封育和放牧条件下退化荒漠草地土壤种子库特征

连续2年地不同退化程度天然干旱荒漠草原围封后群落的土壤种子库进行研究。结果显示,土壤种子库物种数、种子密度和植物生活型在年际间、封育与放牧样地间及退化梯度问均有明显差异。种子库物种数为封育高于放牧样地;退化梯度相比,物种数除2003年封育样地随退化程度加剧呈减少趋势外,放牧样地及2004年各样地均随退化程度加剧而增加。种子岸密度结果显示．2003年种子库密度明显高于2004年;各封育样地2年中土壤种子库密度显著或极显著（P＜0．01）高于放牧样地;退化梯度相比种子库密度除2003年封育样地随退化程度加剧而急剧增加外,其余各样地种均随退化程度加剧而明显下降。植被生活型分析结果为,2003年以一年生草本植物种出现频率最高,各样地分别达94．0％～98．4％．多年生草本及灌木出现频率则很低,分别为1．59％～5．15％和0．03％～0．4％,2004年则为多年小草本植物种比例上升．且显示出封育高于放牧、退化程度愈轻增幅愈大的趋势。2年的结果显示种子库物种Shannon－Wiener多样性指数和Peilow均匀性系数均以封育低于放牧样地。种子库密度与地上植被盖度相关性分析表．2年结果中仅一年生草本和2003年灌木的土壤种子库密度与相应地上植被盖度之间具相关趋势和显著（P〈0．01）相关。     

The Effects of Timing of Grazing on Plant and Arthropod Communities in High-Elevation Grasslands

Livestock grazing can be used as a key management tool for maintaining healthy ecosystems. However, the effectiveness of using grazing to modify habitat for species of conservation concern depends on how the grazing regime is implemented. Timing of grazing is one grazing regime component that is less understood than grazing intensity and grazer identity, but is predicted to have important implications for plant and higher trophic level responses. We experimentally assessed how timing of cattle grazing affected plant and arthropod communities in high-elevation grasslands of southwest Montana to better evaluate its use as a tool for multi-trophic level management. We manipulated timing of grazing, with one grazing treatment beginning in mid-June and the other in mid-July, in two experiments conducted in different grassland habitat types (i.e., wet meadow and upland) in 2011 and 2012. In the upland grassland experiment, we found that both early and late grazing treatments reduced forb biomass, whereas graminoid biomass was only reduced with late grazing. Grazing earlier in the growing season versus later did not result in greater recovery of graminoid or forb biomass as expected. In addition, the density of the most ubiquitous grassland arthropod order (Hemiptera) was reduced by both grazing treatments in upland grasslands. A comparison of end-of-season plant responses to grazing in upland versus wet meadow grasslands revealed that grazing reduced graminoid biomass in the wet meadow and forb biomass in the upland, irrespective of timing of grazing. Both grazing treatments also reduced end-of-season total arthropod and Hemiptera densities and Hemiptera biomass in both grassland habitat types. Our results indicate that both early and late season herbivory affect many plant and arthropod characteristics in a similar manner, but grazing earlier may negatively impact species of conservation concern requiring forage earlier in the growing season.     

Long-Term Grazing Exclusion Improves the Composition and Stability of Soil Organic Matter in Inner Mongolian Grasslands

Alteration of the composition of soil organic matter (SOM) in Inner Mongolian grassland soils associated with the duration of grazing exclusion (GE) has been considered an important index for evaluating the restoring effects of GE practice. By using five plots from a grassland succession series from free grazing to 31-year GE, we measured the content of soil organic carbon (SOC), humic acid carbon (HAC), fulvic acid carbon (FAC), humin carbon (HUC), and humic acid structure to evaluate the changes in SOM composition. The results showed that SOC, HUC, and the ratios of HAC/FAC and HAC/extractable humus carbon (C) increased significantly with prolonged GE duration, and their relationships can be well fitted by positive exponential equations, except for FAC. In contrast, the HAC content increased logarithmically with prolonged GE duration. Long-term GE enhanced the content of SOC and soil humification, which was obvious after more than 10 years of GE. Solid-state ¹³C nuclear magnetic resonance spectroscopy showed that the ratios of alkyl C/O-alkyl C first decreased, and then remained stable with prolonged GE. Alternately, the ratios of aromaticity and hydrophobicity first increased, and then were maintained at relatively stable levels. Thus, a decade of GE improved the composition and structure of SOM in semiarid grassland soil and made it more stable. These findings provide new evidence to support the positive effects of long-term GE on soil SOC sequestration in the Inner Mongolian grasslands, in view of the improvement of SOM structure and stability.     

