Grass Areas Research Articles

A survey for the Critically Endangered Liben Lark Heteromirafra archeri in Somaliland, north-western Somalia

The Critically Endangered Archer's Lark (now Liben Lark) Heteromirafra archeri was formerly considered to be endemic to north-western Somalia and known only from the Tog Wajaale Plain, where 18 specimens were collected between 1918 and 1922. Fifteen visits between 1970 and 2008 failed to relocate the species there, although popula- tions are now known from adjacent Ethiopia. We conducted three days of intensive surveys on the Tog Wajaale Plain in May 2010. Despite the three other lark species present being in full display, and H. archeri being recorded to have bred in early June, no Liben Larks were found. Vegetation structure surveys indicated that the plain has a taller and denser growth of grass than either of the other known localities for Liben Lark (the Liben and Jijiga Plains) making Tog Wajaale Plain seem superficially more suitable for the species, which prefers areas of taller grass elsewhere. However, previous large-scale agricultural activities may have altered the composition of grass species and precipitated the observed invasion of exotic weeds, notably Parthenium hysterophorus. Importantly, the Tog Wajaale Plain has a greater density of bushes than either the Liben or Jijiga Plains, possibly making ground-nesting birds more susceptible to predation by perch hunters.

Monitoring the Distribution and Dynamics of an Invasive Grass in Tropical Savanna Using Airborne LiDAR

The spread of an alien invasive grass (gamba grass—Andropogon gayanus) in the tropical savannas of Northern Australia is a major threat to habitat quality and biodiversity in the region, primarily through its influence on fire intensity. Effective control and eradication of this invader requires better insight into its spatial distribution and rate of spread to inform management actions. We used full-waveform airborne LiDAR to map areas of known A. gayanus invasion in the Batchelor region of the Northern Territory, Australia. Our stratified sampling campaign included wooded savanna areas with differing degrees of A. gayanus invasion and adjacent areas of native grass and woody tree mixtures. We used height and spatial contiguity based metrics to classify returns from A. gayanus and developed spatial representations of A. gayanus occurrence (1 m resolution) and canopy cover (10 m resolution). The cover classification proved robust against two independent field-based investigations at 500 m2 (R2 = 0.87, RMSE = 12.53) and 100 m2 (R2 = 0.79, RMSE = 14.13) scale. Our mapping results provide a solid benchmark for evaluating the rate and pattern of A. gayanus spread from future LiDAR campaigns. In addition, this high-resolution mapping can be used to inform satellite image analysis for the evaluation of A. gayanus invasion over broader regional scales. Our research highlights the huge potential that airborne LiDAR holds for facilitating the monitoring and management of savanna habitat condition.

The Impact of Road Construction on a Community of Farmland Birds

Birds are commonly used as tools in environmental monitoring. Bird population changes were studied during construction of the new Vuosaari harbour in 2001–2011. The aim of the monitoring programme was to determine the impacts of road construction on bird populations in the Osterangen agricultural area (Helsinki, Finland). Our results indicate that the number of species and territories increased during and after construction, with more territories located closer to the road than before the road was constructed. Thus, road construction resulted in a momentary positive impact on bird populations. New grass and bush areas and even large rocky outcrops clearly benefited some species such as the threatened northern wheatear. The bird populations declined slightly several years later, probably as a result of habitat succession.

Interspecific Interactions and Habitat Use by Prairie Voles (Microtus ochrogaster) and Meadow Voles (M. pennsylvanicus)

