCR. A product size of 809 bp was observed in the reaction-I, while 505bp was obtained in reaction-II. Neutrophils of infected cattle were significantly increased (10.44 ± 1.87 × 109/L) (plessthan 0.05), with a significant decrease plessthan 0.05) in lymphocytes levels (2.90 ± 0.97 × 109/L). Changes in other blood parameters were non-significant. Furthermore, there was also a significant decrease (plessthan 0.05) in serum calcium level (7.84 ± 0.16 mg/dL). We confirmed the detection of bovine ephemeral fever virus by nested reverse transcriptase polymerase chain reaction in Swabi, Khyber Pakhtunkhwa, Pakistan.

The relationship between species richness and environmental variables may change depending on habitat structure, dispersal ability, species mixing, and community adaptation to the environment. It is crucial to know how these factors regulate the environment-diversity relationship. The land molluscan fauna of the Ogasawara Islands in the West Pacific is an excellent model system to address this question because of the high species endemicity (> 90%), small area, and simple habitat structure of the islands. I examined relationships among indigenous species composition, richness, and habitat condition, and especially productivity and forest moisture on the island of Anijima. Two major communities of snails could be distinguished by detrended correspondence analysis (DCA): one group dominated in a moist habitat with high productivity, and the other group dominated in a dry habitat with low productivity. However, species richness became highest at the intermediate condition between the habitats in which the two snail communities were dominant, so that species richness showed a hump-shaped relationship with moisture and productivity. In contrast, the species richness of the snail community in the moist habitat showed a monotonically positive correlation, and that in the dry habitat showed a monotonically negative correlation with moisture and productivity. Thus, the greater species richness in intermediate moisture and productivity resulted from the ecotone effect or community overlap at the transitional areas, where faunas with different ecologies can meet in a single site. These findings suggest that hump-shaped productivity-diversity relationships in land Mollusca would reflect the ecotone effect as a result of the mixing of species adapted to either fertile habitats or sterile habitats.

Changes of Organic Matter, N, P and K Content of Soils in Red Soil Areas Under Long-Term Experiment

The toxic effects of heavy metal (HM) contamination on plant metabolism and soil microorganisms have been emphasized recently; however, little is known about the differences in soil physical, chemical, and biological properties between bulk and rhizosphere soils contaminated with HMs in forest ecosystem. The present study was conducted to evaluate the rhizosphere effect on soil properties, enzyme activities and bacterial communities associated with Robinia pseudoacacia L. along a HM contamination gradient. Soil organic matter (SOM), available nitrogen (AN) and phosphorus (AP) contents were significantly higher in rhizosphere soil than those in bulk soil at HM contaminated sites (p < 0.05). Compared to bulk soil, activities of four soil enzymes indicative of C cycle (β-glucosidase), N cycle (protease, urease) and P cycle (alkaline phosphatase) in rhizosphere soil across all study sites increased by 47.5%, 64.1%, 52.9% and 103.8%, respectively. Quantitative PCR (qPCR) and restriction fragment length polymorphism (RFLP) were used to determine the relative abundance, composition and diversity of bacteria in both bulk and rhizosphere soils, respectively. The copy number of bacterial 16S rRNA gene in bulk soil was significantly lower than that in rhizosphere soil (p < 0.05), and it had significantly negative correlations with total/DTPA-extractable Pb concentrations (p < 0.01). Alphaproteobacteria, Gammaproteobacteria and Firmicutes were the most dominant groups of bacteria at different study sites. The bacterial diversity index of Species richness (S) and Margalef (dMa) were significantly higher in rhizosphere soil compared with those in bulk soil, although no difference could be found in Simpson index (D) between bulk and rhizosphere soils (p > 0.05). Redundancy analysis (RDA) results showed that soil pH, EC, SOM and total/DTPA-extractable Pb concentrations were the most important variables affecting relative abundance, composition and diversity of bacteria (p < 0.05). Our study highlights the importance of rhizosphere effect on soil nutrient content, enzyme activity, bacterial abundance and community in HM contaminated forest soils. Further study is still required to understand the specific processes in the rhizosphere to achieve a suitable rhizosphere biotechnology for restoration of degraded forest ecosystem.