Dynamics of Soil Organic Carbon and Aggregate Stability with Grazing Exclusion in the Inner Mongolian Grasslands

Grazing exclusion (GE) has been deemed as an important approach to enhance the soil carbon storage of semiarid grasslands in China; however, it remains unclear how different organic carbon (OC) components in soils vary with the duration of GE. Here, we observed the changing trends of different OC components in soils with increased GE duration in five grassland succession series plots, ranging from free grazing to 31-year GE. Specifically, we measured microbial biomass carbon (MBC), easily oxidizable OC (EOC), water-soluble OC (WSOC), and OC in water stable aggregates (macroaggregates [250–2000 μm], microaggregates [53–250 μm], and mineral fraction [< 53 μm]) at 0–20 cm soil depths. The results showed that GE significantly enhanced EOC and WSOC contents in soils, but caused a decline of MBC at the three decade scale. Macroaggregate content (F = 425.8, P < 0.001), OC stored in macroaggregates (F = 84.1, P < 0.001), and the mean weight diameter (MWD) of soil aggregates (F = 371.3, P < 0.001) increased linearly with increasing GE duration. These findings indicate that OC stored in soil increases under three-decade GE with soil organic matter (SOM) stability improving to some extent. Long-term GE practices enhance the formation of soil aggregates through higher SOM input and an exclusion of animal trampling. Therefore, the practice of GE may be further encouraged to realize the soil carbon sequestration potential of semi-arid grasslands, China.     

Impacts of Grazing and Climate Warming on C Pools and Decomposition Rates in Arctic Environments

Arctic ecosystems are important habitats for Arctic breeding geese which in their turn have a profound impact on the vegetation in these areas. The herbivore pressure is currently on the rise in the region and may interact with climate change to drive changes in both productivity and decomposition rates. In this study, we aim to determine the combined impact of warming and geese on C pools and decomposition in two high Arctic habitats, mesic heath and wet meadow. We employed field-experimental warming and grazing treatments in a fully factorial design and quantified their impact on ecosystems C pools and turnover. High grazing levels reduced vascular biomass and litter C pools at both sites, whereas warming reduced moss biomass at the mesic site only. Grazing increased decomposition rates and reduced the amount of labile C in the soil at the mesic site, whereas warming substantially reduced C concentrations by approximately 25%. Intermediate level of grazing had an opposite effect and resulted in increased soil C storage at the mesic site. In contrast, no effects of the treatment on belowground C cycling were found at the wet site. In conclusion, the two levels of grazing and warming impacted on different aspects of the C cycle investigated in this study. The high grazing and warming treatment promoted reduced carbon storage/decomposition both above- and belowground with the strongest effects seen at the mesic site.     

Impacts of Rotational Grazing on Soil Carbon in Native Grass-Based Pastures in Southern Australia

Rotational grazing management strategies have been promoted as a way to improve the sustainability of native grass-based pasture systems. From disturbance ecology theory, rotational grazing relative to continuous grazing can increase pasture productivity by allowing vegetation to recover after short intense grazing periods. This project sought to assess whether soil organic carbon (SOC) stocks would also increase with adoption of rotational grazing management. Twelve pairs of rotationally and continuously grazed paddocks were sampled across a rainfall gradient in South Australia. Pasture productivity approximated as the normalized difference vegetation index (NDVI) was on average no different between management categories, but when the data from all sites were aggregated as log response ratios (rotational/continuous) a significant positive trend of increasing NDVI under rotational grazing relative to continuous grazing was found (R² = 0.52). Mean SOC stocks (0–30 cm) were 48.3 Mg C ha^-1 with a range of 20–80 Mg C ha^-1 across the study area with no differences between grazing management categories. SOC stocks were well correlated with rainfall and temperature (multiple linear regression R² = 0.61). After removing the influence of climate on SOC stocks, the management variables, rest periods, stocking rate and grazing days, were found to be significantly correlated with SOC, explaining 22% of the variance in SOC, but there were still no clear differences in SOC stocks at paired sites. We suggest three reasons for the lack of SOC response. First, changes in plant productivity and turnover in low-medium rainfall regions due to changes in grazing management are small and slow, so we would only expect at best small incremental changes in SOC stocks. This is compounded by the inherent variability within and between paddocks making detection of a small real change difficult on short timescales. Lastly, the management data suggests that there is a gradation in implementation of rotational grazing and the use of two fixed categories (i.e. rotational v. continuous) may not be the most appropriate method of comparing diverse management styles.     