Interspecific competition can influence patterns of habitat use by small mammals. We examined the effects of interspecific interactions on habitat use by prairie voles (Microtus ochrogaster) and meadow voles (M. pennsylvanicus), two species that co- occur in grass habitats in east-central Illinois, but differ in their tolerance of sparse cover (prairie voles are more tolerant than meadow voles of sparse cover). We conducted a species-removal study in open populations, a species-addition study with enclosed populations, and dyadic encounters in the field, using mown and unmown grass areas, and in the laboratory. In the species-removal study, we found a positive response of prairie voles to removal of meadow voles from unmown grass habitat, and of meadow voles to removal of prairie voles from mown grass habitat. Additionally, when both species were present in control sites, prairie voles were most abundant in mown grass and meadow voles in unmown grass. In enclosures we confirmed greater tolerance of sparse cover by prairie voles (similar numbers of individuals in mown and unmown sites) than meadow voles (more individuals in unmown than mown sites), and these patterns were unaffected by addition of the other species. In dyadic encounters conducted in the field, male prairie voles were dominant over male and female meadow voles in mown grass habitat, whereas female meadow voles were dominant over male and female prairie voles in unmown grass habitat. These dominance relationships, which are consistent with the known social systems of the two species, were not observed when dyadic encounters were conducted in the laboratory in a neutral arena that lacked structural habitat cues. Taken together, our data confirm differences between prairie voles and meadow voles in tolerance for sparse cover and indicate a role, though limited, for interspecific competition in reinforcing patterns of habitat use by each species.

Método prático e eficiente para estimar a área foliar de gramíneas forrageiras tropicais

O método aqui proposto, denomidado de Área Foliar – Universidade Federal do Tocantins (AFUFT) baseia-se em três medidas da folha (comprimento total, largura na base do limbo e largura no meio do limbo), decompondo-a em um triângulo e um trapézio para o calculo da AF. O AFUFT (método II) foi comparado com três métodos: método I – indireto, com uso de aparelho de interceptação luminosa (SunScan®); método III – segmenta as folhas em partes de 10 cm, seguido de medida da largura destes segmentos; método IV – utiliza-se scanners e programa computacional (aqui considerado como método padrão). As quatro metodologias foram testadas em blocos casualisados, sendo os blocos as 24 parcelas (4,0 m x 1,0 m) de Urochloa brizantha cv. ‘Marandu’. O método AFUFT apresentou os maiores coeficientes de correlação (r= 0,99; p

Influence of shrub encroachment on CT-measured soil macropore characteristics in the Inner Mongolia grassland of northern China

The Inner Mongolia grassland of northern China is extensively affected by shrub encroachment. However, the influence of shrub encroachment on soil architecture is not well understood. The objective of this study was to quantify the architecture of soils beneath the shrub canopy and in the adjacent interspace grass area following the establishment of a shrub Caragana microphylla Lam. Study treatments were three transition states of C. microphylla that represent 1.32%, 12.96%, and 40.12% shrub densities and the grass patch as the control. A total of eighteen soil cores (0–50cm deep) were taken at the three sites with 3 replicates. At each site, three cores were from the shrub canopy and three from the grass patch, and cores were scanned with a GE HISPEED FX/I Medical Scanner. Numbers of macropores, macroporosity and macropore equivalent diameter within the 50cm soil profile were interpreted from X-ray computed tomography to analyze soil architecture. The results indicated that shrub encroachment significantly influenced soil macropores. Soils under shrub canopy had greater macroporosity, and developed deeper and longer macropores than those in the interspace grass. X-ray CT showed that macroporosity was 1.4–3.4 times greater in soil under C. microphylla L. than interspace grass. The intensity of shrub encroachment also had noticeable influences on soil macropore characteristics. Soil macroporosity decreased as shrub encroachment increased. In the grass patch, macropores were distributed mainly in the 0–200mm soil layer, while in the shrub patch, they were found throughout the 0–400mm soil layer. The large number of macropores found in soil under the shrub canopy can be attributed to greater root development and subsequent root decay. We speculate that a continual increase of anthropogenic disturbance would further lower the macroporosity of grasses, leading to an increase of surface flow and the decrease of infiltration, and macropore architecture could cause transport of water to the deeper soil layers in the shrub patches than in the grass patches.

Salinity-induced responses and resistance in Trifolium repens L.