Soil erosion associated with land cultivation exerts a great impact on ecological environment. Such an impact is specific of land, crop, tillage, management and so on. This study aimed to investigate the effects of crop cultivation on water quality by comparing nutrient distribution in the sediment at Southern China. Two sedimentation sites adjacent to the uncultivated (S1) and cultivated upland (S2) were selected and samples were analyzed. Results showed that soil pH decreased with the increasing depth above 20 cm and then kept relatively stable of the both sediments. Soil organic matter, nitrogen and phosphorus contents decreased with the increasing depth. There was no significant difference between two sediments in organic matter and nitrogen contents, but the total phosphorus and extractable phosphorus contents in S2 were much higher than that in S1. The data indicated that soil eroded from S2 could possess much high potential to deteriorate water quality. Nutrient sedimentation can reflect the history of soil erosion and provide useful information for sustainable soil management and water conservation through improving cultivation and tillage measures.

It is prominently claimed that enhancing forest diversity would play a dual role of nature conservation and climate regulation. While the idea is intuitively appealing, studies show that species richness effects on above‐ground carbon (AGC) are not always positive, but instead unpredictable especially across scales and complex terrestrial systems having large‐diameter and tall‐stature trees. Previous studies have further considered structural complexity and larger trees as determinants of AGC. Yet it remains unclear what drives differential diversity–AGC relationships across vegetation types.Here we test whether structural complexity and large‐sized trees play an influential role in explaining shifting diversity–AGC relationships across vegetation types, using a 22.3‐ha sampled dataset of 124 inventory plots in woodlands, gallery forests, tree/shrub savannas and mixed plantations in West Africa.Natural vegetation had greater species richness and structural complexity than mixed plantations, as expected. In addition, AGC was highest in gallery forests and mixed plantations, which is consistent with favourable environmental conditions in the former and high stocking densities and presence of fast‐growing species in the latter. Significant interaction effects of species richness and vegetation on AGC revealed a vegetation‐dependent species richness–AGC relationship: consistently, we found positive species richness–AGC relationship in both mixed plantations and woodlands, and nonsignificant patterns in gallery forests and tree/shrub savanna. Furthermore, there was a vegetation‐dependent mediation of structural complexity in linking species richness to AGC, with stronger positive structural complexity effects where species richness–AGC relationships were positive, and stronger positive large‐sized trees’ effect where species richness–AGC relationships were neutral.Our study provides strong evidence of vegetation‐dependent species richness–AGC relationships, which operated through differential mediation by structural complexity of the species richness and large trees’ effects. We conclude that even higher species richness in diversified ecosystems may not always relate positively with AGC, and that neutral pattern may arise possibly as a result of larger dominant individual trees imposing a slow stand dynamic flux and overruling species richness effects.A freePlain Language Summarycan be found within the Supporting Information of this article.

Disturbances and environmental heterogeneity are two factors thought to influence plant species diversity, but their effects are still poorly understood in many ecosystems. We surveyed understory vegetation and measured tree canopy cover on permanent plots spanning an experimental fire frequency gradient to test fire frequency and tree canopy effects on plant species richness and community heterogeneity within a mosaic of grassland, oak savanna, oak woodland, and forest communities. Species richness was assessed for all vascular plant species and for three plant functional groups: grasses, forbs, and woody plants. Understory species richness and community heterogeneity were maximized at biennial fire frequencies, consistent with predictions of the intermediate disturbance hypothesis. However, overstory tree species richness was highest in unburned units and declined with increasing fire frequency. Maximum species richness was observed in unburned units for woody species, with biennial fires for forbs, and with near-annual fires for grasses. Savannas and woodlands with intermediate and spatially variable tree canopy cover had greater species richness and community heterogeneity than old-field grasslands or closed-canopy forests. Functional group species richness was positively correlated with functional group cover. Our results suggest that annual to biennial fire frequencies prevent shrubs and trees from competitively excluding grasses and prairie forbs, while spatially variable shading from overstory trees reduces grass dominance and provides a wider range of habitat conditions. Hence, high species richness in savannas is due to both high sample point species richness and high community heterogeneity among sample points, which are maintained by intermediate fire frequencies and variable tree canopy cover.