Habits of the Home: Spatial Hegemony and the Structuration of House and Society in Brazil

This article examines the relation between spatial structure and social practice in a Brazilian fishing town. The sociospatial division of the Brazilian house into rooms with distinct social functions and role relationships helps to define the domestic practices of the family members and socializes them into a conception of social interaction that influences their economic and public practices outside the home. However, the hegemony of this domestic sociospatial structure is not autonomous, but rather stands in dynamic interaction with the public and economic dimensions of the household's reproduction in society. A comparison between canoe fishermen and boat fishermen demonstrates that their different involvement in the economic and public domains of the town affects their interpretation of the architectural structure of the house and differentiates their domestic practices.     

Impacts of recent climate change on terrestrial flora and fauna: Some emerging Australian examples

The effects of anthropogenic climate change on biodiversity are well known for some high‐profile Australian marine systems, including coral bleaching and kelp forest devastation. Less well‐published are the impacts of climate change being observed in terrestrial ecosystems, although ecological models have predicted substantial changes are likely. Detecting and attributing terrestrial changes to anthropogenic factors is difficult due to the ecological importance of extreme conditions, the noisy nature of short‐term data collected with limited resources, and complexities introduced by biotic interactions. Here, we provide a suite of case studies that have considered possible impacts of anthropogenic climate change on Australian terrestrial systems. Our intention is to provide a diverse collection of stories illustrating how Australian flora and fauna are likely responding to direct and indirect effects of anthropogenic climate change. We aim to raise awareness rather than be comprehensive. We include case studies covering canopy dieback in forests, compositional shifts in vegetation, positive feedbacks between climate, vegetation and disturbance regimes, local extinctions in plants, size changes in birds, phenological shifts in reproduction and shifting biotic interactions that threaten communities and endangered species. Some of these changes are direct and clear cut, others are indirect and less clearly connected to climate change; however, all are important in providing insights into the future state of terrestrial ecosystems. We also highlight some of the management issues relevant to conserving terrestrial communities and ecosystems in the face of anthropogenic climate change.     

Response of Vegetation and Soil Carbon and Nitrogen Storage to Grazing Intensity in Semi-Arid Grasslands in the Agro-Pastoral Zone of Northern China

Overgrazing has been the primary cause of grassland degradation in the semi-arid grasslands of the agro-pastoral transition zone in northern China. However, there has been little evidence regarding grazing intensity impacts on vegetation change and soil C and N dynamics in this region. This paper reports the effects of four grazing intensities namely un-grazed (UG), lightly grazed (LG), moderately grazed (MG) and heavily grazed (HG) on vegetation characteristics and soil properties of grasslands in the Guyuan county in the agro-pastoral transition region, Hebei province, northern China. Our study showed that the vegetation height, canopy cover, plant species abundance and aboveground biomass decreased significantly with increased grazing intensity. Similarly, soil organic carbon (SOC) and total nitrogen (STN) in the 0–50 cm were highest under UG (13.3 kg C m⁻² and 1.69 kg N m⁻²) and lowest under HG (9.8 kg C m⁻² and 1.22 kg N m⁻²). Soil available nitrogen (SAN) was significantly lower under HG (644 kg N hm⁻²) than under other treatments (725–731 kg N hm⁻²) in the 0–50 cm. Our results indicate that the pasture management of “take half-leave half” has potential benefits for primary production and livestock grazing in this region. However, grazing exclusion was perhaps the most effective choice for restoring degraded grasslands in this region. Therefore, flexible rangeland management should be adopted in this region.     