White clover (Trifolium repens L.) is a commonly cultivated legume with good ground cover potential often used with companion grass species in urban grassed areas. The effect of increased soil salinity on plant growth is an urgent problem in cities where NaCl is used as a de-icing material. The aim of this research was to examine the effect of different salinity levels and K supply-induced responses and tolerance in the T. repens L. variety ‘Daile’, a variety which is used in urban greenery. To analyze the impact of increased soil salinity and the antagonistic effect of K, the effect of gradually increasing NaCl (0, 20, 40, 60, 80, 100mM) and K (+0, +100, +200, +300mg/L) levels on T. repens plants was investigated in a pot experiment. Concentrations of 12 nutrients, Na and Cl were determined in the plant shoots and roots, as well as plant weight, Pv/Fm, P index (photosynthetic performance) and proline content. The results revealed that increased substrate salinity led to accumulation of both Na and Cl in tissues of T. repens and significantly reduced Mg. Na and Cl concentration in the plant shoots increased in accumulative manner, but in the roots, the concentration of both elements increased in the treatments with applied NaCl concentrations up to 60mM. In the roots, a significant decrease in N, K, Mg, S, Mo and an increase in Na, Cl, Ca, Fe, Mn, Cu, Zn content was detected with increasing substrate salinity. Elevated soil salinity had a minor impact on the photosynthetic performance of T. repens. A significant decline in the fresh and dry biomass of the plant shoots was measured in all salinity treatments. In conditions of increasing soil salinity and K content, T. repens possessed several mechanisms of adaptive value, as well as changes in mineral nutrition. According to the obtained results, cultivation of T. repens variety ‘Daile’ in urban areas with slight or moderate salinity is possible.

Algerian hedgehog (Atelerix algirus Lereboullet, 1842) habitat selection at the northern limit of its range

The Algerian hedgehog is an endemic, Mediterranean, insectivorous mammal which inhabits North Africa, the Eastern Iberian Peninsula, the Canary and Balearic Islands and several Mediterranean islands. Given evidence of population declines coupled with the limited information available on this species, studies are needed to contribute to a better understanding of this hedgehog. With this aim, and in particular to understand biological aspects as well as those of habitat selection, 14 Algerian hedgehogs were radio tracked in the species’ northern limit of distribution, (Baix Llobregat, a coastal district lying a few kilometres south of Barcelona City) between 2007 and 2010. The results showed that Algerian hedgehogs positively selected open grass areas and scrubs, and used fields when available, while rejecting forest and urban areas. No evidence for sex or age related patterns emerged from the data regarding home range size and overlap between individuals, although adult males have larger home ranges and move longer distances per hour than females.

Empirical Model for Calculating the Peak Discharge and The Time Delay of Flood of Synthetic Hydrograph Unit in Sumbawa

This research was carried out in Sumbawa island, it aims to determine: 1) the value of Snyder’s CT and CP coefficient of the synthetic unit hydrograph; 2) the empirical model to estimate of CT and CP coefficient; 3) the empirical model to estimate the peak flow and time lag of synthetic unit hydrograph. Based on rainfall – runoff data, Snyder’s T and CP coefficient of the synthetic unit hydrograph can be derived by syntheti means. The empirical model of CT and CP coefficient can be estimated by using the stepwise method of the multiple regression models. Measurable characteristics of watershed, including watershed area (LDP), length of main river (PSU), slope of watershed (KIM), forest area (LHT), sawah area (LSW), tegal area (LTG), grass area (LRUM), and mean annual rainfall (CHJ) are used to estimate these model. The most appropriate model is selected from a statistical test. Result of analysis show that the model can be used to estimate of Snyder’s CT and CP coefficient. These model can be used to make the empirical model to estimate the peak flow and time lag of synthetic unit hydrograph of ungauged watershed in Sumbawa island.