The effects of Acacia nilotica on Sorghum bicolor and Eragrostis tef yield as well as selected soil properties were evaluated under traditional parkland agroforestry system in the lowlands of Kewot district, North Shewa Zone in order to contribute to understanding of this tree effects on selected soil properties, sorghum and teff yield. A total of ten Acacia nilotica trees were purposively selected based on similar canopy width, height and diameter at breast height. Treatments were laid down on sorghum and teff fields and replicated five times under Randomized Complete Block Design. Soil samples were collected at distances of 2.5m, 5m and 12m from the tree trunk with a depth of 0-10 cm, 10-20 cm and 20-30 cm for soil chemical and physical properties analysis. Soil texture and bulk density were not affected significantly (p>0.05) with distance from the tree trunk while bulk density significantly varied with soil depth (p<0.05). Soil organic carbon, total nitrogen, organic matter and phosphorus concentration increased significantly with decreasing distance from the tree base (p<0.05) and significantly declined with increasing soil depth (p<0.05). The highest soil organic carbon, soil organic matter, total nitrogen and Available Phosphorus concentrations were found under the tree canopy and in surface soil. Soil pH and C/N ratio were least affected by the presence of Acacia nilotica and not significantly varied (P>0.05) with soil depth and distance. Sorghum grain yield reduction (61%) and (32%) was found in the mid canopy and canopy edge respectively. Similarly, Teff grain yield reduction (55.72%) and (33.76%) was found at mid canopy and edge of the tree canopy, respectively. This study revealed that Acacia nilotica negatively affected the grain yield and biomass production of sorghum and teff however, improves soil organic carbon, total nitrogen, organic matter and phosphorus concentration of the soil under its canopy.

Tropical montane forests in the Andes are hotspots for species diversity and constitute important ecosystems for the provision of numerous services critical for local populations, including biomass/carbon accumulation and hydrological regulation. Additionally, in many countries in the region, these forests are being lost or degraded at alarming rates. Understanding their dynamics in terms of the composition, diversity, structure and function is a key challenge in the region that can inform policies for their sustainable management and conservation. This study focused on the use of monitoring data from ground-based permanent plots (part of the Andean Forest Network) in the two main mountain ranges of the Venezuelan Andes to analyze forest structure, diversity and dynamics over six years (2016-2023), and their potential drivers. We found that although the we�er forests of La Mucuy (northeast) and the more seasonal stands of San Eusebio (northwest) are very similar in terms of overall species richness, they show substantial differences in their species assemblages and their biogeographic origins. Both sites share similarities in tree dispersal strategies and stem turnover rates (mean=1.16%/year), but forests in La Mucuy are significantly more productive, with a mean annual woody productivity rate of 3.09±1.42 Mg C.ha-1.y-1, while this rate was 0.73±0.48 Mg C.ha-1.y-1 in SEU plots. Interestingly, although species richness and composition has not shown significant changes during this 6-year period, both sites have increased their total aboveground biomass, acting as a significant carbon sink, which appears to be largely driven by the growth of large trees in these forests. These results emphasize the need of maintaining long-term monitoring efforts to be able to link more explicitly changes in composition, biodiversity and ecosystem services with changes in environmental drivers under climate change scenarios.

The NW Pacific lies in the most productive, rich, and diverse region of the World Ocean. The NW Pacific includes several shallow-water oceanic islands and deep-sea basins differing in depths, hydrology and isolation. The adjacent Arctic Ocean includes the northern Bering and southern Chukchi Sea, areas of high productivity characterized by short food chains and shallow depths. Despite the NW Pacifićs high species richness, characterization of species diversity and species composition in this region remains poorly explored and/or unknown. Here we attempt to discover how geographic boundaries and depth shape current community assemblages in this area by limiting species richness and geographic distribution ranges. All geographic distribution records were extracted from Ocean Biogeographic Information System (OBIS) and Global Biodiversity Information Facility (GBIF). Distribution data were then cleaned, resulting in a final dataset including 324,916 distribution records of 17,414 species ranging from 0 to 10,900 m depth. We calculated the rate of endemicity and alpha species richness per ecoregion. We also showed how species composition and community structure varies between the tropical and temperate NW Pacific and adjacent Arctic Ocean when sampling bias is accounted for using rarefaction. After accounting for sampling bias, the Eastern Philippines had the greatest species richness (for both pelagic and benthic species) in the NW Pacific and its adjacent Arctic Ocean, and the lowest species richness was observed in Papua. Despite the high species richness in the Eastern Philippines, the Yellow Sea and Gulf of Tonkin had the highest benthic species endemicity rates (ca. 70%) and Aleutian Islands had the highest pelagic endemicity rate (ca. 45%) among all other ecoregions. In the NW Pacific, Chordata, Arthropoda, and Mollusca contributed more than 50% to the species composition of the community. In the Arctic Ocean, Arthropoda, Annelida, and Mollusca were the dominant taxa comprising ca. 82% of the species community. Two significantly distinguished clusters (North and South clusters) were identified based on species similarity analysis including ecoregions of the (1) polar Arctic Ocean and temperate North NW Pacific, and (2) tropical and sub-tropical NW Pacific. We also calculated marine species richness hotspots (actual and expected ES50) and centers of endemism in the NW Pacific and adjacent Arctic Ocean. These analyses reveal an opportunity for marine conservation planning effort as reporting species richness and endemicity hotspots could be highly effective in pinpointing and preventing biodiversity loss.