Zooplankton Growth,Respiration and Grazing on the Australian Margins of the Tropical Indian and Pacific Oceans

The specific activity of aminoacyl-tRNA synthetases (spAARS), an index of growth rate, and of the electron transport system (spETS), an index of respiration, was measured in three size fractions (73–150 μm, >150 μm and >350 μm) of zooplankton during five cruises to tropical coastal waters of the Kimberley coast (North West Australia) and four cruises to waters of the Great Barrier Reef (GBR; North East Australia). The N-specific biomass of plankton was 3–4-fold higher in the Kimberley than on the GBR in all 3 size classes: Kimberley 1.27, 3.63, 1.94 mg m^-3; GBR 0.36, 0.88 and 0.58 mg m^-3 in the 73–150 μm, >150 μm and >350 μm size classes, respectively. Similarly, spAARS activity in the Kimberley was greater than that of the GBR: 88.4, 132.2, and 147.6 nmol PPi hr^-1 mg protein ^-1 in the Kimberley compared with 71.7, 82.0 and 83.8 nmol PPi hr^-1 mg protein ^-1 in the GBR, for the 73–150 μm, >150 μm and >350 μm size classes, respectively. Specific ETS activity showed similar differences in scale between the two coasts: 184.6, 148.8 and 92.2 μL O₂ hr^-1 mg protein^-1 in the Kimberley, against 86.5, 88.3 and 71.3 μL O₂ hr^-1 mg protein^-1 in the GBR. On the basis of these measurements, we calculated that >150 μm zooplankton grazing accounted for 7% of primary production in the Kimberley and 8% in GBR waters. Area-specific respiration by >73 μm zooplankton was 7-fold higher in the Kimberley than on the GBR and production by >150 μm zooplankton was of the order of 278 mg C m^-2 d^-1 in the Kimberley and 42 mg C m^-2 d^-1 on the GBR. We hypothesize that the much stronger physical forcing on the North West shelf is the principal driver of higher rates in the west than in the east of the continent.     

Impacts of drought and predicted effects of climate change on fish growth in temperate Australian lakes

Climate change is expected to negatively impact many freshwater environments due to reductions in stream‐flow and increases in temperature. These conditions, however, can already be found today in areas experiencing significant drought; current observations of species' responses to droughts can be used to make predictions about their future responses to climate change. Using otolith analysis, we recreated golden perch (Macquaria ambigua) growth chronologies from two temperate lake populations in southeastern Australia over a 15‐year period pre‐ and during a supraseasonal drought. We related interannual growth variation to landscape‐scale changes in temperature and hydrological regimes: fish growth declined as water levels in the lakes dropped during the drought, but this effect was offset by increased growth in warmer years. We hypothesize that golden perch are responding to fluctuations in food availability and intraspecific competition related to water level and to an optimization of physiological growth conditions related to increases in growing season length. Based on our analyses, we made predictions of future growth under a number of climate change scenarios that incorporate forecast deviations in stream‐flows and air temperature. Despite climatic models predicting significant declines in future water availability, fish growth may increase due to a disproportionate lengthening of the growing season. As the two lakes are at the limit of the southerly range of golden perch, our results are consistent with previous findings of climate‐change driven latitudinal range shifts in a poleward direction. We discuss assumptions concerning the constancy of ecological interactions into the future that warrant further study. Our research provides a novel application of biochronological analysis that could be used elsewhere to further our knowledge of species responses to changing environments.     

Field studies on a social lizard: Home range and social organization in an Australian skink,Egernia major

Abstract Although most reptiles have polygynous mating systems without long‐term pair bonds, one lineage of large scincid lizards in Australia is exceptional in this respect. Reports of complex sociality in the genus Egernia led us to conduct the first radiotelemetric field study of a species within this group. Land mullets (Egernia major) are large (60 cm total length), viviparous lizards from rainforest habitats in south‐eastern Australia. To document the spatial ecology and social organization of this species, we captured 12 adult lizards in the Barrington Tops area of eastern New South Wales and implanted them with miniature radiotransmitters. The lizards were released at their sites of capture and located daily for the next 6 weeks. All of the radiotracked lizards had discrete home ranges of approximately 10 000 m², based around well‐defined core areas (approximately 2000–3000 m²). Females tended to move further, and to range over wider areas, than did males. All of the radiotracked lizards lived in social groups consisting of one or more adult males and females plus juveniles of all age classes. Subgroups were apparent within one group of five radio‐tagged lizards: individual animals consistently shared their shelter sites and home ranges with one or more specific individuals. Male/female pairings were more frequent than expected under the null hypothesis of random association among individuals. The data in the present study support anecdotal reports of pair bonds in E. major and support suggestions that the social systems of species in this genus are more complex than those of previously studied reptiles.     