Objectively measured differences in physical activity in five types of schoolyard area

Physical activity (PA) in childhood is related to a multitude of short- and long-term health consequences. School recess can contribute with up to 40% of the recommended 60min of daily moderate-to-vigorous physical activity (MVPA). This paper aims to investigate how schoolchildren use different schoolyard areas during recess and whether these areas are associated with different levels of PA. Time spent by 316 students (grade 5–8) in five types of schoolyard area was measured during at least two days and four separate recess period per person (in total 1784 recess periods), using global positioning system (GPS) and the level of activity was measured using accelerometers. Total time spent and proportions of time spent sedentary and in MVPA were calculated per area type. Significant differences in PA levels were found. Grass and playground areas had the highest proportion of time in MVPA and solid surface areas had the highest proportion of time spent sedentary. Boys and children spent a higher proportion of time in MVPA. Girls accumulated more sedentary time in all area types compared to boys. This finding emphasizes the importance of investigating various settings and features in schoolyards in promoting PA. Grass and playground areas may play an important role in promoting PA in schoolyards, while a high proportion of time in solid surface areas is spent sedentary. In future, more detailed studies of the exact schoolyard setting using a combination of GPS, accelerometer and direct observation would be beneficial.

Riparian land-use impacts on bank erosion and deposition of an incised stream in north-central Iowa, USA

Stream bank erosion and deposition are complex phenomena because of the many factors that influence them. These factors can be spatial such as bank aspect, height and slope or temporal such as seasonal and yearly precipitation and streamflow events. Riparian land-use also has a major influence. This study investigated for two years, spatial and temporal patterns and dominant geomorphologic processes of stream bank erosion and deposition along a 10km reach of Bear Creek in north-central Iowa, USA. The channel sub-reaches used were adjacent to a riparian forest buffer, a perennial grass filter and a continuously grazed pasture. Two plots were placed in each sub-reach; one on a north-facing outside bank (north-bank) and the other on a south-facing outside bank (south-bank). Each plot had two photo-electronic erosion pins (PEEPs) placed at 1/3 of the bank height (bottom-bank) and the other at 2/3 of the bank height (top-bank). PEEP daily measurements were compared to daily precipitation and streamflow. The continuously grazed pasture banks had the highest erosion rates. The grass area banks had approximately equal rates of erosion and deposition. The riparian forest buffer banks had high erosion rates during the second year. In the continuously grazed pasture, fluvial entrainment was the dominant erosion process, although minor mass failures also caused erosion. In the riparian forest buffer most erosion was recorded after moderate streamflows removed the bank soil loosened by freeze–thaw cycling. This occurred in late winter/early spring, when trees provide primarily mechanical but not hydraulic reinforcement to stream banks and on the lower part of the banks that have less extensive root networks. Overall, stream bank erosion and deposition in each sub-reach occurred during different time periods and under different processes and conditions. This indicates the need for continuous erosion and deposition measurements along with continuous soil moisture, soil temperature and streamflow measurements to fully comprehend these erosion phenomena.

Effects of Vegetation Structure and Artificial Nesting Habitats on Hatchling Sex Determination and Nest Survival of Diamondback Terrapins

Abstract It is often the case that multiple factors contribute to wildlife population declines such that management will require simultaneous, integrated interventions to stabilize and recover populations. Diamondback terrapins Malaclemys terrapin are a species of high conservation priority, and local populations can be threatened by multiple factors, including bycatch in commercial and recreational crab pots, vehicle strikes on coastal roads, nest depredation from subsidized and introduced predators, and terrestrial habitat alteration. Mitigation of just one of these factors will often be insufficient for recovering at-risk populations; thus, information to manage multiple threats is needed. We measured the effects of natural vegetation structure and constructed (artificial) nesting habitat on hatchling sex ratios and nest depredation for a declining terrapin population on Jekyll Island, Georgia. Nest temperatures were highest on constructed nesting mounds, intermediate in open grass areas, and coolest under the shrub-dominated hedgerows. Higher nest temperatures led to shorter incubation times for nests on mounds and open habitat, such that all surviving nests on nesting mounds and open areas produced female hatchlings. In contrast, surviving nests under hedge produced 85% male hatchlings. Raccoon Procyon lotor predation rates of simulated (chicken egg) nests were highest on nesting mounds (95.3%), followed by hedge (84.4%) and open habitats (45.2%). Our results demonstrate that vegetation management can positively affect both production of female hatchlings and nest survival. Artificial nest mounds were successful at producing female hatchlings, but we documented high predation of simulated (chicken egg) nests despite structures to exclude predators. Further modifications to nest boxes atop constructed nesting mounds are needed for these devices to effectively contribute to population management. We suggest the relatively low cost and maintenance associated with removing shrubs and trees can be a viable strategy to manage large areas of nesting habitat for the increased production of female turtles, and to reduce the impacts of subsidized predators.