The release of carbon and water from soil organic matter (SOM) was determined with a LECO analyzer (RC‐412) and compared to weight loss data obtained by analysis of soils with a normal thermogravimetric method, SOM fractions obtained by wet chemical extractions and SOM subunits of carbon‐13 NMR spectroscopy of bulk soil samples. Four soil horizons were used for the analysis with the LECO analyzer. Wet chemical data as well as NMR spectra show a specific SOM composition of the soil horizons. The thermoanalytical analysis allows a quantitative separation of carbon and water release, and the thermal diagrams confirm the specificity of the SOM in the different soil horizons. The heating rate in the LECO analyzer with a low temperature progression improves the resolution of the carbon release in comparison to the continuous temperature increase (105°C to l,000°C) of at a speed of 70°C min‐1. The thermostability index Rp can be used to characterize the humification level and provides a semiquantitative carbohydrate estimate in the SOM fraction. The obtained C/O and the C/H ratios are perhaps simple parameters to observe changes in carbon (C), oxygen (O), and hydrogen (H) for characterization of turnover processes and humification of organic matter in soil.

Butterfly populations are naturally patchy and undergo extinctions and recolonizations. Analyses based on more than 2 decades of data on California's Central Valley butterfly fauna show a net loss in species richness through time. We analyzed 22 years of phenological and faunistic data for butterflies to investigate patterns of species richness over time. We then used 18-22 years of data on changes in regional land use and 37 years of seasonal climate data to develop an explanatory model. The model related the effects of changes in land-use patterns, from working landscapes (farm and ranchland) to urban and suburban landscapes, and of a changing climate on butterfly species richness. Additionally, we investigated local trends in land use and climate. A decline in the area of farmland and ranchland, an increase in minimum temperatures during the summer and maximum temperatures in the fall negatively affected net species richness, whereas increased minimum temperatures in the spring and greater precipitation in the previous summer positively affected species richness. According to the model, there was a threshold between 30% and 40% working-landscape area below which further loss of working-landscape area had a proportionally greater effect on butterfly richness. Some of the isolated effects of a warming climate acted in opposition to affect butterfly richness. Three of the 4 climate variables that most affected richness showed systematic trends (spring and summer mean minimum and fall mean maximum temperatures). Higher spring minimum temperatures were associated with greater species richness, whereas higher summer temperatures in the previous year and lower rainfall were linked to lower richness. Patterns of land use contributed to declines in species richness (although the pattern was not linear), but the net effect of a changing climate on butterfly richness was more difficult to discern.

Edge effects and bed size are 2 main landscape-scale parameters that may affect fish in seagrass. We tested their influence on the species richness per unit area and density of fish in 6 Zostera capricorni seagrass beds ranging in size from 2300 to 211 200 m 2 , in the Pittwater estuary, NSW, Australia. The effect of edge interacted with bed size. The species richness was lower in edge than inner regions of the larger beds, but did not differ between regions in smaller beds, in which the species richness was similar to the inner regions of large beds. The density of fish (all species combined) varied with bed size in 1 of the 2 seasons sampled, but not with region. The densities of some individual species were lower in the larger beds compared to smaller beds (5 species), while others were greater (3 species), although for some species this was inconsistent between seasons. We then tested whether species richness and abundance were responding to patch area, perimeter, or perimeter: area ratio (P:A ratio) using artificial seagrass units (ASUs) of different shapes and sizes. All ASU designs had similar total abundances of fish species (per ASU), yet 1 design was smaller in area, so these smaller ASUs had greater species richness per unit area. The ASUs were smaller than the natural seagrass beds, and it seems that, although edge effects appeared in large natural seagrass beds, in smaller patches the total area rather than amount of edge influenced the species richness.

Factors determining soil nutrient distribution in a small-scaled watershed in the purple soil region of Sichuan Province, China