Impacts of Herbicide Application and Mechanical Cleanings on Growth and Mortality of Two Timber Species in Saccharum spontaneum Grasslands of the Panama Canal Watershed

Reforestation has been suggested as a strategy to control Saccharum spontaneum, an invasive grass that impedes regeneration in disturbed areas of the Panama Canal Watershed (PCW). In this study, the effects of different intensities of herbicide application and mechanical cleanings on the growth and mortality of Terminalia amazonia and Tectona grandis saplings were evaluated in S. spontaneum grasslands within the PCW. Both species exhibited greater height, basal diameter, wood volume index, wider crown diameters, deeper live crowns, and lower mortality with increasing intensity of mechanical cleanings and herbicide application. Height and competition of S. spontaneum correlated negatively with intensity of mechanical cleanings and herbicide application. Grass control costs did not differ between tree species but did increase significantly with intensity of mechanical cleanings and herbicide application. We recommend fire suppression, annual herbicide application, and at least four mechanical cleanings per year in Tec. grandis plantations during the first 3 years of plantation establishment. Given the slower initial growth and mortality patterns of Ter. amazonia, aggressive grass control treatments should be continued until individuals are sufficiently large to effectively shade S. spontaneum. Results from this study suggest that reforestation with commercial timber species can rapidly establish and control S. spontaneum growth in the PCW. Reforestation of areas already invaded or at risk of being invaded by S. spontaneum appears to be a viable strategy to reduce its abundance and subsequent negative ecological effects in the PCW.     

Impacts of feral horses in the Australian Alps and evidence‐based solutions

New evidence of impacts by feral horses in Australia's alpine parks systems confirms they endanger threatened species and extensively damage critically endangered bog communities that could take millennia to recover. These impacts are not confounded by effects of deer and accumulate over time, even when only a small number of feral horses (~100) are present. With protected areas representing only a small proportion of the area of the Australian states of New South Wales (9.3%) and Victoria (17%), allowing feral horses to degrade reserves is not a reasonable management compromise, is contrary to the purpose of the protected area system and conflicts with international obligations. Modelling and decades of management experience indicate that trapping alone does not control feral horse numbers. Trapping and fertility control can work in small populations, but not when there are several thousand horses in remote areas. Aerial culling is needed to cost‐effectively and humanely control feral horse populations. The relatively small amount of suffering feral horses experience during a cull is outweighed by (i) avoiding suffering and death of horses from starvation and thirst, (ii) avoiding the suffering of native animals displaced by horses and (iii) avoiding the ethical concerns of driving threatened species towards extinction. Objections to aerial culling on welfare and cultural grounds are contradicted by evidence. Improving knowledge in the general community about what is at stake is long overdue because without this knowledge, small groups with vested interests and unfounded claims have been able to dominate debate and dictate management actions. As a result of ineffective management, horse populations are now expanding and causing well‐documented damage to Australia's alpine parks, placing at risk almost $10M spent on restoration after livestock grazing ended. The costs of horse control and restoration escalate the longer large horse populations remain in the alpine parks. It is crucial that feral horse numbers are rapidly reduced to levels where ecosystems begin to recover. Aerial culling is needed as part of the toolbox to achieve that reduction.     

Home range and territoriality of Australian owlet-nightjars Aegotheles cristatus in diverse habitats

Sedentary Australian owlet-nightjars Aegotheles cristatus roost in cavities year-round, and are thought to mate for life and maintain stable home ranges throughout the year. These factors lead to the prediction that they should be highly territorial, yet nothing is known about their home range requirements or level of site fidelity. I used radio-telemetry coupled with GPS recordings to determine home range size in the semi-arid zone of central Australia (13 birds over two winters) and in a eucalypt woodland in the Northern Tablelands of NSW (14 birds over one calendar year). The mean home range in the eucalypt woodland was 17.7 ha based on the minimum convex polygon (MCP) method and 17.4 ha based on the fixed kernel contour (95%), whereas it was 23.8 ha and 24.1 ha based on the MCP and kernel methods in the desert respectively. With the exception of mated pairs (range overlap 41.9%), there was little overlap among individuals in home range areas (<13.0%), even in the densely populated woodland. Home range size did not differ significantly between seasons or study sites; nor was it correlated with arthropod abundance. Owlet-nightjars exhibited high site fidelity, using the same home range throughout the year with a 68% overlap between seasons. These data, plus anecdotal records of aggression and vocalizations, suggest that this species is highly territorial, yet individuals live in close proximity to conspecifics. The degree of territoriality may be due to the obligate cavity roosting behaviour of owlet-nightjars and the need to defend areas with known roost hollows.     