A novel mechanism for grazing lawn formation: large herbivore‐induced modification of the plant–soil water balance

Summary Large herbivores play a key role in creating spatial heterogeneity through the formation of grazing lawns. Recent research suggests that the currently accepted nutrient‐based theory on the formation of these grazing lawns cannot universally explain their formation in all ecosystems where they are found. We developed and investigated an alternative hypothesis on grazing lawn formation and maintenance based on herbivore effects on the plant–soil water balance. We propose that large herbivores change the soil water balance in grazing lawns through defoliation and soil compaction, causing a shift in vegetation composition towards a drought‐tolerant plant community. Investigating this idea in a tropical savanna, we indeed found profound differences in grazing lawn soil properties and water balance. In particular, defoliation increased soil temperatures and potential evaporation rates while soil compaction increased bulk density and decreased water infiltration rates, especially on fine‐textured soils. Soil moisture was therefore generally much lower in grazing lawns than in adjacent bunch grass areas. Furthermore, we found that grazing lawn species show drought‐tolerant traits, with higher leaf sodium levels, suggesting evolutionary adaptation to these herbivore‐induced dry conditions. However, leaf water potentials did not differ between grazing lawn and bunch grass species. Synthesis. This study shows that large herbivores might form grazing lawns through previously underestimated effects on water balance. Thus, future studies on large herbivore effects on vegetation should increasingly focus on additional pathways of soil compaction and defoliation. While nutrient‐based processes driving grazing lawn formation may operate during the wet season in savannas, we suggest that water balance‐based processes are additionally important during the dry season.

Public approval plus more wildlife: twin benefits of reduced mowing of amenity grass in a suburban public park in Saltdean, UK

Abstract We examined the effects of reduced mowing on wildflower bloom and flower‐visiting insects in the Saltdean Oval, a 6 ha suburban public park in Saltdean, UK. In 2012, a novel management regime was initiated in which approximately half the grass area was left uncut, with the plan being to mow it once per year in autumn. In spring 2013, we set up four blocks, with each block subdivided into four 30 × 5 m strips treated under different mowing regimes: (a) regular mowing every 2 weeks all spring and summer, (b) regular mowing until 2 June, (c) regular mowing until 5 July, and (d) no mowing. The abundance of both flowers and flower‐visiting insects increased significantly with reduced mowing, being ca. 3 and 5 times greater in (d) than (a), respectively, with (b) and (c) intermediate. Mowing intensity, however, had a weak effect on wildflower species richness, which was only lower in (a). A 1 km bee, butterfly, and moth transect walk, 500 m within the long grass part of the park and 500 m within the short, recorded ca. 50× greater insect abundance in the long grass. A questionnaire of public opinion found that 97% of park visitors favoured encouraging insects and wildflowers. In terms of enjoyment of the park, 26% said that it had increased, 64% said that it stayed the same, and 10% said that it decreased. These results present an encouraging example of a potential win–win situation in urban land management change, where the interests of humans and wildlife are aligned, thereby making the goals of conservation easier to achieve.

Foraging site recursion by forest elephants Elephas maximus borneensis

Abstract Recursion by herbivores is the repeated use of the same site or plants. Recursion by wild animals is rarely investigated but may be ubiquitous. Optimal foraging theory predicts site recursion as a function of the quality of the site, extent of its last use, and time since its last use because these influence site resource status and recovery. We used GPS collars, behaviour and site sampling to investigate recursion to foraging sites for two elephant Elephas maximus borneensis herds in the Lower Kinabatangan Wildlife Sanctuary, Borneo, over a 12 month period. Recursion occurred to 48 out of 87 foraging sites and was most common within 48 hours or between 151–250 days, indicating two different types of recursion. Recursion was more likely to occur if the site had previously been occupied for longer. Moreover, the time spent at a site at recursion was the same as the time spent at the site on the first occasion. The number of days that had passed between the first visit and recursion was also positively correlated with how much time was spent at the site at recursion. Habitat type also influenced the intensity of site-use, with more time spent at recursion within riverine/open grass areas along forest margins compared to other habitat types. Recursion is a common behaviour used by the elephants and its pattern suggests it may be a foraging strategy for revisiting areas of greater value. The qualities of recursion sites might usefully be incorporated into landscape management strategies for elephant conservation in the area [Current Zoology 60 (4): 551–559, 2014].

Sex-biased space-use response to urbanization in an endemic urban adapter

Urbanization impacts on the composition and distribution of wildlife. The tawny frogmouth (Podargus strigoides) is an endemic, nocturnal bird species widespread throughout Australia with recent research highlighting high densities within urban environments. The aim of this study was to investigate home-range size and land-use in response to a gradient of urbanization by determining (a) the key land-use types influencing home-range size and location in the urban landscape; (b) whether urbanization impacts on home-range size; and (c) whether the response to urbanization is gender specific. Twelve birds, seven male and five female were radio-tracked within a study zone located in Melbourne, Australia. We used minimum convex polygons (MCP) 95% and 50% fixed-kernel isopleths to calculate home-range size and areas of core use within each home-range. In both the landscape and core areas of their home-range, birds positioned their home-range in areas with more trees, avoiding impervious surfaces and utilizing grassed areas. Male mean kernel home-range was 17.65±4.35ha and female 6.55±1.40ha. Male home-ranges contained higher levels of impervious surfaces than females. Modelling demonstrated that as urbanization intensified the home-range size of males increased whereas female home-ranges remained static in size. This research identifies land-use selection and highlights the possibility that spatial behaviour in the species is sex-biased in response to a gradient of urbanization.

Topographic and spectral data resolve land cover misclassification to distinguish and monitor wetlands in western Uganda

Wetlands provide vital wildlife habitat and ecosystem services, but changes in human land use has made them one of the world’s most threatened ecosystems. Although wetlands are generally protected by law, growing human populations increasingly drain and clear them to provide agricultural land, especially in tropical Africa. Managing and conserving wetlands requires accurately monitoring their spatial and temporal extent, often using remote sensing, but distinguishing wetlands from other land covers can be difficult. Here, we report on a method to separate wetlands dominated by papyrus (Cyperus papyrus L.) from spectrally similar grasslands dominated by elephant grass (Pennisetum purpureum Schumach.). We tested whether topographic, spectral, and temperature data improved land cover classification within and around Kibale National Park, a priority conservation area in densely populated western Uganda. Slope and reflectance in the mid-IR range best separated the combined papyrus/elephant grass pixels (average accuracy: 86%). Using a time series of satellite images, we quantified changes in six land covers across the landscape from 1984 to 2008 (papyrus, elephant grass, forest, mixed agriculture/bare soil/short grass, mixed tea/shrub, and water). We found stark differences in how land cover changed inside versus outside the park, with particularly sharp changes next to the park boundary. Inside the park, changes in land cover varied with location and management history: elephant grass areas decreased by 52% through forest regeneration but there was no net difference in papyrus areas. Outside the park, elephant grass and papyrus areas decreased by 61% and 39%, mostly converted to agriculture. Our method and findings are particularly relevant in light of social, biotic, and abiotic changes in western Uganda, as interactions between climate change, infectious disease, and changing human population demographics and distribution are predicted to intensify existing agricultural pressure on natural areas.