Habitat Complexity and Invasive Species: The Impacts of Gamba Grass (Andropogon gayanus) on Invertebrates in an Australian Tropical Savanna

Habitat complexity is an important factor structuring local faunal assemblages. Many invasive plant species alter vegetation complexity because they are both functionally and structurally different from native flora. This study investigated the effects of an invasive grass (Andropogon gayanus Kunth.), which is invading undisturbed savannas in northern Australia. Although A. gayanus is a similar lifeform to that dominant in the native understory (i.e., a C4 grass), it is structurally different and significantly alters habitat complexity. We, therefore, hypothesized that there would be a substantial effect of the invasive grass on ant, spider, and other invertebrate assemblages. Contrary to our hypothesis, there was no effect of A. gayanus on ant species richness, abundance, or composition, nor were spiders or other invertebrates affected. Instead the change in weather conditions with season was more important in structuring the local invertebrate assemblages. Change in habitat complexity was most pronounced vertically, rather than horizontally at ground level, thus although there was a clear difference in the vertical structure between invaded and noninvaded habitats, the limited invertebrate response to different A. gayanus densities suggests some invertebrates are less sensitive to vertical changes in vegetation structure.     

阿拉善荒漠连续放牧对三趾跳鼠巢区的影响

三趾跳鼠(Dipus sagitta)是内蒙古西部荒漠草原和沙地的优势害鼠,巢区研究对了解探讨其繁殖策略和种群动态规律有着重要的理论和实践意义。本研究通过2012~2014年的野外标志重捕实验,对三趾跳鼠的巢区在连续放牧和禁牧条件下的变动特征进行了分析。结果表明,连续放牧区雌性三趾跳鼠在6月的巢区范围显著大于禁牧区(P0.05);禁牧区雄性三趾跳鼠的巢区仅在7月份显著大于连续放牧区(P0.05),其他季节没有显著差异(P0.05)。放牧对雄性巢区无显著影响(P0.05),但连续放牧使雌性三趾跳鼠巢区范围显著大于禁牧区。雌性与雄性三趾跳鼠巢区均与一年生草本生物量存在正相关关系。这些结果表明,相对于雄性三趾跳鼠来说,雌性对由放牧导致的食物资源变化比较敏感,这种现象在哺乳期更为显著;繁殖是影响雄性三趾跳鼠巢区的因素之一。因此,保卫资源假说的理论可能是放牧导致三趾跳鼠巢区变化的重要原因之一。     

Woodlands on farms in southern New South Wales: A longer-term assessment of vegetation changes after fencing

Summary Fencing incentive programmes have been widely used throughout Australia to assist landholders to fence remnant woodland vegetation, to control grazing and improve native vegetation condition. This study investigated vegetation and soil condition in remnant woodlands fenced for 7–9 years in the Murray catchment area in southern New South Wales. Surveys were undertaken at 42 sites, where vegetation condition was assessed in paired fenced and unfenced sites. Semi‐structured interviews were also conducted with landholders to gather management information. Woodlands surveyed were Yellow Box/Blakely's Red Gum (Eucalyptus melliodora/E. blakelyi, 15 sites), Grey Box (E. microcarpa, 13 sites) and White Cypress Pine (Callitris glaucophylla, 14 sites). Fencing resulted in a range of responses which were highly variable between sites and vegetation types. In general, fenced sites had greater tree regeneration, cover of native perennial grasses, less cover of exotic annual grasses and weeds, and less soil compaction than unfenced sites. However, there was greater tree recruitment in remnants to the west of the study area, and tree recruitment was positively correlated with time since fencing. Within sites, tree recruitment tended to occur in more open areas with a good cover of native perennial grasses, as compared to sites with a dense tree canopy, or dominated by exotic annuals grasses or weeds. Forty‐eight per cent of fenced sites had no tree regeneration. There was a significant decline in native perennial grasses, and increase of several unpalatable weeds in many fenced areas, suggesting certain ecological barriers may be preventing further recovery. However, drought conditions and associated grazing are the most likely cause of this trend. A range of grazing strategies was implemented in fenced sites which require further research as a conservation management tool. Continued long‐term monitoring is essential to detect key threats to endangered woodland remnants.