Adopter-dog interactions at the shelter: Behavioral and contextual predictors of adoption

Millions of unwanted pets enter animal shelters each year in the USA, but only a portion leave alive. Previous research has found that morphology and in-kennel behavior influence adoption. The current study evaluated whether any behaviors exhibited by dogs during an out-of-kennel interaction with a potential adopter predicted adoption. In addition, we evaluated whether other predictors such as the morphology of the dog, intention to adopt a dog that day, and location of the interaction influenced adoption. Finally, the study assessed correspondence between the potential adopters’ answers on a questionnaire and the dogs’ behavior during the interactions. The behavior of shelter dogs in out-of-kennel interactions with potential adopters was observed (n=250). After each interaction, visitors were given a questionnaire to indicate their reasons for adopting or not adopting that specific dog. The vast majority of shelter visitors only requested to interact with only a single dog and the average duration of interaction was 8min. Only two behaviors: ignoring play initiation by and lying in proximity to the potential adopter, but no morphological variables, influenced adoption decisions. Dogs that were adopted spent half as much time ignoring play initiation by and twice as much time lying in proximity to the adopter than dogs that were not adopted. The probability (P) of adoption was higher in a smaller outdoor concrete area (P=0.423) than in both large grass area (P=0.320) or an indoor room (P=0.229). Intention to adopt a dog that day resulted in the highest probability of adoption (P=0.586), whereas an intention to not adopt resulted in a low probability (P=0.102). Dogs that were labeled as not social by non-adopters after an interaction had higher scores than average in ignoring play initiations. However, non-adopter reports did not exactly correspond with the dogs’ behavior during the interactions. Our findings may be used to develop targeted training programs for shelter dogs.

Foraging Relationships Between Elephants and Lantana camara Invasion in Mudumalai Tiger Reserve, India

AbstractLantana camara is a widespread exotic invasive species in India, capable of dominating and displacing native forage species. We investigated whether L. camara was associated with variation in elephant foraging behavior in Mudumalai Tiger Reserve, India. The behavioral responses of elephants to L. camara were assessed from feeding and stepping rates. Elephants were never observed to feed on L. camara, but rather fed on grass and browse present within and around L. camara patches. A multiple regression analysis showed that feeding rates were negatively associated with L. camara invasion (F1, 55 = 4.26, R2 = 0.07), but not stepping rates. Instead, grass cover and browse density were associated with stepping rates (F2, 55 = 11.16, R2 = 0.30). Path analysis indicated that the total effect of L. camara on feeding rates was 11 percent (β = −0.24) less than the direct negative association (β = −0.27) owing to a positive indirect association of L. camara with feeding rates through grass cover and browse density (β = 0.03), while stepping rates were negatively associated with grass cover (β = −0.39) and positively associated with browse density (β = 0.38). Our results indicate that L. camara appears capable of modifying feeding rates of elephants, likely through a loss of grass areas due to L. camara invasion. Experimental work is needed to test for causal relationships among the variables we measured, to enhance our understanding of how invasive weeds modify elephant behavior.

Leaf area, chlorophyll content, and relative growth rate of grass on different shading and fertilization

Plant morphology and physiology such as leaf area, total chlorophyll, and chlorophyll a/b ratio were affected by shading and fertilization. An experiment was conducted in Indonesian Research Institute for Animal Production (IRIAP) Ciawi, West Java. The objective of this study was to determine the morphology and physiology adaptation of three short grasses species for grazing namely Paspalum notatum, Brachiaria humidicola, Stenotaphrum secundatum on different shading and fertilization level. The experiment was arranged in split-split plot design. The main plot was shading level (0, 38, 56%); sub-plot was fertilizer dosage (0, 100, and 200 kg N/ha) while sub-sub plot was grass species. The results showed that leaf area were significantly different on different grass species, and there was interaction between shading and species on total leaf area. P. notatum on 38% shading level has the highest total leaf area (240.2 cm 2 ). S. secundatum and P. notatum had a better adaptation in shading area compared to B. humidicola by increasing of total chlorophyll and decreasing of chlorophyll a/b ratio. Relative growth rate (RGR) of P. notatum and S. secundatum were increased by the increasing shading level. On the other hand relative growth rate of B. humidicola was decreased by the increasing shading level. Leaf area, chlorophyll content, and RGR were not significantly affected by fertilization dosage. Key Words : Shading, Fertilization, Adaptation, Growth, Chlorophyll